OFFICE OF THE FEDERAL COORDINATOR FOR

METEOROLOGICAL SERVICES AND SUPPORTING RESEARCH

U.S. DEPARTMENT OF COMMERCE/ National Oceanic and Atmospheric Administration

Washington, DC

May 2012

National Hurricane

Operations Plan

FCM-P12-2012 Incorporates Change 2, 12 October 2012
THE INTERDEPARTMENTAL COMMITTEE FOR METEOROLOGICAL SERVICES AND 

SUPPORTING RESEARCH (ICMSSR) 

MR. SAMUEL P. WILLIAMSON, CHAIRMAN 

Federal Coordinator 

MR. THOMAS PUTERBAUGH 

Department of Agriculture 

DR. JOHN (JACK) L. HAYES 

Department of Commerce 

RADM DAVID TITLEY, USN 

United States Navy 

Department of Defense 

DR. FRED P. LEWIS 

United States Air Force 

Department of Defense 

MR. RICKEY PETTY 

Department of Energy 

MR. JOE WALL (ACTING) 

Science and Technology Directorate 

Department of Homeland Security 

MR. JOHN VIMONT 

Department of the Interior 

MR. MARK KEHRLI 

Federal Highway Administration 

Department of Transportation 

 MR. PAUL FONTAINE (ACTING) 

Federal Aviation Administration 

Department of Transportation 

DR. JONATHAN M. BERKSON 

United States Coast Guard 

Department of Homeland Security 

DR. DAVID R. REIDMILLER 

Department of State 

DR. S. T. RAO 

Environmental Protection Agency 

MR. PATRICK HERNANDEZ (ACTING) 

Federal Emergency Management Agency 

Department of Homeland Security 

DR. RAMESH KAKAR 

National Aeronautics and Space 

 Administration 

DR. MICHAEL MORGAN 

National Science Foundation 

MR. DONALD E. EICK 

National Transportation Safety Board

MS. JENNIFER UHLE (ACTING) 

U.S. Nuclear Regulatory Commission 

COL WILLIAM CARLE, Secretariat 

Office of the Federal Coordinator for 

Meteorological Services and Supporting Research 

Cover Image 

Hurricane Irene, 27 August 2011. Credit: NOAA. 
FEDERAL COORDINATOR 

FOR 

METEOROLOGICAL SERVICES AND SUPPORTING RESEARCH

8455 Colesville Road, Suite 1500 

Silver Spring, Maryland 20910 

301-427-2002 

http://www.ofcm.noaa.gov/

NATIONAL HURRICANE OPERATIONS PLAN

http://www.ofcm.noaa.gov/nhop/12/nhop12.htm

FCM-P12-2012 

Washington, D.C. 

May 2012 

(Incorporated Change 1, August 24, 2012) 

(Incorporated Change 2, October 12, 2012) 
ii 

CHANGE AND REVIEW LOG

Use this page to record changes and notices of reviews. 

Change 

Number 

Page 

Numbers 

Date Posted 

(mm/dd/yyyy) Initials 

1. G-14 08/24/2012 SJT 

2. 7-1 to 7-3, 7-7 10/12/2012 SJT 

3. 

4. 

5. 

Changes are indicated by a vertical line in the margin next to the change or by shading and 

strikeouts. 

No. Review Date 

(mm/dd/yyyy) 

Comments Initials 

1. 08/24/2012 Corrected Appendix G, Nationally Developed Codes: 

62626 

GBK 

2. 10/12/2012 Updated GEOS References to Reflect Current Status GBK 

3. 

4. 

5. 
1

 Extracted from http://www.ofcm.noaa.gov/ihc12/66IHC-Linking-File.htm, presentations given at the 66th IHC by representatives of the National Hurricane Center, Central Pacific Hurricane 

 Center, and the Joint Typhoon Weather Center. 

2 Extracted from http://www.noaanews.noaa.gov/stories2011/20111128_endofhurricaneseason_2011.html, “Active 2011 hurricane season breaks 'Hurricane Amnesia,' Irene the first hurricane to 

 hit U.S. in three years; Northeast reminded it’s also vulnerable, November 28, 2011 (Updated Jan. 26, 2012).” 3 Extracted from http://www.noaa.gov/extreme2011/irene.html, “NOAA Extreme Weather 2011, “Hurricane Irene – August 20-20, 2011.” 4 Extracted from http://www.noaa.gov/extreme2011/lee.html, NOAA Extreme Weather 2011, “Tropical Strom Lee - Early September 2011.” 

iii 

FOREWORD 

The Office of the Federal Coordinator for Meteorological Services and Supporting Research 

(OFCM) annually hosts the Interdepartmental Hurricane Conference (IHC) to provide a forum 

for the responsible Federal agencies, together with the user communities, such as emergency 

management, to review and improve the Nation's hurricane forecast and warning program. 

 

During the IHC, the OFCM-sponsored Working Group for Hurricane and Winter Storms 

Operations and Research (WG/HWSOR) submitted and reviewed action items related to the 

hurricane program, to include recommended changes to this plan, the National Hurricane 

Operations Plan (NHOP). The 66th IHC was held in Charleston, South Carolina, March 5 - 8, 

2012. New procedures and agreements reached at the conference were incorporated into this 

publication, the 50th edition of the NHOP. This plan is published annually prior to the hurricane 

season and documents the interdepartmental effort to provide the United States and designated 

international recipients with forecasts, warnings, and assessments, concerning tropical and 

subtropical weather systems. 

At the 66th IHC, the WG/HWSOR addressed 20 action items. Of those, seven were closed 

through incorporating changes into this edition of the NHOP, and three items were for 

information only. The remaining 10 items will be worked through follow-on actions by the 

group. Detailed descriptions of the action items are available on the OFCM’s web site at 

http://www.ofcm.noaa.gov/ihc12/action-items.pdf. 

This edition of the NHOP includes a number of revisions and changes to include the continuation 

of last year’s effort to update Chapter 5, Aircraft Reconnaissance. Other noteworthy changes 

include: 

 Revised tropical cyclone names and pronunciations (Tables 3-1 and 3-2). 

 Updated the definition of a subtropical cyclone (Appendix N). 

 Added the term, spiral band, for radar coding on the Vortex Data Message (Table 5-2, 

Item L). 

 Changed the eastern boundary of the 53rd Weather Reconnaissance Squadron’s support 

in the Atlantic Ocean from 55oW to up to 52.5oW, resources permitting (paragraph 

5.5.1.3.1). 

 Removed paragraphs 5.5.4 – 5.5.5.3.4 from Chapter 5, Aircraft Reconnaissance, and 

used them to create a new chapter, Chapter 6, Airspace Operations. As a result, the 

contents of chapters 6-10 were moved to chapters 7-11, respectively. 

The following summarizes the 2011 tropical cyclone season: 

 For the Atlantic hurricane season, there were 19 named tropical storms, of which 7 

became hurricanes and 4 major hurricanes.1

 This year’s totals were above the long-term 
1

 Extracted from http://www.ofcm.noaa.gov/ihc12/66IHC-Linking-File.htm, presentations given at the 66th IHC by representatives of the National Hurricane Center, Central Pacific Hurricane 

 Center, and the Joint Typhoon Weather Center. 

2 Extracted from http://www.noaanews.noaa.gov/stories2011/20111128_endofhurricaneseason_2011.html, “Active 2011 hurricane season breaks 'Hurricane Amnesia,' Irene the first hurricane to 

 hit U.S. in three years; Northeast reminded it’s also vulnerable, November 28, 2011 (Updated Jan. 26, 2012).” 3 Extracted from http://www.noaa.gov/extreme2011/irene.html, “NOAA Extreme Weather 2011, “Hurricane Irene – August 20-20, 2011.” 4 Extracted from http://www.noaa.gov/extreme2011/lee.html, NOAA Extreme Weather 2011, “Tropical Strom Lee - Early September 2011.” 

iv 

averages of 11, 6, and 2 respectively.1 The 19 tropical storms represent the third-highest 

total (tied with 1887, 1995, and 2010) since records began in 1851.2 

 Hurricane Irene, whose name was retired from the Atlantic Basin tropical storm names 

list by the World Meteorological Organization, was the lone hurricane to hit the United 

States in 2011, and the first since Hurricane Ike struck southeast Texas in 2008.2 It was 

also the most significant tropical cyclone to strike the Northeast since Hurricane Bob in 

1991.2 At least 45 deaths and $7.3 billion in damages were attributed to Hurricane Irene, 

and more than 7 million homes and businesses lost power during the storm.3 The 

National Oceanic & Atmospheric Administration’s (NOAA) National Hurricane Center 

(NHC) predicted a North Carolina landfall and a northward path more than four days in 

advance. Additional losses were mitigated by giving emergency officials and the public 

this valuable time to plan evacuations and take safety precautions.3 

 Tropical Storm (TS) Lee shortly followed Hurricane Irene in early September 2011. TS 

Lee produced record flooding across the northeast U.S. with the states of Pennsylvania 

and New York being the most affected.4 Total losses exceeded $1.0 billion and 21 

deaths.4

 For the Eastern North Pacific, there were 11 named storms (below annual average).1 Of 

these, 10 became hurricanes (above average), including 6 major hurricanes (above 

average), resulting in the greatest number of hurricanes since 1998.1 

 The other tropical cyclone basins had the following tropical cyclone activity in 2011 (25-

year averages are noted in parenthesis): Central Pacific - 0 (2); Northwest Pacific - 

27(31); South Pacific and Eastern Australian Region - 9 (10); Arabian Sea and Bay of 

Bengal - 6 (5); and South Indian Ocean and Western Australian Region - 12 (18).1

Both civilian and military organizations comprise the multi-agency national tropical cyclone 

forecasting and warning system. As we strive to be a “Weather-Ready Nation,” the efforts of 

these organizations, along with the reconnaissance aircrews, emergency managers, agency 

leaders, and others help to prevent injuries and the loss of life, reduce vulnerability, and further 

improve weather services to the citizens of this Nation. 

//SIGNED// 

Samuel P. Williamson 

Federal Coordinator for Meteorological 

 Services and Supporting Research
v 

NATIONAL HURRICANE OPERATIONS PLAN

TABLE OF CONTENTS

Page

CHANGE AND REVIEW LOG ................................................................................................. ii 

FOREWORD................................................................................................................................ iii 

TABLE OF CONTENTS ........................................................................................................... v 

CHAPTER 1 INTRODUCTION ......................................................................................... 1-1 

1.1. General ................................................................................................. 1-1 

1.2. Scope .................................................................................................... 1-1 

CHAPTER 2 RESPONSIBILITIES OF COOPERATING FEDERAL 

 AGENCIES..................................................................................................... 2-1 

2.1. General ................................................................................................. 2-1 

2.2. DOC Responsibilities ........................................................................... 2-1 

2.3. DOD Responsibilities ........................................................................... 2-3 

2.4. DOT and DHS Responsibilities ........................................................... 2-4 

2.5. Annual Liaison with Other Nations ..................................................... 2-4 

2.6. Air Traffic Control/Flight Operations Coordination ............................ 2-5 

CHAPTER 3 GENERAL OPERATIONS AND PROCEDURES OF THE NATIONAL 

WEATHER SERVICE HURRICANE CENTERS .................................... 3-1 

3.1. General ................................................................................................. 3-1 

3.2. Products ................................................................................................ 3-1 

3.3. Numbering and Naming of Tropical and Subtropical 

Cyclones ............................................................................................... 3-4 

3.4. Transfer of Warning Responsibility ..................................................... 3-6 

3.5. Alternate Warning Responsibilities ..................................................... 3-6 

3.6. Abbreviated Communications Headings ............................................ 3-10 

3.7. Hurricane Liaison Team (HLT) ......................................................... 3-12 

CHAPTER 4 NATIONAL WEATHER SERVICE PRODUCTS FOR THE 

DEPARTMENT OF DEFENSE ................................................................... 4-1 

4.1. General ................................................................................................. 4-1 

4.2. Observations ......................................................................................... 4-1 

4.3. Tropical Cyclone Forecast/Advisory Content ...................................... 4-1 

CHAPTER 5 AIRCRAFT RECONNAISSANCE .............................................................. 5-1 

5.1. General ................................................................................................. 5-1 

5.2. Responsibilities .................................................................................... 5-1 

5.3. Control of Aircraft ................................................................................ 5-2 

5.4. Reconnaissance Requirements ............................................................. 5-3 

5.5. Reconnaissance Planning and Flight Notification ............................... 5-5 

5.6. Reconnaissance Effectiveness Criteria ............................................... 5-14 
vi 

5.7. Aerial Reconnaissance Weather Encoding, Reporting, 

and Coordination ................................................................................ 5-15 

5.8. Operational Flight Patterns ................................................................. 5-19 

5.9. Aircraft Reconnaissance Communications ........................................ 5-22 

CHAPTER 6 AIRCRAFT OPERATIONS ......................................................................... 6-1

6.1. Pre-mission Coordination ..................................................................... 6-1 

6.2. Mission Execution ................................................................................ 6-4 

CHAPTER 7 SATELLITE SURVEILLANCE OF TROPICAL AND SUBTROPICAL 

CYCLONES ................................................................................................... 7-1 

7.1. Satellites ............................................................................................... 7-1 

7.2. National Weather Service (NWS) Support .......................................... 7-5 

7.3. NESDIS Satellite Analysis Branch (SAB) ........................................... 7-6 

7.4. Air Force Support and the Defense Meteorological 

Satellite Program (DMSP) ................................................................... 7-6 

7.5. Satellites and Satellite Data Availability for the 

Current Hurricane Season .................................................................... 7-7 

7.6. Current Intensity and Tropical Classification Number ........................ 7-7 

 (Incorporated Change 2 – October 12, 2012) 

CHAPTER 8 SURFACE RADAR REPORTING .............................................................. 8-1 

8.1. General ................................................................................................. 8-1 

8.2. The WSR-88D ...................................................................................... 8-1 

8.3. Procedures ............................................................................................ 8-1 

CHAPTER 9 NATIONAL DATA BUOY CAPABILITIES AND 

 REQUIREMENTS......................................................................................... 9-1 

9.1. General ................................................................................................. 9-1 

9.2. Requests for Drifting Buoy Deployment ............................................. 9-2 

9.3. Communications ................................................................................... 9-2 

CHAPTER 10 MARINE WEATHER BROADCASTS .................................................... 10-1 

10.1. General ............................................................................................... 10-1 

10.2. Global Maritime Distress and Safety System 

(GMDSS) ........................................................................................... 10-1 

10.3. Coastal Maritime Safety Broadcasts .................................................. 10-1 

10.4. High Seas Broadcasts ......................................................................... 10-2 

10.5. Additional Information ....................................................................... 10-3 

CHAPTER 11 PUBLICITY ................................................................................................. 11-1 

11.1. News Media Releases ......................................................................... 11-1 

11.2. Distribution ......................................................................................... 11-1 
vii 

APPENDIX A LOCAL NATIONAL WEATHER SERVICE (NWS) 

 OFFICE PRODUCTS ................................................................................... A-1 

APPENDIX B DEFINING POINTS FOR TROPICAL CYCLONE WATCHES/ 

WARNINGS ...................................................................................................B-1 

APPENDIX C JOINT TYPHOON WARNING CENTER (JTWC) BULLETINS ..........C-1 

APPENDIX D FORMAT FOR NHOP/NWSOP FLIGHT INFORMATION FOR 

INTERNATIONAL AND DOMESTIC NOTAM ISSUANCE ................ D-1 

APPENDIX E SAFFIR-SIMPSON HURRICANE WIND SCALE ................................... E-1 

APPENDIX F OFFICIAL INTERAGENCY AGREEMENTS ......................................... F-1 

APPENDIX G RECCO, HDOB, AND TEMP DROP CODES, TABLES, AND 

REGULATIONS ........................................................................................... G-1 

 (Incorporated Change 1 – August 24, 2012) 

APPENDIX H WSR-88D OPERATIONS PLAN FOR TROPICAL CYCLONE 

 EVENTS ....................................................................................................... H-1 

APPENDIX I TELEPHONE LISTING ................................................................................ I-1 

APPENDIX J GEOGRAPHICAL DEFINING POINTS AND PHONETIC 

PRONUNCIATION ........................................................................................ J-1 

APPENDIX K NHOP OPERATIONAL MAPS (TERMINAL AREAS).......................... K-1 

APPENDIX L MISSION COORDINATION SHEET ........................................................ L-1 

APPENDIX M ACRONYMS/ABBREVIATIONS .............................................................. M-1 

APPENDIX N GLOSSARY .................................................................................................. N-1 
viii 

LIST OF FIGURES

Figure Page

1-1. Tropical Cyclone Forecast Centers' Areas of Responsibility ................................. 1-2 

2-1. Super Typhoon Songda, May 27, 2011 .................................................................. 2-1 

4-1. Tropical Cyclone Forecast/Advisory Format .......................................................... 4-4 

4-2. Tropical Cyclone Public Advisory Format ............................................................. 4-5 

5-1. WC-130J Weather Reconnaissance Aircraft .......................................................... 5-2 

5-2. NOAA G-IV and WP-3D Weather Surveillance/Hurricane Aircraft ..................... 5-2 

5-3. Vortex Data Message Worksheet............................................................................ 5-6 

5-4. Example Vortex Data Message (VDM) for the WC-130J ...................................... 5-9 

5-5. NHOP Coordinated Request for Aircraft Reconnaissance ................................... 5-10 

5-6. Tropical Cyclone Plan of the Day Format ............................................................ 5-11 

5-7. Mission Evaluation Form ...................................................................................... 5-17 

5-8. Flight Pattern ALPHA ........................................................................................ 5-20 

5-9. Suggested Patterns for Investigative Missions ..................................................... 5-21 

5-10. Schematic of Aircraft-to-Satellite Data Link for NOAA P-3 Aircraft ................. 5-23 

5-11. Schematic of Aircraft-to-Satellite Data Link for AFRC WC-130 Aircraft .......... 5-24 

7-1. The GOES Satellite System .................................................................................... 7-5 

9-1. Example Buoy and Float Deployment Pattern ........................................................ 9-3 

G-1. Reconnaissance Code Recording Form ................................................................. G-2 

G-2. HDOB Description and Sample Message .............................................................. G-6 

G-3. Example TEMP DROP Message for Tropical Cyclones ..................................... G-15 

K-1. Texas Coast ............................................................................................................ K-1 

K-2. Lake Charles, LA – Pensacola, FL ........................................................................ K-2 

K-3. Pensacola, FL – Tallahassee, FL............................................................................ K-3 

K-4. Central/Southern Florida ........................................................................................ K-4 

K-5. Cuba – Grand Cayman ........................................................................................... K-5 

K-6. The Bahamas: Nassau - Freeport ........................................................................... K-6 

K-7. Turks & Caicos Islands: Grand Turk - Providenciales .......................................... K-7 

K-8. Daytona Beach, FL – Myrtle Beach, SC................................................................ K-8 

K-9. Wilmington, DE – Atlantic City, NJ ...................................................................... K-9 
ix 

LIST OF TABLES

Table Page

3-1. Atlantic Tropical Cyclone Names ........................................................................... 3-7 

3-2. Eastern Pacific Tropical Cyclone Names ............................................................... 3-8 

3-3. Central Pacific Tropical Cyclone Names ................................................................ 3-9 

3-4. International Tropical Cyclone Names for the Northwest Pacific and 

 South China Sea .................................................................................................... 3-10 

3-5. Summary of Products and their Associated WMO Header .................................. 3-11 

5-1. Requirements for Aircraft Reconnaissance Data .................................................... 5-5 

5-2. Vortex Data Message Entry Explanation ................................................................ 5-7 

5-3. Elements of the Mission Identifier ........................................................................ 5-18 

5-4. Examples of Corrected Observations .................................................................... 5-19 

7-1. Communications Headings for SAB Dvorak Analysis Products ............................ 7-6 

7-2. Satellite and Satellite Data Availability for the Current Hurricane Season ............ 7-7 

7-3. The Dvorak Technique: The Empirical Relationship* between the C.I. Number 

 and the Maximum Wind Speed and the Relationship between the T-Number and 

 the Minimum Sea-Level Pressure (SLP) ................................................................ 7-9 

8-1. Participating Radar Stations .................................................................................... 8-2 

G-l. Reconnaissance Code Tables ................................................................................. G-3 

G-2. Reconnaissance Code Regulations ........................................................................ G-5 

G-3. Communications Headers for HDOB Messages.................................................... G-7 

G-4. Mission/Ob Identifier Line Format for HDOB Messages ..................................... G-7 

G-5 HD/HA Data Line Format for HDOB Messages ................................................... G-8 

G-6. TEMP DROP CODE ........................................................................................... G-10 

1-1 

CHAPTER 1

INTRODUCTION

1.1. General. The tropical cyclone warning service is an interdepartmental effort to provide 

the United States and designated international recipients with forecasts, warnings, and 

assessments concerning tropical and subtropical weather systems. The National Oceanic and 

Atmospheric Administration (NOAA) of the Department of Commerce (DOC) is responsible for 

providing forecasts and warnings for the Atlantic and Eastern and Central Pacific Oceans while 

the Department of Defense (DOD) provides the same services for the Western Pacific and Indian 

Ocean (see Figure 1-1). NOAA, along with other Federal agencies such as the U.S. Navy and 

the National Aeronautics and Space Administration (NASA), also conducts supporting research 

efforts to improve tropical cyclone forecasting and warning services. The bottom line—this 

interdepartmental cooperation achieves economy and efficiency in the provision of the tropical 

cyclone forecasting and warning services to the Nation. The National Hurricane Operations 

Plan provides the basis for implementing agreements reached at the Interdepartmental Hurricane 

Conference (IHC), which is sponsored annually by the Office of the Federal Coordinator for 

Meteorological Services and Supporting Research. The goal of the IHC is to bring together the 

responsible Federal agencies to achieve agreement on items of mutual concern related to tropical 

cyclone forecasting and warning services for the Atlantic and Pacific Oceans. 

1.2. Scope. The procedures and agreements contained herein apply to the Atlantic Ocean, 

Gulf of Mexico, Caribbean Sea, and the Pacific Ocean. The plan defines the roles of individual 

agencies, participating in the tropical cyclone forecasting and warning program when more than 

one agency is involved in the delivery of service in any specific area. When a single agency is 

involved in any specific area, that agency's procedures should be contained in internal documents 

and, to the extent possible, be consistent with NHOP practices and procedures. 
1-2 

Figure 1-1. Tropical Cyclone Forecast Centers' Areas of Responsibility
2-1

CHAPTER 2

RESPONSIBILITIES OF COOPERATING FEDERAL AGENCIES

2.1. General. The Department of Commerce (DOC), through the National Oceanic and 

Atmospheric Administration (NOAA), is charged with the overall responsibility to implement a 

responsive, effective national tropical cyclone warning service. Many local, state, and Federal 

agencies play a vital role in this system; their cooperative efforts help ensure that necessary 

preparedness actions are taken to minimize loss of life and destruction of property. The joint 

participation by the Department of Defense (DOD), the Department of Transportation (DOT), 

and the Department of Homeland Security (DHS)/U.S. Coast Guard (USCG) with the DOC 

brings to bear those Federal resources considered essential for storm detection and accurate 

forecasting. This cooperative effort has proven to be a cost-effective, highly responsive 

endeavor to meet national requirements for tropical cyclone warning information. 

Figure 2-1. Super Typhoon Songda, May 27, 2011. 

Credit: DOD/Naval Research Laboratory - Monterey/Marine Meteorology Division 

2.2. DOC Responsibilities. 

 

2.2.1. Forecasting and Warning Services. The DOC will provide timely 

dissemination of forecasts, warnings, and all significant information regarding tropical and 

subtropical cyclones to the appropriate agencies, marine and aviation interests, and the general 

public. 
2-2

2.2.2. Support to DOD. Through NOAA's National Weather Service (NWS), the DOC 

will: 

 Consult, as necessary, with the DOD regarding their day-to-day requirements for 

forecast/advisory services and attempt to meet these requirements within the 

capabilities of the tropical cyclone warning service. 

 Provide, through the National Hurricane Center (NHC), the coordinated DOC 

requirements for weather reconnaissance and other meteorological data to be acquired 

by the DOD on tropical or subtropical cyclones and disturbances. 

 Provide facilities, administrative support, and the means to disseminate 

meteorological data for the Chief, Aerial Reconnaissance Coordination, All 

Hurricanes (CARCAH) as agreed to by the DOC and DOD. 

 Provide the DOD with basic meteorological information, warnings, forecasts, and 

associated prognostic reasoning concerning location, intensity, and forecast 

movement of tropical and subtropical cyclones in the following maritime areas, 

including the adjacent states and possessions of the United States: 

 Atlantic Ocean (north of the equator including the Caribbean Sea and Gulf of 

Mexico). Advisories are the responsibility of the Director, NHC, Miami, FL. The 

NHC will consult with the Fleet Weather Center, Norfolk, VA, prior to issuing 

initial and final advisories and prior to issuing any advisory that indicates a 

significant change in forecast of intensity or track from the previous advisory. 

Exchange of information is encouraged on subsequent warnings when significant 

changes are made or otherwise required. 

 Eastern Pacific Ocean (north of the equator and east of 140°W). Advisories are 

the responsibility of the Director, NHC, Miami, FL. The NHC will consult with 

the Joint Typhoon Warning Center (JTWC), Pearl Harbor, HI, prior to issuing 

initial and final advisories and prior to issuing any advisory that indicates a 

significant change in forecast of intensity or track from the previous advisory. 

Exchange of information is encouraged on subsequent warnings when significant 

changes are made or otherwise required. 

 Central Pacific Ocean (north of the equator between 140°W and 180°). Advisories 

are the responsibility of the Director, Central Pacific Hurricane Center (CPHC), 

Honolulu, HI. In addition to the main Hawaiian Islands, CPHC also issues 

watches and warnings for Johnston Atoll, Midway, and the northwest Hawaiian 

Islands. The CPHC will consult with JTWC prior to issuing initial and final 

advisories and prior to issuing any advisory that indicates a significant change in 

forecast of intensity or track from the previous advisory. Exchange of 

information is encouraged on subsequent warnings when significant changes are 

made or otherwise required. 

 West Pacific Ocean (Guam and Micronesia). Public advisories are prepared by 

the NWS Weather Forecast Office (WFO) Guam, using the tropical cyclone 

forecasts/advisories prepared by JTWC as guidance. WFO Guam issues watches 

and warnings for all tropical cyclones affecting the Territory of Guam, the 

Commonwealth of the Northern Marianas, the Republic of Palau, the Federated 

States of Micronesia, and the Republic of the Marshall Islands. 

 

2.2.3. Post Analysis of Tropical Cyclones. The DOC, through NWS, will conduct an 
2-3

annual post analysis for all tropical cyclones in the Atlantic and the Pacific regions east of 180° 

and prepare an annual hurricane report for issue to interested agencies. 

2.2.4. Environmental Satellite Systems. The National Environmental Satellite, Data, 

and Information Service (NESDIS) will: 

 Operate DOC environmental satellite systems capable of providing coverage of 

meteorological conditions in the tropics during the tropical cyclone season, and 

monitor and interpret DOC satellite imagery. 

 Obtain, as necessary, National Aeronautics and Space Administration (NASA) 

research and development satellite data and Defense Meteorological Satellite 

Program (DMSP) data for NWS operational use and to comply with NHC and CPHC 

satellite data requirements. 

 Provide surveillance support with fixes and/or intensity estimates to the Joint 

Typhoon Warning Center (JTWC), NHC, and CPHC through analysis of all available 

satellite imagery. 

 

2.2.5. Data Buoy Systems. Through the National Data Buoy Center (NDBC), the DOC 

will, subject to available funding, develop, deploy, and operate environmental data buoy systems 

and automated coastal stations to support the data requirements of NHC and CPHC. 

 

2.2.6. Weather Reconnaissance. Through the NOAA Office of Marine and Aviation 

Operations (OMAO), DOC will provide weather reconnaissance flights, including synoptic 

surveillance, as specified in Chapter 5, unless relieved of these responsibilities by the 

Administrator of NOAA. 

2.3. DOD Responsibilities. The DOD will: 

 Disseminate significant meteorological information on tropical and subtropical cyclones to 

the NWS in a timely manner. 

 Provide NHC and CPHC current DOD requirements for tropical and subtropical cyclone 

advisories. 

 Meet DOC requirements for aircraft reconnaissance and other special observations as agreed 

to by DOD and DOC (see Appendix F). 

 Provide at NHC a 24-hour aircraft operations interface—Chief, Aerial Reconnaissance 

Coordination, All Hurricanes (CARCAH). 

 Designate CARCAH as the liaison to NHC. CARCAH will serve as NHC's point of contact 

to request special DOD observations in support of this plan (e.g., additional upper-air 

observations). 

 Provide weather reconnaissance data monitor services to evaluate and disseminate 

reconnaissance reports. 

 Provide surveillance support with fixes and/or intensity estimates to the Central Pacific 

Hurricane Center through analysis of available satellite imagery. The support is provided by 

the 17th Operational Weather Squadron Meteorological Satellite Operations (SATOPS) 

Flight (17 OWS/WXJ), Joint Typhoon Warning Center, Pearl Harbor, HI, and is focused on 

the Indian Ocean and the Central, South, and Northwest Pacific Ocean. 

 Western Pacific Ocean (north of the equator): Provide NWS with basic meteorological 

information, forecasts, and associated prognostic reasoning, concerning location, intensity, 
2-4

wind distribution, and forecast movement of tropical cyclones for the Northwest Pacific west 

of 180o

. JTWC will consult with WFO Guam regarding all tropical cyclones affecting 

Micronesia and Guam. Consultation will occur prior to issuing initial and final advisories 

and prior to issuing any advisory that indicates a significant change in forecast intensity or 

track from the previous advisory. 

 Initiate, monitor, and update satellite invest areas on the tropical cyclone satellite websites 

provided by the Fleet Numerical Meteorology and Oceanography Center (FNMOC) and the 

Naval Research Laboratory (NRL), Monterey, California. NHC and CPHC will coordinate 

with JTWC on the initiation of desired invest areas and will provide JTWC numbers for 

invest areas as required. 

 Deploy, through the Naval Oceanographic Office (NAVOCEANO), drifting data buoys in 

support of the Commander, U.S. Atlantic Fleet (COMLANTFLT) requirements. 

 Consider the Tropical Cyclone Plan of the Day (TCPOD) as a request for assistance (RFA) 

from NOAA. 

 At a minimum, maintain situation awareness of hurricane hunter operational missions 

conducted in applicable combatant command areas of responsibility. 

2.4. DOT and DHS Responsibilities. 

 

2.4.1. Information Dissemination. The DOT will provide NWS with timely 

dissemination of significant information received regarding tropical and subtropical cyclones. 

 

2.4.2. Flight Assistance. Through the Federal Aviation Administration (FAA), the 

DOT will provide air traffic control, communications, and flight assistance services. 

 

2.4.3. U. S. Coast Guard. The Department of Homeland Security (DHS) will provide 

the following through the U.S. Coast Guard: 

 Personnel, vessel, and communications support to the NDBC for development, 

deployment, and operation of moored environmental data buoy systems. 

 Surface observations to NWS from selected coastal facilities and vessels. 

 Communications circuits for relay of weather observations to NWS in selected areas. 

 Coastal broadcast facilities at selected locations for tropical storm or hurricane 

forecasts and warnings. 

2.5. Annual Liaison with Other Nations. 

 

2.5.1. The DOD, DOC, and DOT will cooperate in arranging an annual trip to the 

Caribbean and the Gulf of Mexico area to carry out a continuing and effective liaison with the 

directors of meteorological services, air traffic control agencies, and disaster preparedness 

agencies of nations in those areas, regarding the provision of tropical cyclone warning services. 

Due to the international importance of this mission, the Air Force Reserve Command (AFRC) 

and NHC will jointly plan and execute this mission annually. The NHC will coordinate with the 

meteorological services in the countries to be visited. 

 

2.5.2. This annual liaison trip is known as the Caribbean Hurricane Awareness Tour 

(CHAT). It takes place in the United States Southern and Northern Command’s area of 
2-5

responsibility and supports their mission of promoting stability, collective security, and 

defending U.S. regional interests. The WC-130 aircraft flown by the 53rd Weather 

Reconnaissance Squadron (53rd WRS) “Hurricane Hunters” is the most visible symbol of this 

awareness program; it serves as an educational platform and as a media focus for both dignitaries 

and the local populace. Tours of the aircraft demonstrate the critical partnership between DOD 

and NOAA during the preparation of a tropical cyclone forecast. The CHAT increases public 

awareness of the hurricane threat and serves to recognize and strengthen national and 

international teamwork for storm warning and emergency response. 

 

2.5.3. This diplomatic mission is unique in character and purpose. This joint AFRC and 

NOAA mission demonstrates the concerted U.S. effort to execute its hurricane program and 

illustrates the importance the U.S. places on hurricane forecasting, tracking, and warning. The 

CHAT helps communicate the U.S. responsibilities in the region and it highlights the vital roles 

of NOAA and 53rd WRS. The media’s role is to document the trip and promote the hurricane 

preparedness message, thus providing visibility to this important outreach activity both 

nationally and internationally. 

 

2.5.4. The synergy created by all participants traveling together on the 53rd WRS WC130 aircraft is essential to efficiently accomplishing the overall objectives of the mission while 

exercising fiscal responsibility. AFRC will fly the mission and issue invitational travel orders 

(ITO) on a noninterference, non-reimbursable basis for: the Director of the National Hurricane 

Center (NHC) of the National Weather Service (NWS) National Oceanic and Atmospheric 

Administration (NOAA), U.S. Department of Commerce (DOC); the NHC Hurricane Warning 

Program staff, NWS staff, other U.S. officials, and the media. 

2.6. Air Traffic Control/Flight Operations Coordination. The operations officers of the 

principal flying units, the Manager, Air Traffic Control System Command Center (ATCSCC), 

Warrenton, VA, and the assistant managers for traffic management or assistant manager for 

military operations, as appropriate, at key Air Route Traffic Control Centers (ARTCC) will 

maintain a close working relationship on a continuing basis to ensure mission success under 

actual tropical storm conditions. This will involve visits to each other's facilities, familiarization 

flights, and telephone and electronic communications to improve the understanding of each 

other's requirements and capabilities. 

 

2.6.1. Gulf of Mexico Weather Reconnaissance. The 53rd Weather Reconnaissance 

Squadron and the NOAA Aircraft Operations Center operations officers will maintain a close 

working relationship with the ATCSCC, the ARTCCs, and the Fleet Aerial Control and 

Surveillance Facility (FACSFAC) for the coordination of weather reconnaissance flights in the 

Gulf of Mexico and over the Caribbean Sea in particular, and in the United States in general. 

The operations officers will: 

 Request the assistance of the appropriate ARTCC/FACSFAC in support of the 

National Hurricane Operations Plan. 

 Provide the current operations officer's name and telephone number to the appropriate 

ARTCC and FACSFAC. 

 Publish the unit's telephone numbers [Defense Switched Network 

(DSN)/Commercial]). 
2-6

2.6.2. Air Traffic Control Assistance. The ATCSCC, appropriate ARTCCs, and 

FACSFAC will maintain a close working relationship with the weather reconnaissance units and 

provide airspace and air traffic control assistance to the extent possible. Those organizations 

will: 

 Provide the current names and telephone numbers of points of contact to the flying 

units. 

 Publish telephone numbers (DSN/Commercial). 
3-1 

CHAPTER 3 

GENERAL OPERATIONS AND PROCEDURES OF THE 

NATIONAL WEATHER SERVICE HURRICANE CENTERS

3.1. General. This chapter briefly describes the products, procedures, and communications 

headers used by the National Hurricane Center (NHC) and the Central Pacific Hurricane Center 

(CPHC). See Appendix A for a description of local National Weather Service (NWS) office 

products which support the tropical cyclone forecasting and warning program. Additional details 

of the products, including transmission times, can be found in National Weather Service 

Instruction 10-601, located at: http://www.weather.gov/directives. 

3.2. Products. 

 3.2.1. Tropical Weather Outlook (TWO). NHC and CPHC prepare the TWO during 

their respective tropical cyclone seasons. The outlook covers tropical and subtropical waters and 

discusses areas of disturbed weather and the potential for tropical cyclone development during 

the next 48 hours. The outlook will mention tropical cyclones and subtropical cyclones, 

including the system's location (in either general terms or map coordinates), status, and change in 

status. 

 3.2.2. Tropical Cyclone Public Advisories (TCP). The TCP is the primary tropical 

cyclone information product issued to the public. The TCP comprises five sections: Summary, 

Watches and Warnings, Discussion and Outlook, Hazards, and Next Advisory. The NHC, the 

CPHC, and WFO Guam issue TCPs. The following pertains to the tropical 

storm/hurricane/typhoon watches and warnings contained in the TCP: 

 NHC. NHC issues tropical storm/hurricane watches/warnings for the Atlantic, 

Pacific, and Gulf of Mexico coasts of the continental United States, the US Virgin 

Islands, and Puerto Rico. NHC issues watches when conditions along the coast are 

possible within 48 hours. NHC issues warnings when conditions along the coast are 

expected within 36 hours. 

[NOTE: Because hurricane preparedness activities become difficult once winds reach 

tropical storm force, NHC issues the hurricane/typhoon watches 48 hours in advance of the 

anticipated onset of tropical-storm-force winds.] 

 CPHC and WFO Guam. CPHC and WFO Guam issues tropical 

storm/hurricane/typhoon watches/warnings for the islands of Hawaii, northwest 

Hawaiian Islands, Johnston Atoll, Guam, Northern Mariana Islands and selected 

points in the Micronesian countries. CPHC and WFO Guam issue watches when 

conditions along the coast are possible within 48 hours. CPHC and WFO Guam issue 

warnings when conditions are expected along the coast within 36 hours.
3-2 

[NOTE: Because hurricane/typhoon preparedness activities become difficult once winds 

reach tropical storm force, CPHC and WFO Guam issue the hurricane/typhoon watches 48 

hours in advance of the anticipated onset of tropical-storm-force winds.] 

Intermediate public advisories will be issued in between scheduled or special advisories when 

watches or warnings are in effect. They will continue to be issued when a tropical storm or 

hurricane is inland, even after coastal watches/warnings have been discontinued. These will 

retain the number of the last advisory they update plus an alphabetic designator (e.g., 

HURRICANE ALLISON INTERMEDIATE ADVISORY NUMBER 20A). 

 

3.2.3. Tropical Cyclone Forecast/Advisories (TCM). NHC and CPHC will prepare TCMs for 

all tropical cyclones within their area of responsibility. See Section 4.3 for content and format of 

the advisories. The TCM provides critical tropical cyclone watch, warning, and forecast 

information for the protection of life and property. 

[Note: In the Western Pacific, tropical cyclone forecasts/advisories are issued by the 

JTWC. Appendix C provides a listing of the abbreviated communications headings and 

titles for JTWC products. Information on the broadcast of tropical cyclone information to 

coastal and high-seas shipping can be found in Chapter 10, Marine Weather Broadcasts.] 

 3.2.4. Tropical Cyclone Discussions (TCD). The TCD is a primary tropical cyclone 

product explaining forecaster’s reasoning behind analysis and the forecast for a tropical cyclone. 

It also provides coordinated 12-, 24-, 36-, 48-, 72-, 96-, and 120-hour tropical cyclone forecast 

positions and maximum sustained wind speed forecasts; other meteorological decisions; and 

plans for watches and warnings. 

 3.2.5. Tropical Cyclone Updates (TCU). TCUs are issued to inform users of 

unexpected changes in a tropical cyclone, such as to convey a significant change in the intensity, 

and/or to alert users a special advisory is about to be issued. The TCU may also be used to 

announce changes to international watches or warnings made by other countries, and to cancel 

U.S. watches or warnings. A TCU should only be used to issue a U.S. watch or warning if that 

TCU precedes a special advisory that will contain the same watch/warning information, and 

indicates the special advisory will be issued shortly. 

When a TCU is issued to change the status of a tropical cyclone (e.g., from a tropical storm to a 

hurricane), or to update storm intensity, location, or motion information, the TCU will include a 

storm summary section identical in format to the storm summary section found in the TCP. A 

TCU may be issued without a storm summary section to provide advance notice that significant 

changes to storm information will be conveyed shortly, either through a subsequent TCU or 

through a Special Advisory. TCUs issued to convey changes to watches or warnings will not 

require a storm summary section. 

 3.2.6. Tropical Cyclone Position Estimates (TCE). This product ensures a continuous 

flow of information regarding the center location of a tropical cyclone when it nears the coast 
3-3 

and thus provides up to date location information to emergency managers and other public 

officials. The TCE is a brief alphanumeric product containing information derived from WSR88D radar or appropriate satellite data about tropical cyclone positions near coasts in 

latitude/longitude coordinates, distance, and direction from a well known point. 

 3.2.7. Graphical Tropical Cyclone Surface Wind Speed Probabilities. This 

graphical product portrays probabilistic surface wind speed information which will help users 

prepare for the potential of tropical storm or hurricane conditions. This product shows 

probabilities for three wind speed thresholds: 34, 50 and 64 knots. It provides cumulative 

probabilities through each 12 hour interval (e.g. 0 -12 hours, 0- 24 hours, etc.) from 0 through 

120 hours. They are available in graphical forms in a static and an animated display. These wind 

speed probabilities are based on the track, intensity, and wind structure uncertainties in the 

official forecasts from the tropical cyclone centers. 

 

3.2.8. Tropical Cyclone Surface Wind Speed Probabilities Text Product (PWS). This 

product portrays probabilistic wind speed information helping users prepare for the potential of 

tropical storm or hurricane conditions. 

The probabilities in this product are statistically based on the errors in the official track and 

intensity forecasts issued during the past five years by NHC and CPHC. Variability in tropical 

cyclone wind structure is also incorporated. New probability values are computed for each new 

official forecast issued by NHC or CPHC. 

The first section of the product provides categorical maximum wind speed (intensity) 

probabilities at standard forecast hours (12, 24, 36, 48, 72, 96, and 120) for various intensity 

stages (dissipated, tropical depression, tropical storm and hurricane) and for the five categories 

on the Saffir-Simpson Hurricane Wind Scale. These probabilities apply to the maximum 

sustained surface wind associated with the cyclone, and not to winds that could occur at specific 

locations. 

Probabilities for specific locations are provided in the second section for sustained wind speeds 

equal to or exceeding three wind speed thresholds: 34, 50 and 64 knots. Two types of 

probability values are provided in this table: individual period and cumulative. Individual period 

probabilities are provided for each of the following time intervals: 0-12 hours, 12-24 hours, 24-

36 hours, 36-48 hours, 48-72 hours, 72-96 hours, and 96-120 hours. These individual period 

probabilities indicate the chance that the particular wind speed will start during each individual 

period at each location. Cumulative probabilities are produced for the following time periods: 

0-12 hours, 0-24 hours, 0-36 hours, 0-48 hours, 0-72 hours, 0-96 hours, and 0-120 hours. These 

cumulative probabilities indicate the overall chance the particular wind speed will occur at each 

location during the period between hour 0 and the forecast hour. 

 3.2.9. Tropical Cyclone Watch Warning Product (TCV). The TCV summarizes all 

new, continued, and cancelled tropical cyclone watches and warnings issued by the NHC for the 

U.S. Atlantic and Gulf coast, southern California coast, Puerto Rico, and U.S. Virgin Islands. 
3-4 

The CPHC will issue a TCV for the main islands of the State of Hawaii. The product is issued 

each time a U. S. tropical cyclone watch and/or warning is issued, continued, or discontinued for 

all Atlantic, portions of the North East Pacific, and the North Central Pacific Ocean basin 

tropical cyclones. 

 3.2.10. Hydrometeorological Prediction Center (HPC) Public Advisories (TCP). The 

National Centers for Environmental Prediction’s HPC issues public advisories after NHC 

discontinues its advisories on subtropical and tropical cyclones that have moved inland in the 

conterminous United States or Mexico, but still pose a threat of heavy rain and flash floods in the 

conterminous United States or Mexico. The last NHC advisory will normally be issued when 

winds in an inland tropical cyclone drop below tropical storm strength, and the tropical 

depression is not forecast to regain tropical storm intensity or re-emerge over water. Therefore 

HPC will only handle tropical depressions or remnants. HPC advisories will terminate when the 

threat of flash flooding has ended. 

 3.2.11. Other Tropical Cyclone Products. Several other tropical cyclone related 

products are issued to support the tropical cyclone forecasting and warning program. Refer to 

NWS Instruction 10-601, located at http://www.weather.gov/directives, for further details on 

these products, which include: 

 Satellite Interpretation Message (SIM). 

 Tropical Weather Discussion (TWD). 

 Tropical Weather Summary (TWS). 

 Tropical Cyclone Summary – Fixes (TCS). 

 Tropical Cyclone Danger Area Graphic 

 Aviation Tropical Cyclone Advisory (TCA) 

 Tropical Cyclone Reports (TCR) 

 Tropical Cyclone Track and Watch/Warning Graphic 

 Cumulative Wind Distribution 

 Tropical Cyclone Surface Wind Field Graphic 

 Maximum Wind Speed Probability Table 

 Tropical Cyclone Storm Surge Probabilities 

3.3. Numbering and Naming of Tropical and Subtropical Cyclones. The hurricane centers 

will number tropical depressions in their areas of responsibility. Depression numbers are always 

spelled out (e.g., "ONE,” "TWO," "THREE," etc.). Depression numbers are assigned to match 

the seasonal cyclone number, even if a previous cyclone has bypassed the depression stage. For 

example, if the first tropical cyclone of the season forms directly as a storm (e.g., a fast-moving 

tropical wave becomes a tropical storm without ever becoming a depression), then the depression 

number "ONE" would simply be skipped and not used until the following year. For ease in 

differentiation, tropical depression numbers shall include the suffix "E" for Eastern Pacific, "C" 

for Central Pacific, or "W" for Western Pacific, after the number. 

In both the Atlantic and Pacific, once the depression has reached tropical storm intensity, it shall 

be named and the depression number dropped. The depression number will not be used again 
3-5 

until the following year. Give tropical cyclones a name in the first advisory after intensifying to 

34 knots (39 mph) or greater. In the Western Pacific, WFO Guam will use the JTWC cyclone 

number for all non-named systems. For RSMC Tokyo named systems, WFO Guam will use the 

RSMC Tokyo name with the associated JTWC number in parentheses. 

The following rules apply for tropical cyclones passing from one basin to another: Retain the 

name if a tropical cyclone passes from one basin into another basin as a tropical cyclone; i.e., 

advisories are continuous. An unnamed tropical depression will also retain its number (e.g. 

Tropical Depression Six-E remains Tropical Depression Six-E) if it crosses into another area of 

responsibility. For unnamed tropical depressions moving from west to east across 180°, CPHC 

will use the associated Joint Typhoon Warning Center’s (JTWC) number and indicate JTWC in 

parentheses following the number. For named systems, CPHC will use the associated RSMC 

Tokyo name and provide the associated JTWC number in parentheses. 

Within a basin, if the remnant of a tropical cyclone redevelops into a tropical cyclone, it is 

assigned its original number or name. If the remnants of a former tropical cyclone regenerate in 

a new basin, the regenerated tropical cyclone will be given a new designation. 

 3.3.1. Atlantic Basin. Depression numbers, ONE, TWO, THREE, will be assigned by 

the NHC after advising the Fleet Weather Center, Norfolk. Annual lists of Atlantic storm names 

are provided in Table 3-1. 

 3.3.2. Pacific East of 140oW. Depression numbers, with the suffix E, e.g., ONE-E, 

TWO-E, THREE-E, will be assigned by the NHC after advising JTWC, Pearl Harbor, HI. The 

assigned identifier shall be retained even if the depression passes into another warning area. 

Annual lists of Eastern Pacific storm names are provided in Table 3-2. 

 3.3.3. Pacific West of 140oW and East of 180o. Depression numbers, with suffix C; 

e.g., ONE-C, TWO-C, THREE-C, will be assigned by the CPHC after advising JTWC. Rotating 

lists of Central Pacific storm names are provided in Table 3-3. 

 3.3.4. Pacific West of 180o and North of 0o. Depression numbers, with suffix W; e.g., 

ONE-W, TWO-W, THREE-W, are assigned by JTWC. Rotating lists of Western Pacific storm 

names are provided in Table 3-4. 

 3.3.5. Subtropical Depressions. A single list of numbers and names will be used for all 

tropical and subtropical cyclones in each basin. Therefore, numbering of subtropical depressions 

will follow the same procedure as tropical depressions. For example, if the first subtropical 

depression follows the first tropical depression, the subtropical depression will be given the 

designation SUBTROPICAL DEPRESSION TWO. If a subtropical depression becomes a 

subtropical storm, it receives the next available name in the tropical cyclone naming sequence. 
3-6 

3.4. Transfer of Warning Responsibility. 

 3.4.1. NHC to CPHC. When a tropical or subtropical cyclone approaches 140oW, the 

coordinated transfer of warning responsibility from NHC to CPHC will be made and the 

appropriate advisory issued. 

 3.4.2. CPHC to JTWC/(RSMC, Tokyo)/WFO Guam. When a tropical or subtropical 

cyclone crosses 180o from east to west, the coordinated transfer of warning responsibility from 

CPHC to JTWC will be made and the appropriate advisory issued. At the same time, the CPHC 

will coordinate with the RSMC, Tokyo and WFO Guam so that they are aware that CPHC will 

be suspending the issuance of advisories. 

 3.4.3. JTWC/RSMC, Tokyo to CPHC. When a tropical or subtropical cyclone crosses 

180o from west to east, the coordinated transfer of warning responsibility from JTWC to CPHC 

will be made. At the same time, the CPHC will coordinate with RSMC, Tokyo so that they are 

aware that CPHC will be assuming the issuance of advisories. 

3.5. Alternate Warning Responsibilities.

 3.5.1. Transfer to Alternate. In the event of impending or actual operational failure of 

a hurricane forecast center, tropical warning responsibilities will be transferred to an alternate 

facility in accordance with existing directives and retained there until resumption of 

responsibility can be made. Alternate facilities are as follows: 

PRIMARY ALTERNATE 

NHC 

Atlantic Basin: National Centers for Environmental 

Prediction Hydrometeorological Prediction Center 

(HPC), Camp Springs, MD 

Eastern Pacific Basin: CPHC 

CPHC NHC 

CARCAH 53rd Weather Reconnaissance Squadron (53 WRS) 

JTWC Fleet Numerical Meteorology and Oceanography Center 

(FLENUMETOCCEN), Monterey, CA 

WFO Guam CPHC 

 3.5.2. Notification. The Fleet Weather Center, Norfolk, and JTWC, Pearl Harbor, will 

be advised by NHC, CARCAH, and CPHC, as appropriate, of impending or actual transfer of 

responsibility by the most rapid means available. JTWC will advise CPHC, NHC, and WFO 

Guam of impending or actual transfer of JTWC responsibilities. In the event of a CARCAH 

operational failure, direct communication is authorized between the 53 WRS and the forecast 

facility. Contact 53 WRS at DSN 597-2409/228-377-2409 or through the Keesler AFB 

Command Post at DSN 597-4181/4330; COM 228-377-4181/4330 (ask for the 53 WRS). 
3-7 

Table 3-1. Atlantic Tropical Cyclone Names 

2012 2013 2014

Name Pronunciation Name Pronunciation Name Pronunciation 

Alberto al-BAIR-toe Andrea AN-dree-uh Arthur AR-thur 

Beryl BER-ril Barry BAIR-ree Bertha BUR-thuh 

Chris kris Chantal shahn-TAHL Cristobal krees-TOH-bahl 

Debby DEH-bee Dorian DOR-ee-an Dolly DAH-lee 

Ernesto er-NES-toh Erin AIR-rin Edouard eh-DWARD 

Florence FLOOR-ence Fernand fair-NAHN Fay fay 

Gordon GOR-duhn Gabrielle ga-bree-ELL Gonzalo gohn- SAH-low 

Helene heh-LEEN Humberto oom-BAIR-toh Hanna HAN-uh 

Isaac EYE-zik Ingrid ING-grid Isaias ees-ah-EE-ahs 

Joyce joyss Jerry JEHR-ee Josephine JOH-seh-feen 

Kirk kurk Karen KAIR-ren Kyle KY-ull 

Leslie LEHZ-lee Lorenzo loh-REN-zoh Laura LOOR-ruh 

Michael MY-kuhl Melissa meh-LIH-suh Marco MAR-koe 

Nadine nay-DEEN Nestor NES-tor Nana NA-na 

Oscar AHS-kur Olga OAL-guh Omar OH-mar 

Patty PAT-ee Pablo PAHB-lo Paulette pawl-LET 

Rafael rah-fah--ELL Rebekah reh-BEH-kuh Rene re-NAY 

Sandy SAN-dee Sebastien suh-BASH-chuhn Sally SAL-ee 

Tony TOH-nee Tanya TAHN-yuh Teddy TEHD-ee 

Valerie VAH-lur-ee Van van Vicky VIH-kee 

William WILL-yum Wendy WEN-dee Wilfred WILL-fred 

 

2015 2016 2017 

Name Pronunciation Name Pronunciation Name Pronunciation 

Ana AH-nah Alex AL-leks Arlene ar-LEEN 

Bill bill Bonnie BAH-nee Bret bret 

Claudette klaw-DET Colin KAH-lihn Cindy SIN-dee 

Danny DAN-ee Danielle dan-YELL Don dahn 

Erika eh-RIH-kuh Earl URR-ull Emily EH-mih-lee 

Fred frehd Fiona fee-OH-nuh Franklin FRANK-lin 

Grace grayss Gaston ga-STAWN Gert gert 

Henri ahn-REE Hermine her-MEEN Harvey HAR-vee 

Ida EYE-duh Ian EE-an Irma ER-mah

Joaquin wah-KEEN Julia JOO-lee-uh Jose ho-ZAY 

Kate kayt Karl KAR-ull Katia KAH-tyah 

Larry LAIR-ree Lisa LEE-suh Lee lee 

Mindy MIN-dee Matthew MATH-yoo Maria ma-REE-ah 

Nicholas NIH-kuh-luss Nicole nih-KOHL Nate nait 

Odette oh-DEHT Otto AHT-toh Ophelia o-FEEL-ya 

Peter PEE-tur Paula PAHL-luh Philippe fee-LEEP 

Rose rohz Richard RIH-churd Rina REE-nuh 

Sam sam Shary SHAHR-ee Sean shawn 

Teresa tuh-REE-suh Tobias toh-BEE-uss Tammy TAM-ee 

Victor VIK-tur Virginie vir-JIN-ee Vince vinss 

Wanda WAHN-duh Walter WALL-tur Whitney WHIT-nee 

[Note: If over 21 tropical cyclones occur in a year, the Greek alphabet will be used 

following the W-named cyclone.]
3-8 

Table 3-2. Eastern Pacific Tropical Cyclone Names 

2012 2013 2014

Name Pronunciation Name Pronunciation Name Pronunciation 

Aletta a-LET-ah ALVIN AL-vin Amanda uh-MAN-duh 

Bud buhd BARBARA BAR-bruh Boris bor-EES 

Carlotta kar-LOT-uh COSME COS-may Cristina kris-TEE-nuh 

Daniel DAN-yuhl DALILA Dah-LY-lah Douglas DUG-luss 

Emilia ee-MILL-ya ERICK EHR-ik Elida ELL-ee-dah 

Fabio FAH-bee-o FLOSSIE FLOSS-ee Fausto FOW-sto 

Gilma GIL-mah GIL gill Genevieve jeh-nuh-VEEV 

Hector HEHK-tor HENRIETTE hen-ree-ETT Hernan her-NAHN 

Ileana ill-ay-AH-nah IVO eye-voh Iselle ee-SELL 

John jahn JULIETTE jew-lee-EHT Julio HOO-lee-o 

Kristy KRIS-tee KIKO KEE-ko Karina kuh-REE-nuh 

Lane layne LORENA low-RAY-na Lowell LO-uhl 

Miriam MEER-yim MANUEL mahn-WELL Marie muh-REE 

Norman NOR-muhn NARDA NAHR-duh Norbert NOR-bert 

Olivia uh-LIV-ee-uh OCTAVE AHK-tayv Odile oh-DEAL 

Paul pall PRISCILLA prih-SIH-luh Polo POH-loh 

Rosa ROH-zuh RAYMOND RAY-mund Rachel RAY-chull 

Sergio SIR-gee-oh SONIA SOHN-yah Simon SY-muhn 

Tara TAIR-uh TICO TEE-koh Trudy TROO-dee 

Vicente vee-CEN-tay VELMA VELL-muh Vance vanss 

Willa WIH-lah WALLIS WAHL-lis Winnie WIN-ee 

Xavier ZAY-vee-ur XINA ZEE-nah Xavier ZAY-vee-ur 

Yolanda yo-LAHN-da YORK york Yolanda yo-LAHN-da 

Zeke zeek ZELDA ZEL-dah Zeke zeek 

 

2015 2016 2017 

Name Pronunciation Name Pronunciation Name Pronunciation 

Andres ahn-DRASE Agatha A-guh-thuh Adrian AY-dree-uhn 

Blanca BLAHN-kah Blas Blahs Beatriz BEE-a-triz 

Carlos KAR-loess Celia SEEL-yuh Calvin KAL-vin 

Dolores deh-LOOR-ess Darby DAR-bee Dora DOR-ruh 

Enrique ahn-REE-kay Estelle eh-STELL Eugene YOU-jeen 

Felicia fa-LEE-sha Frank frank Fernanda fer-NAN-dah 

Guillermo gee-YER-mo Georgette jor-JET Greg greg 

Hilda HILL-duh Howard HOW-urd Hilary HIH-luh-ree 

Ignacio eeg-NAH-see-oh Isis EYE-sis Irwin UR-win 

Jimena he-MAY-na Javier Hahv-YAIR Jova HO-vah 

Kevin KEH-vin Kay Kay Kenneth KEH-neth 

Linda LIHN-duh Lester LESS-tur Lidia LIH-dyah 

Marty MAR-tee Madeline MAD-eh-luhn Max maks 

Nora NOOR-ruh Newton NOO-tuhn Norma NOOR-muh 

Olaf OH-lahf Orlene or-LEEN Otis OH-tis 

Patricia puh-TRIH-shuh Paine payne Pilar Pee-LAHR 

Rick rik Roslyn RAWZ-luhn Ramon rah-MOHN 

Sandra SAN-druh Seymour SEE-mor Selma SELL-mah 

Terry TAIR-ree Tina TEE-nuh Todd tahd 

Vivian VIH-vee-uhn Virgil VUR-jill Veronica vur-RAHN-ih-kuh 

Waldo WAHL-doh Winifred WIN-ih-fred Wiley WY-lee 

Xina ZEE-nah Xavier ZAY-vee-ur Xina ZEE-nah 

York york Yolanda Yo-LAHN-da York york 

Zelda ZEL-dah Zeke zeek Zelda ZEL-dah 
3-9 

Table 3-3. Central Pacific Tropical Cyclone Names 

COLUMN 1 COLUMN 2 

Name Pronunciation Name Pronunciation

AKONI ah-KOH-nee AKA AH-kah 

EMA EH-mah EKEKA eh-KEH-kak 

HONE HOH-neh HENE HEH-neh 

IONA ee-OH-nah IOLANA ee-OH-lah-nah 

KELI KEH-lee KEONI keh-ON-nee 

LALA LAH-lah LINO LEE-noh 

MOKE MOH-keh MELE MEH-leh 

NOLO NOH-loh NONA NOH-nah 

OLANA Oh-LAH-nah OLIWA oh-LEE-vah 

PENA PEH-nah PAMA PAH-mah 

ULANA oo-LAH-nah UPANA oo-PAH-nah 

WALE WAH-leh WENE WEH-neh 

COLUMN 3 COLUMN 4 

Name Pronunciation Name Pronunciation

ALIKA ah-LEE-kah ANA AH-nah

ELE EH-leh ELA EH-lah 

HUKO HOO-koh HALOLA hah-LOH-lah

IOPA ee-OH-pah IUNE ee-OO-neh

KIKA KEE-kah KILO KEE-lo

LANA LAH-nah LOKE LOH-keh

MAKA MAH-kah MALIA mah-LEE-ah

NEKI NEH-kee NIALA nee-AH-lah

OMEKA oh-MEH-kah OHO OH-hoh

PEWA PEH-vah PALI PAH-lee

UNALA oo-NAH-lah ULIKA oo-LEE-kah

WALI WAH-lee WALAKA wah-LAH-kah

[Note: Use Column 1 list of names until exhausted before going to Column 2, etc. All 

letters in the Hawaiian language are pronounced, including double or triple vowels.] 
3-10 

Table 3-4. International Tropical Cyclone Names 

for the Northwest Pacific and South China Sea 

Contributor I II III IV V

NAME NAME NAME NAME NAME

Cambodia Damrey Kong-rey Nakri Krovanh Sarika 

China Longwang Yutu Fengshen Dujuan Haima 

DPR Korea Kirogi Toraji Kalmaegi Maemi Meari 

HK, China Kai-tak Man-yi Fung-wong Choi-wan Ma-on 

Japan Tembin Usagi Kammuri Koppu Tokage 

Lao PDR Bolaven Pabuk Phanfone Ketsana Nock-ten 

Macau Chanchu Wutip Vongfong Parma Muifa 

Malaysia Jelawat Sepat Nuri Melor Merbok 

Micronesia Ewiniar Fitow Sinlaku Nepartak Nanmadol 

Philippines Bilis Danas Hagupit Lupit Talas 

RO Korea Kaemi Nari Changmi Sudal Noru 

Thailand Prapiroon Wipha Mekkhala Nida Kulap 

U.S.A. Maria Francisco Higos Omais Roke 

Viet Nam Saomai Lekima Bavi Conson Sonca 

Cambodia Bopha Krosa Maysak Chanthu Nesat 

China Wukong Haiyan Haishen Dianmu Haitang 

DPR Korea Sonamu Podul Pongsona Mindulle Nalgae 

HK, China Shanshan Lingling Yanyan Tingting Banyan 

Japan Yagi Kajiki Kujira Kompasu Washi 

Lao PDR Xangsane Faxai Chan-hom Namtheun Matsa 

Macau Bebinca Peipan Linfa Malou Sanvu 

Malaysia Rumbia Tapah Nangka Meranti Mawar 

Micronesia Soulik Mitag Soudelor Rananim Guchol 

Philippines Cimaron Hagibis Molave Malakas Talim 

RO Korea Chebi Noguri Koni Megi Nabi 

Thailand Durian Rammasun Morakot Chaba Khanun 

U.S.A. Utor Matmo Etau Aere Vicente 

Viet Nam Trami Halong Vamco Songda Saola 

[NOTE: The official international name list was effective January 1, 2000. Names will be 

assigned in rotation starting with Damrey for the first tropical cyclone of the year 2000 

which is of tropical storm strength or greater. When the last name in column 5 (Saola) is 

used, the sequence will begin again with the first name in column 1.] 

3.6. Abbreviated Communications Headings. Abbreviated communications headings are 

assigned to advisories on tropical and subtropical cyclones and other advisories based on 

depression numbers or storm name and standard communications procedures governed by the 
3-11 

World Meteorological Organization (WMO). An abbreviated heading consists of three groups 

with ONE space between each of the groups. The first group contains a data type indicator (e.g., 

WT for hurricane), a geographical indicator (e.g. NT for Atlantic Basin), and a number. The 

second group contains a location identifier of the message originator (e.g., KNHC for NHC). 

The third group is a date-time group in UTC. An example of a complete header is: WTNT61 

KNHC 180400. Table 3-5 provides the abbreviated communications headings for products 

issued by NHC, CPHC, and WFO Guam. 

Table 3-5. Summary of Products and their Associated WMO Header 

PRODUCT TITLE WMO HEADER 

Tropical Weather Outlook

Atlantic Basin ABNT20 KNHC 

Eastern Pacific ABPZ20 KNHC 

Central Pacific ACPN50 PHFO 

Tropical Weather Discussion

Atlantic Basin AXNT20 KNHC 

Eastern Pacific AXPZ20 KNHC 

Tropical/Subtropical Cyclone Public Advisory

Atlantic Basin WTNT31-35 KNHC 

Eastern Pacific WTPZ31-35 KNHC 

Central Pacific WTPA31-35 PHFO 

Western Pacific WTPQ31-35 PGUM 

Tropical Cyclone Surface Wind Speed Probabilities Text Product

Atlantic Basin FONT11-15 KNHC 

Eastern Pacific FOPZ11-15 KNHC 

Central Pacific FOPA11-15 PHFO 

Tropical/Subtropical Cyclone Forecast/Advisory

Atlantic Basin WTNT21-25 KNHC 

Eastern Pacific WTPZ21-25 KNHC 

Central Pacific WTPA21-25 PHFO 

Tropical Cyclone Discussion

Atlantic Basin WTNT41-45 KNHC 

Eastern Pacific WTPZ41-45 KNHC 

Central Pacific WTPA41-45 PHFO 

Tropical Cyclone Valid Time Event Code Product

Atlantic Basin WTNT81-85 KNHC 

Eastern Pacific WTPZ81-85 KNHC 

Central Pacific WTPA81-85 PHFO 

Tropical Cyclone Position Estimate

Atlantic Basin WTNT51-55 KNHC 

Eastern Pacific WTPZ51-55 KNHC 

Central Pacific WTPA51-55 PHFO 

Western North Pacific WTPQ51-55 PGUM 

Tropical Cyclone Update

Atlantic Basin WTNT61-65 KNHC 

Eastern Pacific WTPZ61-65 KNHC 

Central Pacific WTPA61-65 PHFO 
3-12 

Table 3-5 (continued). Summary of Products and their Associated WMO Header 

PRODUCT TITLE WMO HEADER 

Tropical Weather Summary

Atlantic Basin ABNT30 KNHC 

Eastern Pacific ABPZ30 KNHC 

Central Pacific ACPN60 PHFO 

Tropical Cyclone Position and Intensity from Satellite Data

South Central Pacific 120W TXPS40 PHFO 

North Central Pacific 140W - 180 TXPN40 PHFO 

Satellite Interpretation Message

Hawaiian Islands ATHW40 PHFO 

West Pacific (Guam) ATPQ40 PGUM 

Satellite-Derived Rainfall

Eastern Caribbean TCCA21 KNHC 

Central Caribbean TCCA22 KNHC 

Western Caribbean TCCA23 KNHC 

Aviation Tropical Cyclone Advisory Message

Atlantic Basin FKNT21-25 KNHC 

Eastern Pacific FKPZ21-25 KNHC 

Central Pacific FKPA21-25 PHFO 

Tropical Cyclone Summary - Fixes

South Central Pacific 120W TXPS41-45 PHFO 

North Central Pacific 140W - 180 TXPN41-45 PHFO 

[Note: Refer to Appendix C for abbreviated communications headers and titles for the 

products for which JTWC is responsible.] 

3.7. Hurricane Liaison Team (HLT). The HLT is a Department of Homeland Security’s 

Federal Emergency Management Agency (FEMA)-sponsored team made up of federal, state, and 

local emergency managers who have extensive hurricane operational experience. Team members 

function as a bridge between scientists, meteorologists and the emergency managers who 

respond if the storm threatens the United States or its territories. Team members provide 

immediate and critical storm information to government agency decision makers at all levels to 

help them prepare for their response operations, which may include evacuations, sheltering, and 

mobilizing equipment. State and/or local officials, not the HLT, make decisions concerning 

evacuations. 

 3.7.1. National Weather Service (NWS) Responsibilities. The NWS supports the 

HLT through use of NHC meteorologists, Weather Forecast Office (WFO) personnel (typically 

warning coordination meteorologists and service hydrologists), and River Forecast Center (RFC) 

hydrologists. Eastern and Southern Region Headquarters will maintain a list of their available 

HLT candidates. 

 3.7.2. Activation/Deployment. On June 1st, or earlier if necessary, the NHC Director 

will request that the FEMA activate the HLT by contacting the Disaster Operations Directorate. 

The HLT will remain active throughout the season. When a tropical cyclone in the Atlantic or 

eastern North Pacific basins threatens the United States or its territories, the Director or Deputy 
3-13 

Director of NHC may request NWS meteorological and/or hydrological support by contacting 

the appropriate NWS Regional Director. NWS personnel should deploy to NHC within 24 hours 

of the request for assistance. 

NWS personnel will remain deployed at the HLT until the hurricane threat has passed. 

However, if a significant rainfall threat is expected to persist after landfall, the HLT will remain 

staffed by the FEMA to facilitate coordination with the Hydrometeorological Prediction Center 

(HPC), who will assume briefing responsibilities until the rainfall threat has passed. NHC and 

HPC will coordinate the transfer of briefing responsibilities. During the inland event the HLT 

and HPC will coordinate with the appropriate WFOs and RFCs, and when needed, hydrologists 

from the RFCs will provide hydrological briefings. 

If the HLT is deactivated, the HPC will assume the briefing duties provided the remnants of 

the tropical cyclone remain a threat to inland areas. NHC and HPC will coordinate prior to the 

transfer. During the inland event HPC will coordinate with the appropriate WFOs and RFCs and 

when needed, hydrologists from the RFCs will provide hydrological briefings. 

 3.7.3. Training. Completing NWS/FEMA’s distance learning training module, 

Community Hurricane Preparedness, is required by HLT members. The module can be taken via 

the Internet at: http://meted.ucar.edu/hurrican/chp/index.htm. Other training opportunities are 

strongly encouraged. They are: FEMA’s “Introduction to Hurricane Preparedness” conducted at 

NHC for emergency mangers and NWS personnel, and FEMA’s annual HLT training session 

held at NHC. 

 

3.7.4. Meteorological Duties. The HLT meteorologist will: 

 Establish and maintain contact with the impacted WFOs, RFCs, and the HPC. 

 Facilitate participation of the impacted NWS offices in conference calls, briefings, 

and in preparation and distribution of graphics. 

 Provide meteorological interpretations on NHC advisories, WFO hurricane local 

statements, Hurrevac products, and storm surge forecasts for Federal, state and local 

agencies on request. 

 Provide storm briefings via video/audio teleconferences for Federal, state and local 

organizations. 

 Respond to meteorology-related incoming calls from Federal, state, and local 

emergency managers. Refer callers to the appropriate WFO for responses to localized 

special questions and issues. 

 

3.7.5. Hydrologic Duties. The HLT hydrologist will: 

 Establish and maintain contact with the impacted local WFOs, RFCs, and the HPC. 

 Facilitate participation of the impacted NWS offices in conference calls, briefings, 

and in preparation and distribution of graphics. 

 Provide hydrologic interpretation on NHC advisories, WFO hurricane local 

statements, and WFO and RFC hydrologic products for Federal, state and local 

agencies on request. 

 Provide technical support for RFC lead during hydrologic portion of video 

teleconference. In absence of the RFC, lead the hydrologic portion of the video 
3-14 

teleconference. 

 Respond to hydrology-related incoming calls from Federal, state, and local 

emergency managers. Refer callers to the appropriate WFO for responses to localized 

special questions and issues. 
4-1 

CHAPTER 4 

NATIONAL WEATHER SERVICE 

PRODUCTS FOR THE DEPARTMENT OF DEFENSE

4.1. General. The Department of Defense (DOD) and the Department of Commerce (DOC) 

weather forecasting, reconnaissance, and distribution agencies share technical information and 

some responsibilities. Mutually supportive relationships have developed over the years and have 

resulted in a mutual dependency. Due to the nature and distribution of DOD resources and 

operations, the DOD requires certain meteorological information beyond that available to the 

general public. Accordingly, the DOC provides DOD with special observations and advisories 

on tropical and subtropical storms threatening DOD resources or operations. 

4.2. Observations. The National Hurricane Center (NHC) and Central Pacific Hurricane 

Center (CPHC) will make available to DOD all significant tropical and subtropical cyclone 

observations that they receive. 

4.3. Tropical Cyclone Forecast/Advisories.

4.3.1. General. The NHC and CPHC will provide to DOD forecasts and related 

information for tropical and subtropical weather disturbances of depression intensity or greater. 

Forecasts will include location, movement, intensity, and dimension of the disturbances. 

Tropical cyclone forecast/advisories will be disseminated through the National Weather Service 

(NWS) communications facility at Suitland, MD, to the Weather Product Management and 

Distribution System (WPMDS) at the Air Force Weather Agency (AFWA), Offutt AFB, NE, for 

further relay to DOD agencies. The DOD forecasters, who must give advice concerning an 

imminent operational decision, may contact the appropriate hurricane center forecaster (see 

Chapter 2) when published tropical cyclone forecast/advisories require elaboration. Telephone 

numbers for the hurricane centers are in Appendix I. 

4.3.2. Tropical Cyclone Forecast/Advisory Issue Frequency. The first tropical 

cyclone forecast/advisory will normally be issued when meteorological data indicate that a 

tropical or subtropical cyclone has formed. Subsequent advisories will be issued at 0300, 0900, 

1500, and 2100 UTC from NHC and CPHC. The public advisories issued by the NWS Forecast 

Office (WFO) Guam, are issued 1 hour after the JTWC guidance. Advisories will continue to be 

issued until the system is classified below the depression intensity level. In addition, special 

forecasts will be issued whenever the following criteria are met: 

 A significant change has occurred, requiring the issuance of a revised forecast 

package. 

 Conditions require a hurricane or tropical storm watch or warning to be issued. 

Remarks stating the reason for the special forecast or the relocation will be mandatory 

in all special forecasts or advisories that include a relocated position. 

4.3.3. Tropical Cyclone Forecast/Advisory Content. Tropical cyclone forecast/ 

advisories issued by the NHC and CPHC will contain appropriate information as shown in 
4-2 

Figure 4-1. The forecast will contain 12, 24, 36, 48, 72, 96, and 120-hour tropical cyclone 

forecast positions. A code string is appended at the end of the line "NWS NATIONAL 

HURRICANE CENTER MIAMI FL." This is the Automated Tropical Cyclone Forecasting 

(ATCF) System Storm Identification Character String recognized by the WMO for tracking and 

verification of tropical cyclones. The ATCF <Storm ID> is three spaces after "FL" and uses the 

following format: 

NWS NATIONAL HURRICANE CENTER MIAMI FL BBCCYYYY 

where: 

BB = Ocean Basin 

AL - North Atlantic basin...north of the Equator 

SL - South Atlantic basin...south of the Equator 

EP - North East Pacific basin...eastward of 140oW 

CP - North Central Pacific basin between the Dateline and 140oW 

WP - North West Pacific basin...westward of the Dateline 

IO - North Indian Ocean basin...north of the Equator between 40oE and 100oE 

SH - South Pacific Ocean Basin and South Indian Ocean basin 

CC = Cyclone Number 

Numbers 01 through 49 are reserved for tropical and subtropical cyclones. A 

cyclone number is assigned to each tropical or subtropical cyclone in each basin 

as it develops. The numbers are assigned in chronological order. 

Numbers 50 through 79 are reserved for internal use by operational forecast 

centers. 

Numbers 80 through 89 are reserved for training, exercises and testing. 

Numbers 90 through 99 are reserved for tropical disturbances which have the 

potential to become tropical or subtropical cyclones. Although not required, the 

90’s should be assigned sequentially and reused throughout the calendar year. 

YYYY = Four-digit year 

This is the calendar year for the Northern Hemisphere. For the Southern 

Hemisphere, the year begins July 1, with calendar year plus one. 

[Note: Tropical cyclone public advisories issued by the NHC, CPHC, and WFO Guam will 

contain appropriate information as shown in the example in Figure 4-2.] 

 4.3.3.1. Definition of Wind Radii by Quadrant. The working definition of the 

wind radius for a quadrant is: use the largest radius of that wind speed found in the quadrant. 

Example: NHC's quadrants are defined as NE (0°-90°), SE (90°-180°), SW (180°-270°), and 

NW (270°-360°). Given a maximum 34-knot radius of 150 nautical miles (nm) at 0°, 90 nm at 

120°, and 40 nm at 260°, the following line would be carried in the forecast/advisory: 150NE 

90SE 40SW 150NW. 
4-3 

 4.3.3.2. Numbering of Tropical and Subtropical Cyclone Forecast/ 

Advisories. All tropical cyclone forecast/advisories for each unique system in the Atlantic and 

Pacific will be numbered sequentially beginning with the number 1. Some examples are listed 

below: 

Subtropical Depression ONE Forecast/Advisory Number 1 

Tropical Depression ONE Forecast/Advisory Number 1 

Tropical Depression ONE Forecast/Advisory Number 2 

Tropical Storm Anita Forecast/Advisory Number 3 

Hurricane (Typhoon) Anita Forecast/Advisory Number 4 

Tropical Depression Anita Forecast/Advisory Number 5 
4-4 

Figure 4-1. Tropical Cyclone Forecast/Advisory Format 

[Note: NWS text products are limited to 69 characters per line. For the example above (Figure 4-1), there are 

more than 69 characters on some lines so the example could fit on one page.]

ZCZC MIATCMAT4 ALL 

TTAA00 KNHC DDHHMM 

HURRICANE IKE FORECAST/ADVISORY NUMBER 42 

NWS NATIONAL HURRICANE CENTER MIAMI FL AL092008 

1500 UTC THU SEP 11 2008 

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY... 

A HURRICANE WARNING HAS BEEN ISSUED FROM MORGAN CITY LOUISIANA TO BAFFIN BAY TEXAS. 

A TROPICAL STORM WARNING HAS BEEN ISSUED FROM SOUTH OF BAFFIN BAY TO PORT MANSFIELD TEXAS. 

SUMMARY OF WATCHES AND WARNINGS IN EFFECT... 

A HURRICANE WARNING IS IN EFFECT FOR... 

* MORGAN CITY LOUISIANA TO BAFFIN BAY TEXAS 

A TROPICAL STORM WARNING IS IN EFFECT FOR... 

* EAST OF MORGAN CITY TO THE MISSISSIPPI-ALABAMA BORDER...INCLUDING 

THE CITY OF NEW ORLEANS AND LAKE PONTCHARTRAIN 

* SOUTH OF BAFFIN BAY TO PORT MANSFIELD 

HURRICANE CENTER LOCATED NEAR 25.5N 88.4W AT 11/1500Z 

POSITION ACCURATE WITHIN 10 NM 

PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 290 DEGREES AT 9 KT 

ESTIMATED MINIMUM CENTRAL PRESSURE 945 MB 

MAX SUSTAINED WINDS 85 KT WITH GUSTS TO 105 KT. 

64 KT.......100NE 100SE 30SW 60NW. 

50 KT.......150NE 150SE 90SW 140NW. 

34 KT.......230NE 240SE 150SW 180NW. 

12 FT SEAS..330NE 240SE 240SW 400NW. 

WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL 

MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. 

REPEAT...CENTER LOCATED NEAR 25.5N 88.4W AT 11/1500Z 

AT 11/1200Z CENTER WAS LOCATED NEAR 25.3N 88.0W 

FORECAST VALID 12/0000Z 25.9N 90.0W 

MAX WIND 90 KT...GUSTS 110 KT. 

64 KT...100NE 100SE 30SW 60NW. 

50 KT...150NE 150SE 90SW 140NW. 

34 KT...230NE 240SE 150SW 180NW. 

FORECAST VALID 12/1200Z 26.6N 92.0W 

MAX WIND 95 KT...GUSTS 115 KT. 

64 KT...100NE 100SE 50SW 60NW. 

50 KT...150NE 150SE 90SW 140NW. 

34 KT...230NE 240SE 150SW 180NW. 

FORECAST VALID 13/0000Z 27.8N 94.2W 

MAX WIND 105 KT...GUSTS 130 KT. 

64 KT...100NE 100SE 50SW 60NW. 

50 KT...150NE 150SE 90SW 120NW. 

34 KT...230NE 240SE 150SW 160NW. 

FORECAST VALID 13/1200Z 29.5N 95.9W...INLAND 

MAX WIND 100 KT...GUSTS 120 KT. 

50 KT...120NE 125SE 75SW 90NW. 

34 KT...180NE 240SE 120SW 120NW. 

FORECAST VALID 14/1200Z 34.5N 94.0W...INLAND 

MAX WIND 35 KT...GUSTS 45 KT. 

34 KT... 75NE 75SE 50SW 50NW. 

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 225 NM 

ON DAY 4 AND 300 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY 

OUTLOOK VALID 15/1200Z 38.0N 85.0W...POST-TROP/EXTRATROP 

MAX WIND 25 KT...GUSTS 35 KT. 

OUTLOOK VALID 16/1200Z...ABSORBED 

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 25.5N 88.4W 

NEXT ADVISORY AT 11/2100Z 

$$ 

FORECASTER FRANKLIN 
4-5 

Figure 4-2. Tropical Cyclone Public Advisory Format 

[Note: NWS text products are limited to 69 characters per line. For the example above (Figure 4-2), there are more 

than 69 characters on some lines so the example could fit on one page.]

ZCZC MIATCPAT4 ALL 

TTAA00 KNHC DDHHMM 

BULLETIN 

HURRICANE IKE ADVISORY NUMBER 42 

NWS NATIONAL HURRICANE CENTER MIAMI FL AL092008 

1000 PM CDT THU SEP 11 2008 

...IKE CONTINUES TO GROW IN SIZE BUT HAS NOT STRENGTHENED YET...HURRICANE WARNING ISSUED FOR NORTHWESTERN GULF COAST... 

SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION 

----------------------------------------------- 

LOCATION...25.5N 88.4W 

ABOUT 580 MI...930 KM ESE OF CORPUS CHRISTI TEXAS 

ABOUT 470 MI...760 KM ESE OF GALVESTON TEXAS 

MAXIMUM SUSTAINED WINDS...100 MPH...160 KM/HR 

PRESENT MOVEMENT...WNW OR 290 DEGREES AT 10 MPH...17 KM/HR 

MINIMUM CENTRAL PRESSURE...945 MB...27.91 INCHES 

WATCHES AND WARNINGS 

-------------------- 

CHANGES WITH THIS ADVISORY... 

A HURRICANE WARNING HAS BEEN ISSUED FROM MORGAN CITY LOUISIANA TO BAFFIN BAY TEXAS. 

A TROPICAL STORM WARNING HAS BEEN ISSUED FROM SOUTH OF BAFFIN BAY TO PORT MANSFIELD TEXAS. 

SUMMARY OF WATCHES AND WARNINGS IN EFFECT... 

A HURRICANE WARNING IS IN EFFECT FOR...MORGAN CITY LOUISIANA TO BAFFIN BAY TEXAS 

A TROPICAL STORM WARNING IS IN EFFECT FOR...EAST OF MORGAN CITY TO THE MISSISSIPPI-ALABAMA BORDER...INCLUDING THE CITY OF NEW 

ORLEANS AND LAKE PONTCHARTRAIN SOUTH OF BAFFIN BAY TO PORT MANSFIELD 

A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA. A WARNING IS TYPICALLY 

ISSUED 36 HOURS BEFORE THE ANTICIPATED FIRST OCCURRENCE OF TROPICAL-STORM-FORCE WINDS...CONDITIONS THAT MAKE OUTSIDE PREPARATIONS 

DIFFICULT OR DANGEROUS. PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO COMPLETION. 

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN THE NEXT 

36 HOURS. 

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED BY 

YOUR LOCAL WEATHER OFFICE. 

DISCUSSION AND 48-HOUR OUTLOOK 

------------------------------ 

AT 1000 PM CDT...0300Z...THE CENTER OF HURRICANE IKE WAS LOCATED NEAR LATITUDE 25.5 NORTH...LONGITUDE 88.4 WEST. IKE IS MOVING TOWARD 

THE WEST-NORTHWEST NEAR 10 MPH...17 KM/HR. A GENERAL WEST- NORTHWESTWARD MOTION IS EXPECTED OVER THE NEXT DAY OR SO...AND THE 

CENTER OF IKE SHOULD BE VERY NEAR THE COAST BY LATE FRIDAY. 

MAXIMUM SUSTAINED WINDS ARE NEAR 100 MPH...160 KM/HR...WITH HIGHER GUSTS. IKE IS A CATEGORY TWO HURRICANE ON THE SAFFIR-SIMPSON 

SCALE. IKE IS FORECAST TO BECOME A MAJOR HURRICANE PRIOR TO REACHING THE COASTLINE. 

IKE REMAINS A VERY LARGE TROPICAL CYCLONE. HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 115 MILES...185 KM...FROM THE CENTER...AND 

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 275 MILES...445 KM. 

THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY A NOAA HURRICANE HUNTER AIRCRAFT WAS 945 MB...27.91 INCHES. 

HAZARDS AFFECTING LAND 

---------------------- 

STORM SURGE...STORM SURGE WILL RAISE WATER LEVELS AS MUCH AS 10 TO 15 FT ABOVE GROUND LEVEL ALONG THE COAST WITHIN THE HURRICANE 

WARNING AREA...WITH LARGE AND DANGEROUS BATTERING WAVES...NEAR AND TO THE EAST OF WHERE THE CENTER OF IKE MAKES LANDFALL. STORM 

SURGE WILL RAISE WATER LEVELS AS MUCH AS 5 TO 7 FEET ABOVE GROUND LEVEL ALONG THE COAST WITHIN THE TROPICAL STORM WARNING AREA 

ALONG THE NORTHERN GULF COAST. THE SURGE COULD PENETRATE AS FAR INLAND AS ABOUT 10 MILES FROM THE SHORE WITH DEPTH GRADUALLY 

DECREASING AS THE WATER MOVES INLAND. 

WIND...BECAUSE IKE IS A VERY LARGE TROPICAL CYCLONE...WEATHER WILL DETERIORATE ALONG THE COASTLINE LONG BEFORE THE CENTER REACHES 

THE COAST. HURRICANE CONDITIONS ARE EXPECTED TO REACH NORTHWESTERN GULF COAST WITHIN THE WARNING AREA FRIDAY AFTERNOON. 

WINDS ARE EXPECTED TO FIRST REACH TROPICAL STORM STRENGTH FRIDAY MORNING...MAKING OUTSIDE PREPARATIONS DIFFICULT OR DANGEROUS. 

PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO COMPLETION. 

RAINFALL...IKE IS EXPECTED TO PRODUCE RAINFALL AMOUNTS OF 5 TO 10 INCHES ALONG THE CENTRAL AND UPPER TEXAS COAST AND OVER PORTIONS 

OF SOUTHWESTERN LOUISIANA...WITH ISOLATED MAXIMUM AMOUNTS OF 15 INCHES POSSIBLE. RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE

OVER PORTIONS OF THE YUCATAN PENINSULA. 

NEXT ADVISORY 

-------------- 

NEXT INTERMEDIATE ADVISORY...100 AM CDT. 

NEXT COMPLETE ADVISORY...400 AM CDT. 

$$ 

FORECASTER FRANKLIN 

NNNN 

5-1 

CHAPTER 5 

AIRCRAFT RECONNAISSANCE

5.1. General. All Department of Commerce (DOC) tropical and subtropical cyclone aircraft 

reconnaissance needs will be requested and provided in accordance with the procedures of this 

chapter. As outlined in the Air Force Reserve Command (AFRC)/National Oceanic and 

Atmospheric Administration (NOAA) Memorandum of Agreement (see Appendix F), DOC has 

identified a requirement for, and the Department of Defense (DOD) maintains aircraft to support, 

up to five sorties per day. Requirements exceeding five sorties will be accomplished on a 

"resources-permitting" basis. In times of national emergency or war, some or all DOD 

reconnaissance resources may not be available to fulfill DOC needs. The Global Decision 

Support System (GDSS) JCS Priority Code for tasked, operational weather reconnaissance is 

1A3 (IAW DOD Regulation 4500.9-R and Joint Publications 4-01 and 4-04). The Force Activity 

Designator (FAD)/Urgency of Need Designator (UND) Supply Priority Designator 

Determination code is IIA2 (IAW Joint Publication 4-01 and Air Force Manual 23-110, Volume 

2, Part 13, Attachment 3A-2.) 

5.2. Responsibilities. The DOD, through the AFRC's 53rd Weather Reconnaissance 

Squadron (53 WRS), and DOC, through NOAA's Aircraft Operations Center (AOC), operate a 

complementary fleet of aircraft to conduct hurricane/tropical cyclone reconnaissance, synoptic 

surveillance, and research missions. 

5.2.1. DOD. The DOD is responsible for: 

5.2.1.1. Providing operational aircraft for vortex fixes and data, synoptic 

surveillance missions, and investigative flights in response to DOC needs (see Figure 5-1). 

5.2.1.2. Developing operational procedures and deploying data buoys to satisfy 

DOC needs. 

5.2.2. DOC. The DOC is responsible for aircraft operations that may be requested to: 

5.2.2.1. Provide synoptic surveillance soundings (see Figure 5-2). 

5.2.2.2. Augment AFRC aircraft reconnaissance when DOC needs exceed the 

capabilities of DOD resources (see Figure 5-2). 

5.2.2.3. Assume responsibility for hurricane reconnaissance over foreign airspace 

that may be restricted for military operations. 

5.2.2.4. Conduct research flights. 

5.2.3. DOT. The DOT is responsible for providing air traffic control services to aircraft 

when within airspace controlled by the FAA. This includes offshore oceanic airspace. Procedures 
5-2 

for the expeditious handling of reconnaissance aircraft are documented in chapter 6, Airspace 

Operations. 

Figure 5-1. WC-130J Weather Reconnaissance Aircraft 

Figure 5-2. NOAA G-IV and WP-3D Weather Surveillance/Hurricane Aircraft 

5.3. Control of Aircraft. Operational control of aircraft flying tropical and subtropical 

cyclone reconnaissance will remain with the operating agencies which own the aircraft. 

 
5-3 

5.4. Reconnaissance Requirements.

5.4.1. Meteorological Parameters. Data needs in priority order are as follows: 

 Geographical position of the flight level vortex center (vortex fix) and relative 

position of the surface center, if known. 

 Center sea-level pressure determined by dropsonde or extrapolation from within 

1,500 ft of the sea surface or from the computed 925 hPa, 850 hPa, or 700 hPa height. 

 Minimum 700, 850 or 925 hPa height, if available. 

 Wind data (continuous observations along the flight track) for surface and flight level. 

 SFMR surface wind. 

 High density three-dimensional Doppler radial velocities of the tropical cyclone core 

circulation. 

 Temperature at flight level. 

 SFMR rain rate. 

 Sea-surface temperature. 

 Dew-point temperature at flight level. 

 

5.4.2. Accuracy.

 

5.4.2.1. Geographic Position.

 Aircraft position: within 3 nm. 

 Storm surface center (wind/pressure): within 6 nm. 

 Flight level storm center (wind/pressure): within 6 nm. 

 

5.4.2.2. Wind Direction.

 Surface: within 10 deg. 

 Flight level for winds greater than 20 kt: within 5 deg. 

 

5.4.2.3. Wind Speed.

 Surface: within 10 kt. 

 Flight level: within 4 kt. 

 

5.4.2.4. Pressure Height.

 Surface: within 2 hPa. 

 Flight level at or below 500 hPa: within 10 m. 

 Flight level above 500 hPa: within 20 m. 

 

5.4.2.5. Temperature.

 Sea surface: within loC. 

 Flight level: within loC. 

 

5.4.2.6. Dew-Point Temperature.

 From -20oC to +40°C: within loC. 

 Less than -20oC: within 3oC. 
5-4 

 5.4.2.7. Absolute Altitude: Within 10 m. 

 5.4.2.8. Vertical Sounding.

 Pressure: within 2 hPa. 

 Temperature: within 1oC. 

 Dew-point temperature: 

 From -20oC to +40oC: within loC. 

 Less than -20oC: within 3oC. 

 Wind direction: within 10 deg. 

 Wind speed: within 5 kt. 

 

5.4.2.9. Core Doppler Radar. 

 Horizontal resolution along aircraft track: 1.5 km 

 Radar beam width: 3 degrees. 

 Radar radial resolution (gate length): 150 m. 

 Error in radar radial velocity: 1 m/s. 

 Range: 50 km.

[NOTE: Present weather reconnaissance capabilities do not completely satisfy these 

requirements; data will be collected as close to stated requirements as possible.] 

5.4.3. High-Density/High-Accuracy (HD/HA) Data Requirements. The HD/HA data 

include UTC time, aircraft latitude, longitude, static pressure, geopotential height, extrapolated 

sea level pressure or D-Value, air temperature, dew point temperature, flight-level (FL) wind 

direction, FL wind speed, peak 10-second (10-s) average FL wind speed, peak 10-s average 

surface wind speed from the stepped frequency microwave radiometer (SFMR), SFMR-derived 

rain rate, and quality control flags. Except for the peak values noted above, all data provided in 

HDOB messages are 30-second averages, regardless of the interval at which the HDOB 

messages are reported. See Appendix G for HDOB message formats. The DOC requires rapid 

acquisition and transmission of tropical cyclone data, especially within the 24-hour period prior 

to landfall. If HD/HA capability is lost on an operational mission, the airborne meteorologist will 

immediately contact Chief, Aerial Reconnaissance Coordination, All Hurricanes (CARCAH) to 

determine data requirements for the remainder of the mission. 

5.4.4. Synoptic Surveillance Data Requirements. When required, NHC will request 

sounding data on the periphery of systems approaching the United States. NHC will provide 

specific tracks including control points, control times and dropwindsonde frequency allocations 

to CARCAH for coordination with the reconnaissance units. 

5.4.5. Core Doppler Radar Requirements. When required, NHC and the 

Environmental Modeling Center (EMC) will coordinate to request high-density threedimensional Doppler radial velocities in the tropical cyclone core for potential storms impacting 

the United States, including Puerto Rico and the Virgin Islands. EMC, NHC, and HRD will 

coordinate to provide specific flight plans to CARCAH for coordination with the reconnaissance 

units. 
5-5 

5.4.6. Required Frequency and Content of Observations. Observation requirements 

are summarized in Table 5-1. Deviations to these requirements will be coordinated through 

CARCAH. The Vortex message format and information are shown in Figure 5-3, Figure 5-4, and 

Table 5-2. Other data message formats and code breakdowns can be found in Appendix G. 

Table 5-1. Requirements for Aircraft Reconnaissance Data

RECCO Section 1 

plus 4ddff and 9VTTT 

as applicable

Vortex Data 

Message 

(VDM)

Vertical Data 

WMO Temp 

Drop Code 

(FM37-VII)

High Density 

Observation 

(HDOB)

En route

Approx. every 30 

minutes over water not 

to exceed 200 nm

NA

Approx every 400 

nm over water, or 

fewer/relocated per 

request or sonde 

conservation 

30-sec interval 

Invest 

area

At major turn turnpoints. 

Also, every 15 minutes if 

HDOBs are INOP.

After closing a 

circulation NA 30-sec interval 

Fix 

pattern

End points of Alpha 

pattern legs. 

When necessary with 

radar fix information.

Each fix. 

Each tasked fix at 

or above 850 mb. 

Intermediate fixes 

and eyewall 

modules as 

requested.

30-sec interval 

5.4.7. WP-3D Configuration. The minimum operational configuration of the WP-3D 

will include the stepped frequency microwave radiometer (SFMR), Doppler radar and the 

advanced vertical atmospheric profiling system (AVAPS).

5.5. Reconnaissance Planning and Flight Notification.

5.5.1. DOC Requests for Aircraft Reconnaissance Data.

5.5.1.1. Coordination. Any agency requesting aircraft reconnaissance (e.g., 

the NWS Environmental Modeling Center (EMC), the Central Pacific Hurricane Center (CPHC)) 

should contact the National Hurricane Center (NHC) no later than 1630 UTC the day prior to the 

requirement, and within the constraints of paragraph 5.5.2.1. NHC will compile the list of the 

total DOC requirements for data on tropical and subtropical cyclones or disturbances for the next 

24-hour period (1100 to 1100 UTC) and an outlook for the succeeding 24-hour period. This 

coordinated request will be considered the agency’s request for assistance (RFA) to DOD and 

will be provided to CARCAH as soon as possible, but no later than 1630 UTC each day in the 

format of Figure 5-5. 

5.5.1.2. Tropical Cyclone Plan of the Day. From the coordinated DOC 

request, CARCAH will publish the Tropical Cyclone Plan of the Day (TCPOD). The format for 

the TCPOD is shown in Figure 5-6. When DOC reconnaissance needs exceed DOD and DOC 

resources, CARCAH will coordinate with the NHC to establish priorities of requirements. 
5-6 

DATE SCHEDULED FIX 

TIME 

AIRCRAFT 

NUMBER ARWO 

WX MISSION IDENTIFICATION STORM NUMBER IDENTIFIER OB 

VORTEX DATA MESSAGE 

A DATE AND TIME OF FIX 

B 

 DEG MIN N S LATITUDE OF VORTEX FIX 

 DEG MIN E W LONGITUDE OF VORTEX FIX 

C MINIMUM HEIGHT AT STANDARD LEVEL 

D ESTIMATE OF MAXIMUM SURFACE WIND OBSERVED 

E BEARING AND RANGE FROM CENTER OF MAXIMUM SURFACE WIND 

F MAXIMUM FLIGHT LEVEL WIND NEAR CENTER 

G BEARING AND RANGE FROM CENTER OF MAXIMUM FLIGHT LEVEL WIND 

H 

 MINIMUM SEA LEVEL PRESSURE COMPUTED FROM DROPSONDE OR 

EXTRAPOLATED FROM FLIGHT LEVEL. IF EXTRAPOLATED, CLARIFY IN 

REMARKS. 

I MAXIMUM FLIGHT LEVEL TEMP/PRESSURE ALTITUDE OUTSIDE EYE 

J MAXIMUM FLIGHT LEVEL TEMP/PRESSURE ALTITUDE INSIDE EYE 

K DEWPOINT TEMP/SEA SURFACE TEMP INSIDE EYE 

L EYE CHARACTER: Closed wall, poorly defined, open SW, etc. 

M 

 EYE SHAPE/ORIENTATION/DIAMETER. CODE EYE SHAPE AS: C -Circular; 

CO - Concentric; E- Elliptical. TRANSMIT ORIENTATION OF MAJOR AXIS IN 

TENS OF DEGREE (i.e., 01-010 to 190; 17-170 to 350). TRANSMIT DIAMETER 

IN NAUTICAL MILES. Examples: C8 - Circular eye 8 miles in diameter. 

EO9/15/5 - Elliptical eye, major axis 090-270, length of major axis 15 NM, length 

of minor axis 5NM. CO8-14 - Concentric eye, diameter inner eye 8 NM, outer eye 

14 NM. 

N 

 FIX DETERMINED BY/FIX LEVEL. FIX DETERMINED BY: 1 - Penetration; 2 - 

Radar; 3 - Wind; 4 - Pressure; 5 - Temperature. FIX LEVEL: Indicate surface 

center if visible; indicate both surface and flight level centers only when same: 0 - 

Surface; 1 - 1500ft; 9-925mb; 8 - 850 mb; 7 - 700 mb; 5 - 500 mb; 4 - 400 mb; 3 - 

300 mb; 2 - 200 mb; NA - Other. 

O NAVIGATION FIX ACCURACY/METEOROLOGICAL ACCURACY 

P 

REMARKS 

 MAX FL WIND_________________KT_________QUAD_________________________Z 

 MAX OUTBOUND FL WIND_________________KT_________QUAD______________Z 

 SLP EXTRAP FROM (Below 1500 FT/ 925 MB/ 850 MB/ DROPSONDE) 

 SFC CNTR__________________________/______________NM FROM FL CNTR 

 MAX FL TEMP _________C___________/___________NM FROM FL CNTR 

 SURFACE WIND OBSERVED VISUALLY 

INSTRUCTIONS: Items A through G (and H when extrapolated) are transmitted from the aircraft immediately 

following the fix. The remainder of the message is transmitted as soon as available. 

Figure 5-3. Vortex Data Message Worksheet
5-7 

Table 5-2. Vortex Data Message Entry Explanation 

DATA ITEM ENTRY

Mission Identifier As determined in Chapter 5, paragraph 5.7.6. 

Storm Identifier As determined in Chapter 4, paragraph 4.3.3. 

Observation Number A two digit number determined by the sequential order in which the observation is 

transmitted from the aircraft. 

A (ALPHA) Date and time (UTC) of the flight level center fix. If the flight level center cannot be 

fixed and the surface center is visible, enter the time of the surface center fix. 

B (BRAVO) The latitude and longitude of the center fix associated with item ALPHA. NOTE: If the 

surface center is fixable, enter bearing and range from the FL center in Remarks; e.g., 

SFC CNTR 270/15 nm, if the centers are separated by over 5 nm. 

C (CHARLIE) Indicate the standard atmospheric surface e.g. 925, 850 or 700 hPa. The minimum height 

of the standard surface observed inside the center. If at 1,500 ft or below or not within 

1,500 ft of a standard surface, enter NA. 

D (DELTA) The maximum surface wind observed during the inbound leg associated with this fix. 

When SFMR surface wind data are unavailable, the surface wind is determined visually. 

E (ECHO) Bearing and range of the maximum surface wind observed (item DELTA) from the 

coordinates reported in item BRAVO. 

F (FOXTROT) The maximum flight level wind observed during the inbound leg associated with this fix. 

If a significant secondary maximum wind is observed, report it in remarks. All winds 

reported should be 10-s averages. 

G (GOLF) Bearing and range of the maximum flight level wind observed (item FOXTROT) from the 

coordinates reported in item BRAVO. 

H (HOTEL) The minimum sea level pressure (SLP) to the nearest hectopascal observed at the 

coordinates reported in item BRAVO. Preface the SLP with "EXTRAP" (extrapolated) 

when the data are not derived from dropsonde or when the SLP is extrapolated from a 

dropsonde that terminated early. Clarify the difference in remarks (e.g., SLP 

EXTRAPOLATED FROM BELOW 1500 FEET/850 HPA/DROPSONDE). 

I (INDIA) MAX FLT LVL TEMP--This temperature is taken just outside the central region of a 

cyclone (i.e., just outside the eyewall or just beyond the maximum wind band). This 

temperature may not be the highest recorded on the inbound leg but is representative of 

the environmental temperature just outside the central region of the storm. 

PRESSURE ALT--Pressure altitude data (meters) are taken at the same location as the 

maximum temperature data reported in item INDIA. 
5-8 

Table 5-2 (continued). Vortex Data Message Entry Explanation 

DATA ITEM ENTRY

J (JULIET) MAX FLT LVL TEMP--The maximum temperature observed within 5 nm of the center 

fix coordinates. If a higher temperature is observed at a location more than 5 nm away 

from the flight level center (item BRAVO), it is reported in Remarks, including bearing 

and distance from the flight level center. 

PRESSURE ALT--Pressure altitude data (meters) are taken at the same location as the 

maximum temperature data reported in item JULIET.

K (KILO) Dewpoint temperature/sea surface temperatures are collected at the same location as the 

maximum temperature reported in item JULIET. Enter NA if not observed. 

L (LIMA) Only report if at least 50 percent of the center has an eyewall, otherwise enter NA. 

Closed wall--if the center has 100 percent coverage with no eyewall weakness. 

Open XX--if the center has 50 percent or more but less than 100 percent coverage. State 

the direction of the eyewall weakness. 

Spiral band--report Item Juliet with the best approximation of the shape and diameter of 

the inner core. 

M (MIKE) Self explanatory. Report only if item LIMA is reported, otherwise enter NA. 

N (NOVEMBER) Fix determined by: Always report 1. Report 2 if radar indicates curvature or banding 

consistent with fix location. Report 3 if recorded or observed winds indicate a closed 

center. Report 4 if the fix pressure is lower than all reported on the inbound leg. Report 5 

if the fix temperature is at least higher than any reported on the inbound leg. 

Fix level: Report 0 alone if fix is made solely on surface winds. Report 0 and the 

flight-level code if the centers are within 5 nm of each other. 

O (OSCAR) Navigational and meteorological accuracy are reported as the upper limit of probable 

error. Meteorological accuracy is normally reported as one-half of the diameter of the 

light and variable wind center. 

P (PAPA) Remarks to enhance the data reported above. Required remarks include: (1) mission 

identifier and observation number; (2) the maximum flight level wind observed, time of 

observation, and the relative quadrant of the storm of the observed wind on the latest pass 

through any portion of the storm; (3) the maximum flight-level wind observed on the 

outbound leg following the center fix just obtained, if it is higher than the inbound 

maximum reported in item F. Include time of observation and the relative quadrant of the 

storm of the qualifying outbound max wind. If, after the transmission of the vortex 

message but prior to the aircraft reaching the cross-leg turn point, a higher qualifying 

outbound wind is observed, then the vortex message will be amended with the higher 

outbound wind reported. If the outbound max FL wind becomes the new overall max FL 

wind, then consolidate the two max FL wind remarks into one remark; (4) the method of 

deriving the central SLP when extrapolated; and (5) the bearing and range of the surface 

center and/or maximum flight level temperature if not within 5 nm of the flight level 

center. 
5-9 

Figure 5-4. Example Vortex Data Message (VDM) for the WC-130J 

 

URNT12 KNHC 072030 

VORTEX DATA MESSAGE AL092008 

A. 07/20:09:20Z 

B. 21 deg 01 min N 

 074 deg 26 min W 

C. 700 mb 2624 m 

D. 90 kt 

E. 045 deg 13 nm 

F. 147 deg 106 kt 

G. 047 deg 016 nm 

H. 945 mb 

I. 10 C/ 3045 m 

J. 16 C/ 3057 m 

K. 13 C/ NA 

L. CLOSED WALL 

M. CO16-48 

N. 12345/7 

O. 0.02 / 1 nm 

P. AF307 0909A IKE OB 11 

MAX FL WIND 107 KT NW QUAD 18:21:10 Z 
5-10 

NHOP COORDINATED REQUEST FOR AIRCRAFT RECONNAISSANCE

___ Original 

___ Amendment 

 (Check One) 

 I. ATLANTIC REQUIREMENTS 

 STORM NAME FIX OR ON 

 DEPRESSION # STATION FLIGHT FCST NHC 

 SUSPECT AREA TIME COORDINATES PATTERN MVMT PRIORITY 

 ___________________________________________________________________________________________________ 

 ___________________________________________________________________________________________________ 

 ___________________________________________________________________________________________________ 

 GULF STREAM _____________________________________________________________________________________ 

 SUCCEEDING DAY OUTLOOK _______________________________________________________________________ 

 ___________________________________________________________________________________________________ 

 REMARKS _________________________________________________________________________________________ 

 ___________________________________________________________________________________________________ 

 II. PACIFIC REQUIREMENTS 

 STORM NAME FIX OR ON 

 DEPRESSION # STATION FLIGHT FCST NHC 

 SUSPECT AREA TIME COORDINATES PATTERN MVMT PRIORITY 

 ___________________________________________________________________________________________________ 

 ___________________________________________________________________________________________________ 

 ___________________________________________________________________________________________________ 

 SUCCEEDING DAY OUTLOOK _______________________________________________________________________ 

 ___________________________________________________________________________________________________ 

 REMARKS _________________________________________________________________________________________ 

 ___________________________________________________________________________________________________ 

 III. DISTRIBUTION 

 A. TO CARCAH BY 1630Z OR AMEND AT ANY TIME 

 B. Date ___________ Time _________ FCSTR INITIAL __________ 

 C. 53 WRS ________ AOC _________ Other __________ 

 Figure 5-5. NHOP Coordinated Request for Aircraft Reconnaissance 
5-11 

TROPICAL CYCLONE PLAN OF THE DAY FORMAT 

ATLANTIC AND CENTRAL PACIFIC OCEANS 

NOUS42 KNHC ________ (DATE/UTC TIME) 

WEATHER RECONNAISSANCE FLIGHTS 

CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL 

_____ (LOCAL TIME) ___ (TIME ZONE) ___ (DAY) ___ (MONTH/DATE), ____ (YEAR) 

SUBJECT: THE TROPICAL CYCLONE PLAN OF THE DAY (TCPOD) 

VALID ______Z (MONTH) TO ______Z (MONTH) (YEAR) 

TCPOD NUMBER.........(YR)- __________ 

I. ATLANTIC REQUIREMENTS 

1. (STORM NAME, DEPRESSION, SUSPECT AREA) or (NEGATIVE RECON RQMTS) 

FLIGHT ONE (NHC PRIORITY, if applicable) 

 TEAL or NOAA _____ (number) 

A. ___________________________Z FIX/INVEST TIME 

B. ___________________________ MISSION IDENTIFIER 

C. ___________________________Z DEPARTURE TIME 

D. ___________________________ FORECAST POSITION 

E. ___________________________Z TIME ON STATION 

F. ___________________________ ALTITUDE(S) ON STATION 

G. ___________________________ REMARKS (if needed) 

 FLIGHT TWO (if applicable, same as FLIGHT ONE) 

2. (SECOND SYSTEM, if applicable, same as in 1. above) 

3. OUTLOOK FOR SUCCEEDING DAY (NHC PRIORITY, if applicable) 

A. POSSIBLE (Unit) ON STATION REQUIREMENT NEAR (Location) AT 

(Time) Z. 

II. PACIFIC REQUIREMENTS (Same as in ATLANTIC) 

Figure 5-6. Tropical Cyclone Plan of the Day Format 

 
5-12 

5.5.1.3. Anticipated Reconnaissance Requests. Reconnaissance requests can 

be anticipated for a forecast or actual storm location. 

5.5.1.3.1. For the Atlantic, Gulf of Mexico, Caribbean, and Central 

Pacific areas, the requests can be: 

 Up to four 6-hourly fixes per day when a storm is within 500 nm 

of landfall and west of 55oW in the Atlantic, and resources 

permitting, up to 52.5W. 

 Up to eight 3-hourly fixes per day when a storm is forecast to be 

within 300 nm of the U.S. coast, Hawaiian Islands, Puerto Rico, 

Virgin Islands, DOD installations, and other DOD assets when 

specified. 

 Up to two synoptic surveillance missions per 24-hour period for 

potentially land-falling storms. 

5.5.1.3.2. In the Eastern Pacific, reconnaissance missions may be 

tasked when necessary to carry out warning responsibilities. 

5.5.1.3.3. Investigative flights may be requested for disturbances in 

areas defined above, i.e., one or two flights per day dependent upon proximity of landfall and 

upon known or suspected stage of development. 

5.5.1.3.4. Exceptions may be made when additional reconnaissance is 

essential to carry out warning responsibilities. 

5.5.2. DOD and DOC Reconnaissance Aircraft Responsiveness.

5.5.2.1. Requirement Notification. Notification of requirements must proceed 

tasked-on-station time by at least 16 hours plus en route time to the area of concern. 

5.5.2.2. Prepositioning. The "Succeeding Day Outlook" portion of the 

TCPOD provides advance notification of requirements and authorizes units to preposition 

aircraft to forward operating locations. For missions requiring prepositioning, the "Succeeding 

Day Outlook" may not provide adequate advance notification. In this situation, an "Additional 

Day Outlook" may be included in the TCPOD to authorize units to preposition aircraft. 

5.5.2.3. Resources Permitting. When circumstances preclude the appropriate 

notification lead time, the requirement will be levied as "resources permitting." When a 

"resources permitting" requirement is levied in an amendment, the NHC will indicate the priority 

of all existing or remaining requirements. 

5.5.2.4. Emergency Requirement. If a storm develops unexpectedly and 

could cause a serious threat to lives and property within a shorter time than provided for in the 

paragraphs above, CARCAH will contact the reconnaissance units, or higher headquarters, as 

appropriate, and request assistance in implementing emergency procedures not covered in this 

plan. The NHC and CPHC directors have authority to declare an emergency. 
5-13 

5.5.2.5. NOAA WP-3D Availability. At least one WP-3D will be 

operationally configured (per paragraph 5.4.7) and available to respond to requirements within 

24 hours from June 1 through November 30 annually. A second WP-3D with the same 

operational configuration will be available each hurricane season from July 15 to September 30. 

When maintenance and programmatic considerations permit, the second aircraft could be made 

available until November 30 also. The frequency of flights when two aircraft are available and 

with present staffing shall be every 12 hours. 

5.5.3. Reconnaissance Tropical Cyclone Plan of the Day.

5.5.3.1. Preparation. CARCAH will coordinate the TCPOD (Figure 5-6) daily 

during the period from June 1 to November 30 and at other times during the year as required. 

Transmitted TCPODs will be serially numbered each season. 

5.5.3.1.1. CARCAH will coordinate the TCPOD with NHC, the 

53 WRS, and NOAA AOC before publication. 

5.5.3.1.1.1. The coordinated TCPOD is the agency’s RFA to DOD. 

Since DOD’s support to NOAA is congressionally mandated and funded through the DOD 

Appropriations Act, the coordinated TCPOD is considered a validated and approved RFA. 

5.5.3.1.1.2. Combatant command headquarters and their air 

component command headquarters will coordinate on missions by reviewing the proposed 

TCPOD posted at http://www.nhc.noaa.gov/reconlist.shtml, then click ‘For Tomorrow’ under 

‘Plan of the Day.’

5.5.3.1.1.3. Combatant command headquarters and their air 

component command headquarters will pull current DOD missions from 

http://www.nhc.noaa.gov/reconlist.shtml, then click ‘For Today’ under ‘Plan of the Day.’ 

Additionally, the 403rd Current Operations provides a mission setup sheet with reason of 

deviation from TCPOD, as required, to the combatant command and their air component 

operations/command centers. 

5.5.3.1.2. The TCPOD will list all DOC/NOAA AOC and DOD 

required tropical and subtropical cyclone operational reconnaissance missions. Research 

missions will also be listed in the TCPOD when available by transmission time. 

5.5.3.1.3. Amendments to the TCPOD will be published only when 

requirements change. When amended, the impact on each listed flight will be identified (i.e., No 

Change, Change Added, or Cancel). 

5.5.3.2. Dissemination. The TCPOD will be made available to appropriate 

agencies, such as FAA, DOD, and NOAA, which provide support to or control of reconnaissance 

aircraft or are a part of the tropical cyclone warning service. Under normal circumstances, the 

TCPOD will be disseminated by 1830 UTC each day including weekends and holidays. If there 

are no current day or succeeding-day reconnaissance requirements, a negative report, which 
5-14 

covers the appropriate time frame, will be disseminated. Amendments will be disseminated as 

required. 

[NOTE: The TCPOD is disseminated under the header “MIAREPRPD” for AWIPS users 

and “NOUS42 KNHC” for AWDS users. The TCPOD can be accessed via the Internet at 

the National Hurricane Center homepage at www.nhc.noaa.gov, then click on ‘Aircraft 

Reconnaissance’ and then on ‘Plan of the Day.’] 

5.6. Reconnaissance Effectiveness Criteria.

5.6.1. General. Specified reconnaissance times are established to allow sufficient time 

for the forecaster to analyze the data before issuing an advisory. Every effort should be made to 

obtain data at scheduled times. The following criteria will be used to assess reconnaissance 

mission effectiveness: 

5.6.1.1. Tropical Cyclone Fix Mission.

 ON-TIME. The fix is made no earlier than 1 hour before nor later than 1⁄2 

hour after scheduled fix time. 

 EARLY. The fix is made from 1 hour before scheduled fix time to one-half of 

the time interval to the preceding scheduled fix, not to exceed 3 hours. 

 LATE. The fix is made within the interval from 1⁄2 hour after scheduled fix 

time to one-half of the time interval to the succeeding scheduled fix, not to 

exceed 3 hours. 

 MISSED. Data are not obtained within the parameters specified for on-time, 

early, or late. 

[NOTE: Appropriate credit will be given when the aircraft arrives in the requested area 

but is unable to locate a center due to storm dissipation, the absence of a fixable center, or 

rapid movement. Credit will also be given for radar fixes if penetration is not possible due 

to geographic or other flight restrictions.] 

5.6.1.2. Tropical Cyclone Investigative Missions.

 ON-TIME. An observation must be taken within 250 nm of the specified 

coordinates by the scheduled time. 

 LATE. An observation is taken within 250 nm of the specified coordinates 

after the scheduled time but not later than the scheduled time plus 2 hours. 

 MISSED. When the aircraft fails to be within the 250 nm of the specific 

coordinates by the scheduled time plus 2 hours or is unable to provide 

meaningful data. 

 
5-15 

5.6.1.3. Synoptic Surveillance Missions. 

 SATISFIED. Requirements are considered satisfied upon completion of the 

assigned track and the acquired dropwindsonde data are transmitted from the 

aircraft prior to the HPC/OPC deadline for synoptic analysis. 

 MISSED. When the requirements listed above are not satisfied. 

5.6.2. Mission Assessment. The NHC or CPHC will provide CARCAH a written 

assessment of the reconnaissance mission anytime its timeliness or quality is outstanding or 

substandard (see Figure 5-7). Mission requirements levied as "resources permitting" will not be 

assessed for timeliness but may be assessed for quality of data gathered. 

5.6.3. Summaries. CARCAH will maintain monthly and seasonal reconnaissance 

summaries, detailing requirements tasked by NHC and CPHC and missions accomplished. 

5.7. Aerial Reconnaissance Weather Encoding, Reporting, and Coordination. 

5.7.1. Vortex Data. A vortex data message (Figure 5-4) will be prepared for all fixes, 

using all observed vortex fix information, each time the aircraft penetrates the center. 

5.7.2. Aircraft Radar Fix Data. When proximity to land, air traffic control restriction, 

or other factors prevent actual penetration of the vortex by the reconnaissance aircraft, it is 

permissible to fix the cyclone by radar. Radar fixes may be reported in a vortex data message 

using available observed information or as a remark appended to a RECCO observation taken at 

fix time. The remark stating the type of radar fix and quality of the radar presentation is in 

accordance with chapter 8, paragraph 8.3.2. Two examples follow: 

Example 1: RADAR FIX PSBL CENTER 21.5N 83.0W, POOR RADAR 

PRESENTATION, SPIRAL BAND, MET ACCURACY 15NM 

Example 2: RADAR FIX EYE 21 DEG 23 MIN N 78 DEG 42 MIN W GOOD RADAR 

PRESENTATION CIRCULAR EYE DIAM 25 NM OPEN SW. 

5.7.3. Peripheral Data. Storm penetration and collection of peripheral data will 

normally begin at the operational altitude approximately 105 nm from the center as determined 

by the flight meteorologist. 

5.7.4. Mission Coordination. Mission coordination for all missions will be 

accomplished through CARCAH. Meteorological discussions for Central Pacific missions may 

be accomplished directly with the CPHC; however, any changes to tasking will be accomplished 

through CARCAH. 

5.7.5. Post-flight Debriefing. Unless otherwise directed, the flight meteorologist will 

provide either an airborne or post-flight debriefing to the appropriate hurricane center through 

CARCAH to ensure all observations were received and understood. 

5.7.6. Mission Identifier. Regular weather and hurricane reconnaissance messages will 
5-16 

include the five-digit agency/aircraft indicator followed by the CARCAH-assigned 

mission/storm-system indicator. Table 5-3 summarizes elements of the mission identifier. 

5.7.7. Storm Identifier <Storm ID>. To facilitate the automatic ingest into the NHC, 

CPHC, and DOD tropical cyclone forecast computing systems, the storm identifier will be added 

3 spaces after the Vortex Data Message title (see Figure 5-4) in the following format: Vortex 

Data Message BBCCYYYY. For the definition of BBCCYYYY, see Chapter 4, paragraph 

4.3.3. 

5.7.8. Observation Numbering and Content. Air Force aircraft movement 

information (i.e., departure time and location, and ETA’s to locations) will not be included in 

observation remarks. That information should be passed to CARCAH via SATCOM 

administrative messages. The mission identifier will be the first mandatory remark followed by 

the observation number. All observations (RECCO, vortex, dropsonde) from the first to the last 

will be numbered sequentially. HDOBs will be automatically numbered sequentially but 

separately from other observations. When an aircraft is diverted from its original mission to 

fulfill NHC requirements, conclude the original mission by using the last report remark. 

The next observation from the diverted aircraft will use the CARCAH-assigned 

mission identifier, will be numbered OB 01, and will include the time of diversion. 

-EXAMPLERMK AF306 0lBBA INVEST OB 01 DPTD AF306 WXWXA AT 05/1235Z 

 
5-17 

MISSION EVALUATION FORM 

MEMORANDUM FOR: OL-A, 53 WRS/CARCAH 

FROM: (Director, NHC, CPHC) . 

SUBJECT: Mission Evaluation 

 (Mission Identifier) 

PUBLISHED REQUIREMENTS: 

 Premission Coordinates (As Updated Prior to TKO)_____________________N___________________W 

 Flight Pattern __________________________________________________________________________ 

 Mission Requirements Times ______________________________________________________________ 

RECONNAISSANCE MISSION PERFORMANCE: 

 Flight Flown: _____Completely _____Partially _____Other 

 Horizontal Data Coverage: _____Complete _____Timely _____Accurate 

 _____Incomplete _____Untimely _____Inaccurate 

 Vertical Data Coverage: _____Complete _____Timely _____Accurate 

 _____Incomplete _____Untimely _____Inaccurate 

 Requirements Accomplished: _____On Time _____Early _____Late 

 _____Missed 

OVERALL MISSION EVALUATION: 

 OUTSTANDING____________ 

 UNSATISFACTORY____________ FOR: 

 COMPLETENESS____________ TIMELINESS____________ ACCURACY____________ 

 EQUIPMENT_______________ PROCEDURES____________ OTHER_______________ 

REMARKS: (Brief but specific) 

________________________ 

FORECASTER's SIGNATURE 

Figure 5-7. Mission Evaluation Form

 
5-18 

Table 5-3. Elements of the Mission Identifier 

AGENCY/ 

AIRCRAFT Mission Storm System Indicator 

Agency + Aircraft 

Number12

Sequential number 

of mission in this 

storm 

Two-digit depression 

number or two letter 

identifier if not a 

depression or greater3

Location 

A, E, C, or W4

Storm name or mission 

type (i.e., CYCLONE 

or INVEST 

-EXAMPLESAF306 0201C CYCLONE 

USAF aircraft 5306 on the second mission for Tropical or Subtropical 

Depression One in the Central Pacific. Mission type can be fix or 

surveillance, as specified in the TCPOD.

AF307 0403E CARLOS 

USAF aircraft 5307 on the fourth mission for the third classified 

tropical or subtropical system that formed in the Eastern Pacific and 

acquired the name Carlos. 

NOAA2 01BBA INVEST NOAA aircraft 42RF on the first mission to investigate the second 

unclassified suspect area in the Atlantic, Gulf of Mexico, or Caribbean. 

NOAA9 WAWXA AL92 NOAA aircraft N49RF on the first flight of a sequence of non-tasked 

research missions into Atlantic suspect area AL92. 

NOAA3 WF13A KARL 

NOAA aircraft N43RF on the sixth flight of a sequence of non-tasked 

research missions into the system that developed from suspect area 

AL92 into the thirteenth tropical or subtropical cyclone in the Atlantic 

Basin and acquired the name Karl. 

5.7.9 Corrections to Observations. A correction indicator should be appended to the 

WMO abbreviated header after the date/time group and to any lines containing the mission 

identifier and observation number within corrected aircraft messages. This includes the first 

remark line in a RECCO, Item P in a vortex data, each of the 61616 lines in a sonde TEMP 

DROP code, and the second line in an HDOB data message. The first corrected message will 

have an indicator of CCA; subsequent corrections will have indicators of CCB, CCC, etc. 

Examples of corrected observations are in Table 5-4 below: 

 

 

1

 AF plus last 3 digits of tail number 

2

 NOAA, plus last digit of aircraft registration number 

3

 The letters CC should not be used in an invest identifier 

4

 A=Atlantic, Caribbean, or Gulf of Mexico; E=Eastern Pacific; C=Central Pacific; W=Western Pacific 
5-19 

Table 5-4. Examples of Corrected Observations

EXAMPLES 

URNT11 KNHC 111629 CCA 

97779 16264 51286 90000 30400 09054 11071 /3136 

40545 

RMK AF303 2709A IKE OB 01 CCA

Correction for RECCO message OB 

01 from the AF303 02709A IKE 

mission.

URNT12 KNHC 130552 CCB 

VORTEX DATA MESSAGE AL092008 

A. 13/04:47:20Z 

B. 28 deg 52 min N 

 094 deg 37 min W 

 . 

 . 

 . 

P. AF301 3509A IKE OB 02 CCB 

MAX FL WIND 103 KT NE QUAD 04:30:40 Z 

CORRECTED FOR TIME IN ITEM A

Second correction for vortex data 

message OB 02 from the AF301 

3509A IKE mission.

UZNT13 KWBC 080739 CCA 

XXAA 58062 99300 70760 11606 99/// ///// ///// 00956 25616 09512 

 . 

 . 

 . 

61616 NOAA9 1109A IKE OB 03 CCA 

62626 0629 LST WND 894 AEV 20704 CORRECTED RPT DLM WND 

08509 0071 

82 = 

XXBB 58068 99300 70760 11606 00/// ///// 11007 26217 22977 24010 

 . 

 . 

 . 

61616 NOAA9 1109A IKE OB 03 CCA 

62626 0629 LST WND 894 AEV 20704 CORRECTED RPT DLM WND 

08509 0071 

82 =

Correction for sonde TEMP DROP 

code message OB 03 from the NOAA9 

1109A IKE mission.

5.8. Operational Flight Patterns. This section details the operational flight patterns that 

provide vortex and peripheral data on tropical and subtropical cyclones. 

5.8.1. Flight Pattern ALPHA Operational Details.

5.8.1.1. Flight Levels and Sequence. Flight levels will normally be 1,500 ft, 

925 hPa, 850 hPa, or 700 hPa, depending on data requirements and flight safety. Legs will 

normally be 105 nm long and flown on intercardinal tracks (45 degrees off cardinal tracks). The 

flight sequence is shown in Figure 5-8. The pattern can be started at any intercardinal point and 

then repeated throughout the mission. Prior to starting an inbound or outbound track the aircrew 

should evaluate all available data, e.g., radar presentation, satellite photo, for flight safety. Once 

started on course, every effort should be made to maintain a straight track and the tasked altitude. 

A horizontal observation is required at each leg end point. This data is transmitted immediately. 
5-20 

The ALPHA pattern may be modified to satisfy unique customer requirements (such as 

extending legs to examine the wind profile of a strong storm) or because of proximity of land or 

warning areas. 

Figure 5-8. Flight Pattern ALPHA 

5.8.1.2. Vortex fix data. On each transit of the center a fix will be made and a 

vortex data message completed, using data gathered on the inbound track since the previous fix 

and will be transmitted immediately. Center dropsonde data will also be provided for scheduled 

fixes made at 850 hPa or above. The dropsonde will be released at the flight-level center 

coordinates (item BRAVO of the vortex data message). For fixes when dropsonde-measured 

SLP is not available, an extrapolated SLP will be computed and reported. 

5.8.2. Investigative Missions. An investigative mission is tasked on tropical or 

subtropical disturbances to determine the existence or non-existence of a closed circulation, 

supply reconnaissance observations in required areas, and locate the vortex center, if any. 

5.8.2.1. Flight Levels. Flight level will normally be at or below 1,500 ft 

absolute altitude but may be adjusted as dictated by data requirements, meteorological 

conditions, or flying safety factors. 

5.8.2.2. Vortex Fix. A vortex data message is required if a vortex fix is made. 

5.8.2.3. Closed Circulation. A closed circulation is supported by at least one 

sustained wind reported in each quadrant of the cyclone. Surface winds are preferred. 

5.8.2.4. Flight Pattern. The preferred approach is to fly to the tasked 

coordinates of the forecasted center and then execute a pattern as observed conditions dictate. 

Suggested patterns are the X, Box, or Delta patterns, but the flight meteorologist may choose any 

approach. See Figure 5-9. Turns are usually made to take advantage of tailwinds whenever 

possible. Note: The depicted pattern may be converted to a mirror image if entry is made from a 

different direction. 

 On the X pattern, the aircraft is turned to head directly towards the center, as 
5-21 

indicated by the surface or flight level winds. The aircraft is flown through 

the calm center until winds from the opposite direction occur (second 

quadrant). The aircraft is then turned to a cardinal heading until a wind shift 

occurs (third quadrant). Finally, the aircraft is turned towards the center and 

flown straight through the center to the last quadrant. 

 On the Box pattern, the aircraft is flown on cardinal headings around the 

suspected center. The track resembles three sides of a square. 

 On the Delta pattern, the aircraft is flown on a cardinal heading to pass 60 nm 

from the forecasted center. After observing a wind shift (second quadrant) the 

aircraft is turned to pass through the center until winds from the opposite 

direction occur (third quadrant). Finally, the aircraft is turned on a cardinal 

heading (parallel to the initial heading) to pick up the fourth quadrant winds. 

If data indicate that the aircraft is far north of any existing circulation, the 

pattern is extended as shown by the dashed lines. 

Figure 5-9. Suggested Patterns for Investigative Missions

5.8.3. Synoptic Surveillance Missions. A synoptic surveillance mission is tasked to 

measure the large-scale wind and thermodynamic fields within approximately 800 nautical miles 

of tropical cyclones. Specific flight tracks will vary depending on storm location and synoptic 

situation, and multiple aircraft may be required to satisfy surveillance mission requirements. 

5.8.4. Eyewall and Outer-Wind Field Sampling Modules. These are patterns of 

dropwindsonde releases designed to measure the maximum surface wind, as well as the extent of 

hurricane and tropical storm force surface winds. They are meant to be flown using the 

operational alpha pattern. Dropwindsonde releases in these modules are in addition to any other 

releases required by Table 5-1. 

 
5-22 

5.8.4.1. Eyewall Module. While executing a standard alpha pattern to satisfy 

a fix requirement, one sounding will be taken during each inbound and outbound passage 

through the eyewall (except as noted below), for a total of four soundings. The releases should 

be made at or just inward (within 1-2 km) of the flight-level radius of maximum wind (RMW). 

If the radar presentation is suitable, the inner edge of the radar eyewall may be used to identify 

the release point. If possible, and when resources and safety permit, two dropwindsondes, 

spaced less than 30 seconds apart, should be deployed on the inbound leg on the side of the 

storm believed to have the highest surface winds (normally the right-hand side). In this case, the 

outer of the two releases should be made at the RMW, with the second release following as soon 

as possible. Typically, the eyewall module will be tasked within 48 hours of a forecasted 

hurricane landfall. 

5.8.4.2. Outer-Wind Field Module. On an alpha pattern, deploy 

dropwindsondes at 50 nm intervals from the center on each of two successive inbound and 

outbound legs, outward to 200 nm. A release should also be made at the midpoint of the cross 

(downwind) leg, for a total of 19 soundings, including center drops. The length of the legs and 

the sounding interval may be adjusted, depending on the size of the storm. 

5.9. Aircraft Reconnaissance Communications.

5.9.1. General. The 53 WRS WC-130 and NOAA WP-3D aircraft will normally 

transmit reconnaissance observations via the Air Force Satellite Communications System 

(AFSATCOM) or commercial SATCOM. Figures 5-10 and 5-11 depict the ASDL and 

AFSATCOM communications links. The NOAA G-IV will normally transmit WMO Temp 

Drop messages via commercial SATCOM. Flight meteorologists should contact CARCAH 

following the first fix, and periodically throughout the mission. 

5.9.2. Backup Air-to-Ground Communications. The weather reconnaissance crew 

may relay weather data via SATPHONE or HF phone patch to the weather data monitor. 

Monitors will evaluate these reports and disseminate them through the Air Force's Automated 

Weather Network (AWN) or to the weather communications facility at Suitland, Maryland. 

Specific radio procedures and terminology will comply with Allied Communications Publication 

125, Standard Telephone and Radio Procedures. 

5.9.3. Aircraft-to-Satellite Data Link (ASDL)-Equipped Aircraft. Aircraft equipped 

with ASDL have the option to utilize the ASDL system. Prior to the beginning of the hurricane 

season, each ASDL-equipped aircraft will perform a ground or airborne test of the equipment 

and data ground handling procedures to determine the equipment reliability, transmission errors, 

and time lapse between transmission of the data from the aircraft and receipt of the data by the 

hurricane forecaster. Test data will be forwarded to the Chair, Working Group for Hurricane and 

Winter Storms Operations and Research. 

 
5-23 

 Figure 5-10. Schematic of Aircraft-To-Satellite Data Link for NOAA P-3 Aircraft

 
5-24 

 Figure 5-11. Schematic of Aircraft-To-Satellite Data Link for AFRC WC-130 Aircraft

[Note: An Internet link from Keesler AFB to NHC provides the capability for all observation types 

to be passed directly to NHC without going through Offutt Air Force Base.] 

 

Internet link (see 

“Note” below)
5-25 

5.9.4. Backup CARCAH Procedures. Satellite ground stations, which are used to 

receive and process data from AFRC reconnaissance aircraft, are installed at CARCAH (located 

within NHC) and the 53 WRS (located at Keesler Air Force Base). The 53 WRS ground station 

has a similar configuration and communications capability as the satellite ground station installed 

a CARCAH, except that the CARCAH ground station has additional capability to stream data 

using serial RS-232 communications to NHC local servers. The ground station at the 53 WRS 

can fully transmit data using SATCOM and land line to the CARCAH ground station. Both 

ground stations can send data to AFWA’s Weather Product Management and Distribution 

System (WPMDS)—WPMDS then relays all AFRC/53 WRS reconnaissance data to the NWS 

Gateway for world-wide distribution. In the event that backup procedures are required due to 

severe communications failures, severe weather conditions, or other extreme events affecting 

NHC, some or all CARCAH responsibilities will be transferred to the 53 WRS, ensuring 

reconnaissance service is uninterrupted. 

5.9.4.1. Satellite Antenna Communications Failure at NHC. If an outage is 

expected to be temporary, CARCAH will coordinate with the 53 WRS to have operators man the 

ground station located at the backup site. They will be responsible for maintaining contact with 

airborne reconnaissance aircraft and relaying data via land line to the CARCAH ground station. 

In the event communications lines between the backup site and NHC are also severed, the 53 

WRS ground station will be configured to transmit data directly to the WPMDS. No procedure is 

currently implemented for sending the aircraft data directly to local servers at HPC or CPHC 

(NHC’s COOP backup site); consequently, all data or observations will need to be accessed from 

the WPMDS or obtained from the NWS Gateway. 

For long-term outages, CARCAH will send personnel to the backup site. They 

will monitor the aircraft data and ensure they are transmitted to the WPMDS, NWS servers, and 

external users from that location. 

5.9.4.2. Internet Communications Failure. In the event there is a long-term 

network communications outage between NHC and AFWA, the CARCAH ground station will 

still be able to receive aircraft data and send them to local NHC servers. If Internet access 

problems originate at NHC, the CARCAH ground station will be configured to relay the data to 

the backup site ground station via SATCOM. The 53 WRS ground station will in turn be 

configured to automatically transmit them to the AFWA WPMDS server. However, if the 

Internet disruptions occur at AFWA, no data can be sent to the AWN, NWS servers, and external 

users until service is restored. 

5.9.4.3. NHC Emergency Backup Plan. In the event NHC activates the HPC or 

CPHC COOP backup plan, designated CARCAH personnel will deploy to the backup site to 

operate the 53 WRS ground station. The reconnaissance data will be obtained at the HPC COOP 

site either through the WPMDS or the NWS Gateway. 

6-1 

CHAPTER 6 

AIRSPACE OPERATIONS 

6.1. Pre-mission Coordination. 

6.1.1. Federal Aviation Administration (FAA) Coordination. 

6.1.1.1. Responsibilities. The Air Traffic Control System Command Center 

(ATCSCC) and Air Route Traffic Control Centers (ARTCC) are responsible for coordination in 

support of the NHOP. 

6.1.1.2. ATCSCC Procedures. 

 Review the TCPOD available at http://www.nhc.noaa.gov/reconlist.shtml, by 

1830 UTC. Normal notification of scheduled NHOP flights is accomplished 

through the TCPOD (1 June through 30 November). 

 Activate the Hurricane Desk, when required. 

 Review the Mission Coordination Sheet (see Appendix L). Prepare a public 

Flow Evaluation Area (FEA) based on the latitude/longitude points specified 

in the Mission Coordination sheet when a mission is scheduled to be flown. 

The FEA naming convention is the aircraft call sign. Modify the FEA when 

requested by the affected facilities. (The flying unit will fax their Mission 

Coordination Sheet to the ATCSCC and affected ARTCCs 1-2 hours prior to 

flight departure time). 

 Coordinate with the impacted ARTCCs as required and designate a Primary 

ARTCC when the Operations Area includes multiple ARTCCs. 

 In the event of an unscheduled mission that is not listed on the TCPOD, the 

flying unit will contact the ATCSCC. The ATCSCC will initiate a conference 

call with the unit and all affected ARTCCs. 

 When requested, assist ARTCCs with traffic flow priorities if the hurricane 

reconnaissance flight will impact air traffic. The hurricane reconnaissance 

flight receives priority as specified in JO Order 7110.65. 

 Coordinate with Air Traffic Services Cell (ATSC), as needed, when informed 

by an ARTCC of a disapproval of hurricane reconnaissance flight to enter a 

Special Use Airspace (SUA) or Special Activity Airspace (SAA). 

 Conduct hurricane and customer teleconferences, as necessary. 

6.1.1.3. ARTCC Procedures. 

 Review the TCPOD at http://www.nhc.noaa.gov/reconlist.shtml, by 1830 

UTC. Normal notification of scheduled NHOP flights is accomplished 

through the TCPOD (1 June through 30 November). 

 Review the Mission Coordination Sheet (see Appendix L) - the flying unit 

will fax their Mission Coordination Sheet to the ATCSCC and affected 

ARTCCs 1-2 hours prior to flight departure time. 

 Coordinate with all impacted Center and Terminal facilities within their area 

of responsibility. 
6-2 

 Coordinate with all impacted military facilities (e.g., FACSFAC) through the 

applicable Military Operation Desks within their area of operations and 

responsibility to ensure all offshore airspace (i.e., Warning Areas, SUA, SAA) 

that is activated by the military is protected for NHOP flights, when required. 

If SUA or SAA release is not approved, contact the ATCSCC. 

 When requested, assign 53 WRS and NOAA aircraft the dedicated NORAD 

transponder code associated with their call sign, which is listed on the Mission 

Coordination Sheet. 

 When designated by ATCSCC as the Primary ARTCC, responsibilities will 

include: 

 Coordinate with CARCAH and aircrew(s) on flight plan specifics, when 

necessary. 

 If the mission profile changes, coordinate with the ATCSCC for FEA 

modifications, and ensure affected ARTCCs are aware of the change. 

 Advise the ATCSCC and affected ARTCCs of any mission cancellation or 

delay information received from the flying unit. 

6.1.2. Pre-Mission Coordination. 

6.1.2.1. Flying Agencies (other than the 53 WRS or NOAA AOC) Premission Coordination.

 NASA, NRL, NSF or any other agency planning research missions, including 

Unmanned Aircraft Systems (UAS), into or around the forecast or actual 

storm location will coordinate with affected ARTCCs and CARCAH as soon 

as possible prior to all flights. 

 The flying unit will fax their Mission Coordination Sheet to the ATCSCC and 

affected ARTCCs 1-2 hours prior to flight departure time. 

 Flights in support of the NHOP (conducted by the 53 WRS and NOAA AOC 

operations) are normally published in the TCPOD at 

http://www.nhc.noaa.gov/reconlist.shtml by 1830 UTC. Reference the 

TCPOD to assist in de-confliction efforts. Required operational 

reconnaissance missions flown by the 53 WRS and NOAA AOC will be 

outlined in the TCPOD. Flights other than 53 WRS and NOAA AOC tasked 

operational missions should be listed in the TCPOD remarks section. 

 CARCAH coordination is normally restricted to what is required between the 

53 WRS, NOAA AOC, NHC, and ARTCCs in support of operational tasking. 

Due to staffing constraints, the CARCAH unit’s operating hours vary and 

often depend on the requirements levied. Its ability to coordinate nonoperational missions is extremely limited. Research missions can only be 

considered on a non-interference basis when flown concurrently with a tasked 

mission or when data collected will be directly beneficial to NHC in real time. 

However, CARCAH will need to have advance notification of all planned 

research missions in areas where operations are being conducted, including 

proposed flight tracks, aircraft altitudes, and locations where expendables may 

be deployed; this information can be e-mailed to ncep.nhc.carcah@noaa.gov

or faxed to 305-553-1901 (please indicate “CARCAH” on faxed materials). 

 IAW JO 7110.65, only 53 WRS and NOAA aircraft performing tasked 
6-3 

operational missions will have priority for access to the operations area. 

 Dedicated NORAD Mode 3/A Transponder Codes. N/A. 

6.1.2.2. CARCAH Pre-mission Coordination. CARCAH’s pre-mission 

coordination procedures include: 

 Publishing the TCPOD when required. 

 Coordinating with the affected ARTCCs and ATCSCC as required. 

 For unscheduled missions, notifying the flying units and ATCSCC. 

 Notifying 53 WRS and NOAA AOC flight crews when other research 

missions will be airborne in the operations area at the same time. 

6.1.2.3. 53 WRS and NOAA AOC Pre-mission Coordination.

 Mission Coordination Sheet. As soon as possible, but no later than 1-2 hours 

prior to departure time, fax the Mission Coordination Sheet (see Appendix L) 

to the ATCSCC and affected ARTCCs (see Appendix I). 

 Missions Not Listed in the TCPOD. In the event of an unscheduled mission, 

the flying unit will contact the ATCSCC. The ATCSCC will initiate a 

conference call with the unit and all affected ARTCCs. 

 Dedicated NORAD Mode 3/A Transponder Codes. 53 WRS and NOAA 

NHOP missions have dedicated NORAD mode 3/A transponder codes. These 

codes are only applicable in FAA controlled airspace in the Gulf of Mexico 

and Atlantic. They are issued by the 601st Air & Space Operations Center, 

Airspace Management Team (DSN 523-5837 or COM 850-283-5837) and 

must be renewed on an annual basis. For season 2012 the codes are as 

follows: 

 TEAL 70–79: 7552-57 & 7560-63 (expire 31 Dec 2012) 

 NOAA 42, 43, and 49: 5050-5054 

6.1.2.4. Mission Coordination Sheet. All missions must provide a Mission 

Coordination Sheet to the affected ARTCCs and the ATCSCC 1-2 hours prior to departure time 

(see Appendix L). 

6.1.2.5. Aircraft Call Signs.

 53 WRS: “TEAL 70 through 79” (WC-130J aircraft) 

 NOAA AOC: “NOAA 42 and 43” (WP-3D aircraft); “NOAA 49” (G-IV 

aircraft) 

 NASA: “NASA817” (DC-8 aircraft); “NASA 871 & 872” (Global Hawk 

UAS) 

 NRL: “WARLOCK 587” (NP-3 aircraft) 

 NSF/NCAR: “N677F” (G-V aircraft) 

6.1.2.6. Flight Plan Filing Procedures. Flight plans must be filed with the 

FAA as soon as practicable before departure time. For flights into all U.S. FIRs, include delay 

time in the Route portion of the International Flight Plan - this will keep the IFR flight plan 

active throughout operations in the delay area while in FAA controlled airspace. Due to limited 

information that is displayed on FAA controller screens, it is recommended that only the 

following remarks be included in the “Other Information” block: 
6-4 

 “EET” to FIR boundaries,

 Navigation Performance (ex. RNP-10); and 

 “RMK/MDCN” diplomatic clearance information. 

6.1.2.7. Mission Cancellation. When a mission is cancelled or delayed, the 

unit flying the mission must notify the Primary ARTCC as soon as possible. 

6.1.3. Annual Liaison Meetings.

6.1.3.1. At a minimum, an annual liaison meeting will be conducted between 

the following participants: 53 WRS, NOAA AOC, the ATCSCC and affected ARTCCs. This 

meeting will review the previous season’s operations, any proposed changes to the current 

NHOP, FAA liaison flights, and ICAO operations. This meeting will take place annually, 

normally in conjunction with the OFCM-sponsored Interdepartmental Hurricane Conference 

(IHC). 

6.1.3.2. Annual ARTCC and ATCSCC visits and briefings by 53 WRS and 

NOAA AOC aircrews and FAA Military Liaisons are encouraged. These joint visits emphasize 

the unique challenges and non-standard operational procedures, communication and coordination 

required to successfully and safely accomplish the Hurricane Hunter mission. 

6.1.4. FAA Familiarization Flights. FAA Familiarization Flights on USAF (IAW AFI 

11-401 and DOD 4515.13-R) and NOAA Hurricane Hunter aircraft are authorized and 

encouraged. These flights are important to ensure FAA controllers have a better understanding of 

Hurricane Hunter operations and how these missions play a vital role to inform emergency 

planners and coastal citizens on the storm’s track and intensity as they approach the U.S. 

coastline. 

6.2. Mission Execution. 

Note: No procedure in the NHOP precludes Aircraft Commanders from exercising their 

authority in the interest of safety or during an aircraft emergency. 

6.2.1. NHOP Missions (At or Below FL150). NOAA and 53 WRS NHOP (and 

NWSOP) missions have dedicated NORAD mode 3/A transponder codes associated with call 

signs TEAL 70–79 (7552-57 & 7560-63) (expire 31 Dec 2012) and NOAA 42, 43, and 49 (5050-

5054), respectively. Both NOAA and 53 WRS aircrews will request to be assigned their 

dedicated mode 3/A code on the ground or after airborne. 

6.2.1.1. Priority Handling. When requested by the aircrew, ATC will provide 

TEAL and NOAA aircraft priority handling. The aircraft commander will only ask for priority 

handling when necessary to accomplish the mission. 

6.2.1.2. International Airspace. International Airspace is defined as the 

Airspace beyond a Sovereign State’s 12nm territorial seas limit. Beyond this limit ICAO rules 

apply. In International Airspace, VFR flight is not allowed at night. In Class A Controlled 

Airspace, aircraft must operate using IFR procedures; ATC separation is provided between IFR 

aircraft. In Class E Controlled Airspace, both VFR and IFR operations are allowed; separation is 
6-5 

provided between IFR aircraft but not with VFR traffic; traffic information is provided to VFR 

traffic and about VFR traffic, as far as practical. In Class F and G Uncontrolled Airspace, both 

VFR and IFR operations are allowed. When operating in uncontrolled airspace, flight 

information service, which includes known traffic information, is provided and the pilot is 

responsible for arranging the flight to avoid other traffic (ICAO, Annex 11). 

6.2.1.3. IFR Procedures and Clearance. Aircrews will conduct flight 

operations to the maximum extent possible utilizing IFR procedures and will not normally 

conduct flight operations under the provisions of "Due Regard." While entering, within, or 

exiting the Operational Delay Area, if the aircraft commander determines that mission, weather, 

and/or safety requirements dictate, then they may exercise their operational prerogative and 

declare “Due Regard.” When conducting “Due Regard” operations, aircrews will comply with as 

many IFR procedures as possible. Before declaring “Due Regard,” the aircrew will notify ATC 

of their intentions – ATC will retain flight plan information. If an aircrew is unable to notify 

ATC beforehand, they will inform them when able. As soon as practical, the aircrew will notify 

ATC that they are terminating “Due Regard” operations and request resumption of IFR services. 

These procedures do not preclude aircraft commanders from exercising their authority in the 

interest of safety or during an aircraft emergency. 

6.2.1.4. Altitude Assignment and Aircraft Separation. Authorized aircraft 

may request to operate at a single altitude or within a block. Multiple aircraft may operate in the 

same vicinity but at different altitudes at the same time. In order to promote mission 

effectiveness, aircrews from NOAA AOC and the 53 WRS will file and request the minimum 

block altitudes to meet their mission requirements (i.e., do not request the block at or below 

FL150 if the mission can be accomplished in the block FL090-110). 

 Operations in Controlled Airspace. While IFR, ATC will assign an altitude 

or a block of altitudes and provide standard vertical separation between all 

IFR aircraft and will provide VFR traffic advisories as far as practical. Prior to 

departing controlled airspace, advise ATC and state your intentions; ATC will 

not cancel your IFR flight plan. 

 Operations in Uncontrolled Airspace (Class F and G). Per JO 7110.65, 

ATC is not authorized to assign altitudes in nor provide separation between 

aircraft in uncontrolled airspace. While in uncontrolled airspace, the Aircraft 

Commander is the IFR clearance authority. In addition, aircrews are 

responsible for maintaining their own separation from the surface of the sea, 

obstacles, and oil platforms while operating below the Minimum IFR Altitude 

(MIA). In Class F and G Uncontrolled Airspace, both VFR and IFR 

operations are allowed. When operating in uncontrolled airspace, flight 

information service, which includes known traffic information, is provided 

and the pilot is responsible for arranging the flight to avoid other traffic 

(ICAO, Annex 11). 

[Note: When an aircraft declares “Due Regard,” ATC will not be responsible for that 

aircraft’s separation from other aircraft, but the Operational Delay Area will remain 

active.]

6.2.1.5. Operational Delay Area. The Operational Delay Area is ATC 

Assigned Airspace (ATCAA) and is a cylinder of airspace typically defined by a block altitude 

at or below FL150, with a radius of 150 nm around a set of center coordinates. The operations 
6-6 

area may include several different classifications of airspace and environments: controlled, 

uncontrolled, radar contact, non-radar contact, oceanic, international airspace, domestic airspace, 

and/or terminal areas and may encompass several controlling agencies. This area excludes the 

terminal areas (Class D Airspace) depicted on the NHOP Operational Maps (see Appendix K), 

and any other airspace within 50 NM of the CONUS shoreline until radio contact is established 

with ATC. If not in radar contact within the area as shown on the NHOP Operational Maps (see 

Appendix K), the aircrew will make position reports in relation to designated navigational aids as 

requested by ATC along the coast. Any changes to the operating area will be coordinated with 

the primary ARTCC. 

6.2.1.6. ATC Communications. The aircrew normally maintains ATC 

communications with only the primary ARTCC. When operating within an ATC Terminal Area 

depicted on the NHOP Operational Maps (see Appendix K), the aircrews will be in contact with 

both the primary ARTCC and the Terminal Facility if it is operating. Normally, VHF, UHF or 

HF radios will be used for communications with ATC, when within range. In the storm 

environment, HF exhibits poor propagation tendencies. When HF is unusable, satellite 

communications (SATCOM) may be used as a back-up (see Appendix I). IFR aircraft flying in 

domestic or international airspace are required to maintain continuous two-way communications 

with the ATC/FIR even while flying in Uncontrolled Airspace (Class F or G). Monitor the 

active ATC radio frequency for any traffic transiting the Area. 

[Note: While in international airspace, aircrews will make periodic “Operations Normal” 

calls to the primary ARTCC if not in radar contact and no transmissions have been made 

within the previous 20–40 minutes (reference: ICAO 4444/RAC 501/12 VI, 2.1).] 

6.2.1.7. Backup ARTCC Communications Procedures. CARCAH 

maintains contact with participating aircraft at all times and is allowed to relay ATC clearances 

through any means available. CARCAH is responsible for ensuring that ATC clearances, 

clearance requests and messages are relayed in an accurate manner. Only use this method when 

the aircraft or ATC is unable to contact each other. 

6.2.1.8. Participating Aircraft/Aircrew Procedures. A “Participating 

Aircraft/Aircrew” is defined as an Aircraft, Remote Piloted Aircraft (RPA) or Unmanned Aerial 

System (UAS) listed in the TCPOD or conducting a tasked operational mission. CARCAH will 

advise aircrews when other participating aircraft, RPA or UAS will be in the operations area and 

brief call signs and mission information. 

The following actions will be taken by the aircrews to de-conflict operations and 

enhance situational awareness with other participating aircraft while in the Operational Delay 

Area: 

 Set 29.92 (inches Hg) in at least one pressure altimeter per aircraft. 

 Contact (Primary: VHF 123.05 MHZ, Secondary: UHF 304.8 MHZ, Back-up: 

HF 4701 KHz) the other participating aircraft and confirm (as a minimum) the 

pressure altitude, location relative to a center point position, true heading, and 

operating Altitude or Block Altitude. Continue to monitor the frequency 

during the duration of the flight. 

 Even if aircraft are cleared by ATC to operate in blocks altitudes that are 

1,000 feet apart (i.e., TEAL 70 is Block 090-110 and NOAA 42 is Block 060-
6-7 

080), aircrews will not fly within 2,000 feet (vertical) if closer than 10NM 

(using Air-to-Air TACAN and/or TCAS) of other participating aircraft 

operating in the same area of interest without concurrence of the other 

participating aircraft. Note: If unable to maintain assigned altitude or block, 

immediately notify all participating aircraft and take actions to ensure 

sufficient vertical and/or lateral separation is maintained or attained as soon as 

practical. 

 While in the Operational Delay Area use: “see and avoid” operations, 

operating in a different operational area sector (NW, NE, SW, SE), airplaneto-airplane communication position reports, Air-to-Air TACAN, TCAS, 

RADAR, GPS and situational displays/maps to maintain awareness of the 

other aircraft’s location. 

6.2.1.9. Weather Dropwindsonde Instrument Release. The aircraft 

commander is the sole responsible party for all dropwindsonde releases or sensor activations. 

Aircraft commanders will ensure coordination with other participating aircraft prior to release or 

activation. (Examples of weather instruments are dropwindsondes and oceanographic profilers 

(OP)). 

6.2.2. Buoy Deployment Mission. Regardless of the Designated Class of Airspace (A 

through G) the following rules apply: 

6.2.2.1. Flight Plan. A normal IFR flight plan will be filed for this mission. 

The coordinates for some of the planned deployments may need to be changed while en route to 

adjust to the forecast track of the storm. The aircraft routing will not be altered by ATC because 

the buoys must exit the aircraft in a specified order and they cannot be rearranged in flight. 

6.2.2.2. IFR Procedures and Clearance. It is preferred that these missions be 

filed and flown using IFR procedures in either controlled or uncontrolled airspace. However, 

with the concurrence of the aircraft commander, they may be flown VFR. If this change is made 

en route, ATC flight following and traffic advisories will be requested by the aircrew, and any 

changes to the route of flight must be relayed to ATC by the aircrew. 

6.2.2.3. Altitude. Aircrews are responsible for maintaining their own 

clearance from the surface of the sea, obstacles, and oil platforms while operating below the 

Minimum IFR Altitude (MIA). 

6.2.2.4. Communications. See paragraphs 6.2.1.6 – 6.2.1.7. 

6.2.2.5. Participating Military Aircraft (does not apply to NOAA aircraft). 

If there are two or more TEAL aircraft deploying buoys in the same area at the same time, they 

can accept MARSA operations with each other and must relay that to ATC. This will not cancel 

their IFR clearance but will allow ATC to no longer be responsible for providing aircraft 

separation between TEAL aircraft. The TEAL aircraft must be in communication with each 

other and have operating TCAS on at least one of the aircraft. At least one of these aircraft will 

have SATCOM data relay capability on board. 

6.2.2.6. Priority Handling. ATC will provide aircraft priority handling to and 
6-8 

from the deployment area only when specifically requested by the aircrew. The aircraft 

commander will only ask for priority handling when necessary to accomplish the mission. 

6.2.3. High Altitude Synoptic Track Missions. 

6.2.3.1. Flight Plan. A normal IFR flight plan will be filed for this mission. 

An Altitude Reservation (ALTRV) request is not required.

6.2.3.2. NOTAM. A NOTAM will be submitted by the 53 WRS, NOAA 

AOC, NASA, NSF, or NRL for any High Altitude Synoptic Track mission that will release 

weather instruments. The NOTAM must contain individual coordinates or an area defined by 

coordinates for all releases. Submit NOTAM request per Appendix D procedures. 

6.2.3.3. Priority Handling. ATC must provide priority handling, for TEAL 

and NOAA mission aircraft during Synoptic Track Missions only when specifically requested by 

the aircrew.

6.2.3.4. Release of Dropsondes. During NHOP missions and when 

operationally feasible, dropsonde instrument releases from FL 190 or higher and sensor 

activation must be coordinated with the appropriate ARTCC/CERAP (Combined 

Center/RAPCON) by advising of a pending drop or sensor activation about 10 minutes prior to 

the event when in direct radio contact with ATC. When ATC has radar contact with the aircraft, 

they will notify the aircrew of any known traffic below them that might be affected. The aircraft 

commander is solely responsible for release of the instrument after clearing the area by all means 

available.

 When contact with ATC is via ARINC, event coordination must be included 

with the position report prior to the point where the action will take place, 

unless all instrument release points have been previously relayed to the 

affected ATC center(s). Contact between participating aircraft must be made 

using the frequencies listed in paragraph 6.2.1.8., second bullet.

 During NHOP missions, approximately five (5) minutes prior to release the 

aircrew will broadcast in the blind on radio frequencies 121.5 MHZ and 243.0 

MHZ to advise any traffic in the area of the impending drop. Pilots must not 

make these broadcasts if they will interfere with routine ATC communications 

within the vicinity of an ATC facility. The aircraft commander is responsible 

for determining the content and duration of a broadcast, concerning the release 

or sensor activation.
7-1 

CHAPTER 7 

SATELLITE SURVEILLANCE OF TROPICAL AND SUBTROPICAL CYCLONES 

**Incorporated Change 2 on October 12, 2012 for Chapter 7, pages 7-1 to 7-3, and 7-7**

7.1. Satellites. 

7.1.1. Geostationary Operational Environmental Satellite (GOES). Using modern 

3-axis stabilization for orbit control, GOES-13 14 (GOES-East) at 75W and GOES-11 15 

(GOES-West) at 135W support the operational two-GOES constellation. Independent imager 

and sounder instruments eliminate the need to time share, yielding an increase in spatial 

coverage of image and sounder data at more frequent scanning intervals. The GOES also 

provides higher resolution and additional spectral channels than its predecessor, affording the 

hydrometeorological community improvements in detection, monitoring, and analysis of 

developing tropical cyclones. From 135W and 75W, routine GOES satellite data coverage is 

extensive, stretching from the central Pacific through the Americas to the eastern Atlantic, 

including the vital breeding grounds for tropical cyclones. 

 Routinely, each GOES schedule provides two views of the CONUS (GOES-11 West 

view is termed PACUS) every 15 minutes. More frequent interval scans can be employed to 

support NOAA's warning programs, including the tracking of tropical and subtropical cyclones. 

Government agencies and the private sector have access to digital data transmissions directly 

from NOAAPORT, from NOAA’s Environmental Satellite Processing Center (ESPC), or 

directly from GOES. 

 The current series of GOES satellites provide satellite data generated from full resolution 

imager and sounder data. Imagery at 1 and 4 and 8 km resolution is available for daytime and 

nighttime applications. The increased resolution of the satellite imagery is a vast improvement 

from previous satellites. Visible data are available at 1 km, “shortwave” infrared (channel 2 

data) as well as the infrared channels 3, 4, and 5 are available at 4 km resolution. and Water 

vapor (channel 3) is available at 8 4 km resolution on GOES-11 East and West. 4 km resolution 

on GOES-13. Channel 2 (Shortwave IR) data are valuable for the detection of low clouds, fog, 

stratus, and surface hot spots. channel 5 data, available on GOES-11, in combination with data 

from channels 2 and/or 4 are useful for detecting volcanic ash in the atmosphere. On GOES-13

East, channel 6 is a 13.3 μm band at 8 km that is useful in the detection of CO2. Channel 6 

improves the measurement of the height of clouds, derived winds and volcanic ash, thus 

improving computer model forecasts and ash warnings to the aviation community. The digital 

data may be enhanced to emphasize different features as desired. A suite of digital data and 

environmental products is available to users in the National Weather Service (NWS); the 

National Environmental Satellite, Data, and Information Service (NESDIS); other Federal 

agencies; the academic community; and many private agencies, both national and international. 

These data are made available through NOAAPORT, from ESPC, the Internet, and other means 

such as local networks. 

 7.1.1.1. GOES-13 East. GOES-13, launched May 24, 2006, supports the GOESEast is stationed at 75W and serves NOAA operations, to include the NHC, other Federal 
7-2 

agencies, and the private sector. Various imager channels at higher resolutions are being utilized 

to monitor the intensification and movement of tropical cyclones over the Atlantic Ocean and a 

portion of the East Pacific. In particular, greater detail in the imagery facilitates tropical cyclone 

monitoring and analysis, and the use of the GOES imager channel 2 has vastly improved the 

detection of low-level circulation centers at night to assist in storm positioning. Retrievals from 

the GOES sounder are being incorporated into NCEP's numerical models to improve model 

output. In addition, sounder data are being exploited to generate derived product imagery such 

as total precipitable water, atmospheric stability indices, surface temperatures and cloud heights. 

 During the 1996 hurricane season, NESDIS instituted a specialized GOES-East 

sounder schedule consisting of four sectors covering distinct areas of the Atlantic Ocean. Of the 

four sounder sectors, the CONUS sector is scanned every hour and covers the northern Gulf of 

Mexico and the east coast of the United States. During routine scanning operations, of the other 

3 sounder sectors (the Gulf of Mexico, North Atlantic, and the East Caribbean) the Gulf of 

Mexico sector is designated as the “primary OCONUS” (off CONUS) sector and is scanned 4 

times in a 6 hour period, while the other two sectors are only scanned once in every 6 hour 

period. Event driven, this “primary OCONUS” sounder sector can be changed by the NHC. The 

"primary" OCONUS sector provides frequent scans over the area of interest to generate vertical 

profiles of temperature and moisture, and additional derived environmental products such as 

atmospheric winds. 

 7.1.1.2. GOES-11 West. GOES-11 was launched on May 3, 2000, and supports 

the GOES-West is stationed at 135W. The routine scanning mode of GOES-11 West provides 

coverage of the Northern and Southern Hemisphere eastern Pacific Ocean as well as the western 

United States. The GOES-West satellite also supports the missions of both the NHC and the 

CPHC, and provides coverage of developing tropical cyclones over the East and Central Pacific. 

The DOD and other Federal agencies are also supported. 

 During the 2008 Central Pacific hurricane season, NESDIS instituted a 

specialized GOES-West sounder schedule consisting of additional Hawaii sectors. During 

routine operation, the GOES-West sounder scans two Hawaii and four North Pacific sectors. To 

aid in the surveillance and input of additional sounder data into hurricane models, the Central 

Pacific Hurricane Sector (CPHC) can request an alternate GOES-West sounder schedule that 

replaces two North Pacific sectors with two Hawaii sectors, allowing for four Hawaii sector 

scans and two North Pacific sector scans in a six-hour period. 

 7.1.1.3. GOES-12. GOES-12 was launched on July 23, 2001, and was operating 

as the GOES-East satellite until April 14, 2010. On April 26, 2010, GOES-12 began to be moved 

to its new station at 60° West, and is operating at that location in support of GEOSS in the 

Americas providing imager and sounder coverage to South America and surrounding areas. 

GOES-12 provides one imager scan every 15 minutes for the full South American continent, and 

a sounder scan every four hours. Data from GOES-12 is not processed at NESDIS. 

 7.1.1.4. GOES-N Series. The GOES-N Series will be used to continue and 

enhance the environmental monitoring and communications functions of the GOES-I thru M 

(GOES-8 thru 12) series of NOAA operational spacecraft. GOES-13, the first in the GOES-N 
7-3 

series, was designed with a different spacecraft bus than the previous GOES series, and contains 

larger power cells. This design results in the increased accuracy in navigation and instrument 

radiometrics, and the operation of the imager and sounder through the satellite “eclipse” season. 

GOES-O and GOES-P were also procured as part of the GOES-N series contract. GOES-O was 

launched on June 27, 2009 and renamed GOES-14; GOES-P was launched on March 4, 2010 

and was renamed GOES-15. 

 7.1.1.5. GOES-14. GOES-14 was launched on June 27, 2009. GOES-14 is the 

spare GOES located at 105° West and is ready to back-up GOES-13 or GOES-11. new GOESEast satellite as of September 12, 2012. 

 7.1.1.6. GOES-15. GOES-15 was launched on March 4, 2010. GOES-15 is the 

last of the GOES N series of satellites and will be used as standby. is currently the operational 

GOES-West satellite. 

7.1.2. EUMETSAT Meteosat Geostationary Satellites. Meteosat-9, launched 

December 21, 2005, and stationed at the Prime Meridian (0o), replaced Meteosat-8, which is 

stationed at 9.5o East, on April 11, 2007. It provides vital coverage of developing tropical waves 

off the African Coast and eastern Atlantic Ocean. Conventionally, the full disk IR, visible (VIS), 

and water vapor imagery have a 3 km resolution whereas a specialized VIS sector provides a 

maximum 1 km resolution. This visible sector has a limited scan, and will shift from the West 

Indian Ocean to the East Atlantic Ocean from 14:00 UTC to 01:00 UTC every day during 

hurricane season. This shift will ensure interests monitoring for tropical activity in the North 

Indian Ocean (Meteo-France) as well as the East Atlantic (NHC) will be satisfied. The digital 

data are transmitted to NESDIS and NCEP at the NOAA Science Center (NSC) in Camp 

Springs, MD, every 15 minutes. They are also available to the NHC and the Storm Prediction 

Center (SPC) through an encrypted DOMestic SATellite (DOMSAT) relay and through direct 

transmission from ESPC. Meteosat-7, launched September 2, 1997, provides coverage for the 

monitoring of Indian Ocean tropical cyclone formation and development while stationed at 57° 

East, with Meteosat-6 at 67° East in standby status. 

In December 1995, EUMETSAT, the program administrator, began encrypting digital 

Meteosat data 24 hours per day to regulate use within Europe. Based on international data policy 

agreements, U.S. non-government users are allowed access via a domestic satellite to nonencrypted Meteosat data 4 times per day at synoptic times; at other times, the data are encrypted. 

Hence, if quarter-hourly transmissions are required to support operational requirements, it is 

necessary for users to register with EUMETSAT to acquire decryption devices for installation at 

their local site (NOAA/DOD and other U.S. government agencies are registered). 

7.1.3. MTSAT-1R. The Multifunctional Transport Satellite-1 Replacement (MTSAT1R) was launched for the Japanese Meteorological Agency (JMA) on February 26, 2005. 

MTSAT-1R is located at 140° East, covering the West Pacific Ocean, East Asia, and the East 

Indian Ocean. MTSAT-1R is similar to GOES as it carries a 5-channel imager (one visible 

channel at 1 km plus four IR channels at 5 km, to include a new low-light IR channel). MTSAT1R provides imagery for the Northern Hemisphere every 30 minutes, and JMA makes the data 

available to 27 countries and territories in the region. Data from MTSAT-1R is available to 
7-4 

CONUS users via the DOMSAT or directly from ESPC and available to Pacific OCONUS users 

directly via downlinks in Hawaii and Guam. 

7.1.4. MTSAT-2. MTSAT-2 was launched on February 18, 2006 and replaced 

MTSAT-1R on July 1, 2010. The transportation and communication functions of MTSAT-1R 

will continue to be utilized after July 1, 2010, as MTSAT-1R becomes secondary. MTSAT-2 

carries a 5-channel imager with data downlink through the High Resolution Picture Transmission 

(HRPT) service. NOAA obtains the HRPT through the current downlink and corresponding 

DOMSAT uplink in Keana Point, Hawaii. MTSAT-2 is stationed at 145° East, and provides 

coverage for the monitoring of tropical cyclone formation and development for the West Pacific 

Ocean, East Asia, and the East Indian Ocean. 

7.1.5. COMS. The Communication, Ocean and Meteorology Satellite (COMS) is the 

first operational weather and ocean satellite from The Republic of Korea. COMS was developed 

by the Korean Astronomical Research Institute (KARI) through contract with EADS Astrium, 

and carries a 5 channel imager similar to the image on board MTSAT-1R and GOES. The 

Korean Meteorological Administration (KMA) will operate COMS through its National 

Meteorological Satellite Center (NSMC) with coverage of the West Pacific and East Indian 

oceans. COMS’s launch occurred on June 26, 2010, and operates at 128.2° East. 

7.1.6. Initial Joint Polar System (IJPS). Two primary operational polar orbiting 

satellites, NOAA’s NOAA-19 and EUMETSAT’s Metop-A, provide image coverage four times 

a day over a respective area in 6 spectral channels (however only 5 channels can be supported at 

one time; channel switching is used to support the 6th channel). These satellites cross the U.S. 

twice per day at 12-hour intervals for each geographical area near the Equatorial crossing times 

listed in Table 7-2. NOAA-19 and Metop-A provide the same capabilities as previous NOAA 

satellites, except that the Advanced Microwave Sounding Unit–B (AMSU-B) sensor flown 

aboard NOAA-17 and previous polar orbiters has been replaced by the Microwave Humidity 

Sounder (MHS) on NOAA-19. Data are available via direct readout—high-resolution picture 

transmission (HRPT) or automatic picture transmission (APT)—or via central processing. Data 

from the Advanced Very High Resolution Radiometer (AVHRR) on NOAA-19 and the 

corresponding Visible Infrared Imaging Radiometer (VIIRS) on board Metop-A are available on 

a limited basis through the GOES distribution system (Figure 7-1). The Air Force Weather 

Agency (AFWA), Offutt AFB, NE, receives global data from the Advanced Scatterometer 

(ASCAT) on board Metop-A direct from central readout sites on a pass-by-pass basis. The 

Command and Data Acquisition (CDA) stations at Fairbanks, AK, and Wallops, VA, acquire 

recorded global area coverage data sub-sampled to a 4 km spatial resolution, and then route the 

data to NESDIS computer facilities in Suitland, MD, where the data are processed and 

distributed to the NOAA, the DOD, and private communities. Ground equipment installed at 

various NWS regions including Kansas City, Miami (NHC), and Monterey enable direct readout 

and data processing of 1.1 km resolution AVHRR and VIIRS data from NOAA-19 and Metop-A. 

The high resolution polar data and products generated at NHC complement other satellite data 

sources to support tropical mission objectives. 

7.1.7. Non-NOAA Satellites. NOAA uses dedicated ground support systems to ingest 

and process data from select Non-NOAA satellite systems for use in operational forecasting and 
7-5 

tropical cyclone analysis. These include data from the NASA Earth Observing System (EOS) 

satellites: Terra, Aqua, and Aura; CORIOLIS from the Department of Defense; Jason-2 from the 

joint NOAA, NASA, CNES, and EUMETSAT; and Envisat from ESA. These satellites employ 

multiple infrared and microwave radiometers as well as active scatterometers to assess 

environmental features on the ocean surface. NOAA considers these datasets non-operational, 

and obtains the data on a best effort basis. 

7.1.8. Oceansat-2. Oceansat-2 is an Indian satellite, launched September 23, 2009, by 

the Indian Space Research Organisation (ISRO). Oceansat-2 is designed to study surface winds 

and ocean surface strata as well as other oceanic and atmospheric properties. Oceansat-2 is 

currently completing calibration and validation phase for certification. Oceansat-2 carries two 

payloads for ocean related studies, Ocean Colour Monitor (OCM) and Ku-band pencil-beam 

Scanning Scatterometer (SCAT). SCAT will be used to determine ocean surface level wind 

vectors through estimation of radar backscatter. SCAT will provide valuable ocean surface wind 

vector data for monitoring tropical cyclone formation and development, especially since the loss 

of QuikScat on November 23, 2009. 

Figure 7-1. The GOES Satellite System

7.2. National Weather Service (NWS) Support.
7-6 

7.2.1. Station Contacts. The GOES imagery is available in support of the surveillance 

of tropical and subtropical cyclones at specific NWS offices. Satellite meteorologists can be 

contacted at these offices; telephone numbers are in Appendix I. 

7.2.2. Products. Satellite-related products are listed in Chapter 3, Table 3-5, “Summary 

of Products and their Associated WMO Header.” 

7.2.2.1. Tropical Weather Discussions. NHC issues these discussions four times 

a day based on satellite imagery, meteorological analysis, weather observations and radar. They 

describe significant features and significant weather areas for the Gulf of Mexico, the Caribbean, 

and between the equator and 32N in both the Atlantic and eastern Pacific east of 140W. 

7.2.2.2. Satellite Interpretation Messages. CPHC issues these discussions four 

times a day to describe synoptic features and significant weather areas in the vicinity of the 

Hawaiian Islands. WFO Guam issues these discussions two times a day to describe synoptic 

features and significant weather over the Micronesian waters. 

7.3 NESDIS Satellite Analysis Branch (SAB). The SAB operates 24 hours a day to provide 

satellite support to the HPC/OPC, NHC, CPHC, JTWC, and other worldwide users. In addition 

to providing high quality imagery from geostationary and polar-orbiting satellites and 

coordinating the execution of GOES Rapid Scan Operations (RSO) requests, SAB provides 

pertinent information on global tropical cyclone development, including location and intensity 

analysis based on the Dvorak technique (Table 7-1). For numerical model input and forecasting 

applications, data from high density cloud motion wind vectors, high density water vapor wind 

vectors, four layers of derived precipitable water from sounder moisture retrievals, and tropical 

rainfall estimates are provided to HPC and NHC. In addition, estimates of cumulative rainfall 

expected over coastal areas derived using the Ensemble Tropical Rainfall Potential (eTRaP) 

methodology are provided for tropical storms within 24 hours of landfall and posted to a web site 

in support of CPHC, HPC, NHC, forecast offices in U.S. territories, and international customers. 

Telephone numbers for the SAB are located in Appendix I. 

Table 7-1. Communications Headings for SAB Dvorak Analysis Products

WMO HEADING OCEANIC AREA TYPE OF DATA 

TXST20-21 KNES South Atlantic Ocean VIS/IR 

7.4. Air Force Support and the Defense Meteorological Satellite Program (DMSP). Data 

covering the National Hurricane Operations Plan areas of interest are received centrally at the 

Air Force Weather Agency (AFWA) and distributed to the Air Force’s Operational Weather 

Squadrons (OWS) and the Navy’s Fleet Numerical Meteorology and Oceanography Center 

(FNMOC) at Monterey, CA. Satellite data covering the Central Pacific area are received at or 

shipped to the 17th OWS Meteorological Satellite Operations (SATOPS) Flight (17 OWS/WXJ), 

Joint Typhoon Warning Center, Pearl Harbor, HI. The 17 OWS/WXJ uses all available 

meteorological satellite data when providing fix and or intensity information to Central Pacific 

Hurricane Center forecasters. 
7-7 

7.4.1. Central Pacific Surveillance. The 17 OWS/WXJ (JTWC Satellite Operations) 

will provide, resources permitting, fix and intensity information to the CPHC on systems upon 

request. 

7.5. Satellites and Satellite Data Availability for the Current Hurricane Season. Table 7-

2 lists satellite capabilities for the current hurricane season. 

7.6. Current Intensity and Tropical Classification Number using the Dvorak Technique.

The current intensity (C.I.) number relates directly to the intensity of the storm. The empirical 

relationship between the C.I. number and a storm's wind speed is shown in Table 7-3. The C.I. 

number is the same as the tropical classification number (T-number) during the development 

stages of a tropical cyclone but is held higher than the T-number while a cyclone is weakening. 

This is done because a lag is often observed between the time a storm pattern indicates 

weakening has begun and the time when the storm's intensity decreases. An added benefit of this 

rule is the stability it adds to the analysis when short-period fluctuations in the cloud pattern 

occur. In practice, the C.I. number is not lowered until the T-number has shown weakening for 

12 hours or more. 

Table 7-2. Satellite and Satellite Data Availability for the Current Hurricane Season

SATELLITE TYPE OF 

DATA SCAN TIME PRODUCTS 

GOES-12 

at 60oW 

(supporting 

South America) 

GOES-11 

at 135°W 

GOES-13 

at 75°W 

GOES-14 

(on-orbit storage 

at 105°W) 

GOES-15 

(post-launch 

testing at 90°W) 

Multispectral 

Imager and 

Sounder; 5 

Channels for 

Imager; 19 

Channels for 

Sounder (not 

operational for 

GOES-10) 

GOES-12 is providing 15 

minute imager data and hourly 

sounder data covering South 

America 

GOES-11 East and GOES-13

West: Every 30 min, in 

Routine Scan Mode, provides 

3 sectors with prescribed 

coverages: Northern 

Hemisphere (NH) or Extended 

NH; CONUS or PACUS; and 

Southern Hemisphere. 

Exception is transmission of 

full disk every 3 hours. 

(Available Rapid Scan 

Operations yield increased 

transmissions to 7.5 minute 

intervals to capture rapidly 

changing, dynamic weather 

events). 

1. 1, 2, 4, and 8 km resolution visible 

standard sectors. 

2. 4 km equivalent resolution IR sectors. 

3. Equivalent and full resolution IR 

enhanced imagery. 

4. Full disk IR every 3 hours. 

5. 8 4 km water vapor sectors. (4 km on 

GOES-12) 

6. Quantitative precipitation estimates; high 

density cloud and water vapor motion wind 

vectors; and experimental visible and 

sounder winds. 

7. Operational moisture sounder data 

(precipitable water) in four levels for 

inclusion in NCEP numerical models. Other 

sounder products including gradient winds, 

vertical temperature and moisture profiles, 

mid-level winds, and derived product 

imagery (precipitable water, lifted index, and 

surface skin temperature). 

8. Tropical storm monitoring and derivation 

of intensity analysis. 

9. Volcanic ash monitoring and 

dissemination of Volcanic Ash Advisory 

Statements. 

10. Daily northern hemisphere snow cover 

analysis. 

11. Twice daily fire and smoke analysis over 

specific areas within CONUS. 
7-8 

Table 7-2 (continued). Satellite and Satellite Data Availability for the Current Hurricane Season

SATELLITE TYPE OF 

DATA LOCAL TIME PRODUCTS 

METEOSAT-9 

at 0° (Prime 

Meridian) 

METEOSAT-8 

at 9.5°E 

METEOSAT-7 

at 57°E 

Multi-spectral 

Spin-Scan 

Radiometer 

(SEVIRI) and 

High 

Resolution 

Visible (HRV) 

SEVIRI: Full disk image 

every 15 minutes. 

HRV: Sector scan to move 

with local noon. 

1. 1 km resolution digital VIS imagery 

(HRV); 3 km resolution digital IR imagery 

(SEVIRI. 

2. 3 km resolution VIS and IR WEFAX 

imagery. 

3. 3 km water vapor imagery. 

4. Tropical storm monitoring and derivation 

of intensity analysis. 

5. Volcanic ash detection and analysis. 

MTSAT-1R 

at 140°E 

MTSAT-2 

at 145°E

Multi-band 

imager (Visible 

plus four IR 

channels)

Hourly Full disk and two 

Northern Hemisphere scans 

per hour, with special 

“quadrant” scans four per 

hour.

1. 1 km resolution digital VIS imagery 

2. 5 km resolution digital IR imagery and 

water vapor 

4. Tropical storm monitoring and intensity 

analysis. 

5. Volcanic ash detection and analysis 

TRMM (NASA 

Tropical Rainfall 

Measuring 

Mission) 

85 and 37 GHz 

Microwave 

Fluctuates from 35°N to 35°S 1. 15 km resolution microwave coverage of 

the tropics from 35°S to 35°N. 

2. Microwave analysis of 85 and 37 GHz 

radiance composited passes. 

3. Brightness temperature products of the 85 

and 37 GHz horizontal and vertical 

polarization. Derived rain-rate products.

MetOp-A 

NOAA-19 

NOAA-18 

secondary 

NOAA-17 

backup 

NOAA-16 

secondary 

NOAA-15 

secondary 

AVHRR; GAC 

and LAC 

(recorded); 

HRPT (direct); 

AMSU-A; 

AMSU-B (N17); MHS (N19); HIRS 

VIIRS 1 km 

global 

Local Crossing Times: 

0931D1

/2131A2

0156D/1343A 

1. 1 km resolution HRPT and Local Area 

Coverage (LAC) data. 

2. 4 km resolution APT and Global Area 

Coverage (GAC) data. 

3. Mapped imagery. 

4. Unmapped imagery (all data types) at 

DMSP sites. 

5. Sea-surface temperature analysis. 

6. Soundings. 

7. Moisture profiles. 

8. Remapped GAC sectors. 

9. Sounding-derived products--total 

precipitable water, rain rate, and surface 

winds under sounding 

10. Daily northern hemisphere snow cover 

analysis. 

11. Twice daily fire and smoke analysis over 

specific areas within CONUS. 

12. AMSU based tropical cyclone intensity 

estimates. 

1

 D - descending 

2

 A - ascending 
7-9 

Table 7-2 (continued). Satellite and Satellite Data Availability for the Current Hurricane Season

SATELLITE TYPE OF DATA SCAN TIME PRODUCTS 

DMSP F-13 

Tactical 

DMSP F-14 

Tactical 

DMSP F-15 

Secondary 

DMSP F-16 

Secondary 

DMSP F-17 Ops 

DMSP F-18 Ops 

OLS Imagery (recorded and 

direct), SSM/I, SSM/T-1 

OLS Imagery (recorded and 

direct), SSM/I, SSM/T-1 

(inop), SSM/T-2 

OLS Imagery (recorded and 

direct), SSM/I, SSM/T-1, 

SSM/T-2 

OLS Imagery (recorded and 

direct), SSM/IS 

OLS Imagery (recorded and 

direct), SSM/IS 

OLS Imagery (recorded and 

direct), SSM/IS 

0543D1

/1743A2

0424D/1557A 

0841D/2041A 

0732D/1905A 

0528D/1728A 

0801D/2001A 

Note: Times are 

accurate to +/- 5 

minutes 

1. 0.3 nm (regional) and 1.5 nm (global) 

resolution (visual and infrared) imagery 

available via stored data recovery through 

AFWA. 

2. Regional coverage at 0.3 nm and 1.5 nm 

resolution (visual and infrared) imagery 

available from numerous DOD tactical 

terminals. 

3. SSM/T-1, SSM/T-2, SSM/I, and SSM/IS 

data transmitted to NESDIS and FNMOC 

from AFWA. 

1

 D - descending 

2

 A - ascending 

Table 7-3. The Dvorak Technique: The Empirical Relationship* between the C.I. Number and the 

Maximum Wind Speed and the Relationship between the T-Number and the Minimum Sea-Level 

Pressure (SLP) 

C.I. NUMBER MAXIMUM 

WIND SPEED T-NUMBER MINIMUM SLP (Atlantic) 

MINIMUM SLP 

(NW Pacific) 

1 25 kt 1 

1.5 25 1.5 

2 30 2 1009 hPa 1000 hPa 

2.5 35 2.5 1005 997 

3 45 3 1000 991 

3.5 55 3.5 994 984 

4 65 4 987 976 

4.5 77 4.5 979 966 

5 90 5 970 954 

5.5 102 5.5 960 941 

6 115 6 948 927 

6.5 127 6.5 935 914 

7 140 7 921 898 

7.5 155 7.5 906 879 

8 170 8 890 858 

*Dvorak, V, 1984: Tropical Cyclone Intensity Analysis Using Satellite Data. NOAA Tech Report NESDIS 11, Wash., D.C. 

8-1 

CHAPTER 8 

SURFACE RADAR REPORTING

8.1. General. Radar observations of tropical cyclones will be made at Department of Defense 

(DOD), National Weather Service (NWS), and Federal Aviation Administration (FAA) Weather 

Surveillance Radar-1988 Doppler (WSR-88D) facilities. Participating radar sites are listed in 

Table 8-1. 

8.2. The WSR-88D. The WSR-88D is a computerized radar data collection and processing 

system. The design and implementation of the WSR-88D was a joint effort of the DOD, NWS, 

and FAA, and the utilization of the radar continues to be governed by tri-agency agreement. The 

WSR-88D is an S-band (10-cm), coherent radar, with a nominal beam width of 1 degree. The 

maximum data ranges are 248 nm (reflectivity) and 124 nm (velocity), although velocity data out 

to 162 nm can be obtained from radars using “super-resolution.” Radar scanning strategies are 

selectable, using predetermined volume coverage patterns (VCPs). The VCP in use depends 

upon which weather phenomena are under surveillance. Once the radar data has been collected, 

it is processed automatically at the radar site by a suite of algorithms which provide graphical 

products for forecaster use. NHC, as an external user, obtains these products through a network 

connection. CPHC obtains products directly from four WSR-88Ds in Hawaii operated by the 

NWS Weather Forecast Office in Honolulu. 

8.3. Procedures. As a tropical cyclone approaches, NHC uses the WSR-88D to perform 

radar center-fixing and to obtain other diagnostic information. Therefore, it is important to 

optimize WSR-88D performance for tropical cyclones and to allow other users, especially the 

NHC, access to radar products in the area of landfall. Most of the changes must be issued 

through the Master System Control Function (MSCF), Radar Product Generator (RPG) Human 

Computer Interface (HCI). To facilitate this process, NHC in cooperation with the Radar 

Operations Center (ROC) has developed an operations plan for use during tropical cyclone 

events. The current WSR-88D Tropical Cyclone Operations Plan is available as a sub-link to the 

National Hurricane Operations Plan on the OFCM web site at 

http://www.ofcm.gov/homepage/text/pubs.htm. It is also available via fax from the ROC Hotline 

(1-800-643-3363). 

8.3.1. Radar Observation Requirements, WSR-88D. Chief among the requirements is 

the appropriate display of hurricane-force winds. Changes must be made at the radar site, guided 

by the WSR-88D Tropical Cyclone Operations Plan, in order to deal effectively with hurricane 

conditions. The physical characteristics of the tropical cyclone are best represented by use of the 

precipitation mode. Choice of VCP may significantly enhance (or degrade) collection of 

velocity data. (See WSR-88D Tropical Cyclone Operations Plan for further information.) Radar 

characteristics of hurricanes are given in Federal Meteorological Handbook Number 11 (FMH11), Part B, Chapter 9. Further discussion of product usage appears in FMH-11, Part D, Unit 

Description and Operational Applications. A recommended product list appears in FMH-11 Part 

D, Application versus Product Table 4-3. 
8-2 

Table 8-1. Participating WSR-88D Radar Stations1

NWS Radars 

U.S. Gulf and Atlantic Coasts 

NWS Radars 

U.S. Southwest 

FAA 

Radars DOD Radars 

Albany, NY 

Atlanta, GA 

Binghamton, NY 

Birmingham, AL 

Boston, MA 

Brandon/Jackson, MS 

Brownsville, TX 

Caribou, ME 

Charleston, SC 

Columbia, SC 

Corpus Christi, TX 

Ft. Worth, TX 

Greer, SC 

Houston, TX 

Huntsville/Hytop, AL 

Jacksonville, FL 

Key West, FL 

Lake Charles, LA 

Melbourne, FL 

Miami, FL 

Mobile, AL 

Morehead City, NC 

New Orleans/Baton Rouge, LA 

New York City, NY 

Philadelphia, PA 

Portland, ME 

Raleigh/Durham, NC 

Roanoke, VA 

San Antonio, TX 

Shreveport, LA 

State College, PA 

Sterling, VA 

Tallahassee, FL 

Tampa, FL 

Wakefield, VA 

Wilmington, NC 

Los Angeles, CA 

Phoenix, AZ 

San Diego, CA 

Santa Ana Mtns, CA 

Tucson, AZ 

Yuma, AZ 

Molokai, HI 

Kohala, HI 

San Juan, PR 

South Hawaii, HI 

South Kauai, HI 

Andersen AFB, Guam 

Columbus AFB, MS 

Dover AFB, DE 

Eglin AFB, FL 

Fort Hood, TX 

Fort Polk, LA 

Fort Rucker, AL 

Maxwell AFB, AL 

Moody AFB, GA 

Robins AFB, GA 

 

1

The criterion for selection is that the radar site is located within approximately 124 nm (legacy maximum velocity 

range) of the coastline. 
8-3 

8.3.2. Central Region Report. The following fix definitions and criteria are used in 

reporting tropical cyclone radar observations: 

 If the central region of a storm is defined by an identifiable circular, or nearly 

circular, wall cloud with an echo-free center, the fix (the geometric center) is reported 

as an "EYE". 

 If the central region is recognizable, but not well-defined by a wall cloud (as in the 

case of a tropical storm), it is reported as a “CENTER." 

 When the eye or center is only occasionally recognizable or some other central region 

uncertainty exists, the eye or center is reported as "PSBL EYE" or "PSBL 

CENTER."

 Remarks stating the degree of confidence will be included and will be classified as 

either "good," "fair," or "poor." If an eye is present, a "good" fix is reported when the 

eye is symmetrical--virtually surrounded by wall cloud; a "poor" fix is reported when 

the eye is asymmetrical--less than 50 percent surrounded by wall cloud; a "fair" fix is 

reported to express a degree of confidence between "good" and "poor." Note that a 

partial eyewall may be the result of excessive range from the radar, or represent the 

true structure of the system. Doppler velocities will, in general, increase confidence 

in the center position and, if available, should always be examined prior to 

establishing a fix. 

8.3.3. Transmission of Radar Reports. When the tropical cyclone is within 200 nm of 

a WSR-88D, and the center fix is considered reliable, the appropriate tropical cyclone warning 

center (NHC or CPHC) may issue a tropical cyclone position estimate (AWIPS category TCE) 

between 2-hourly intermediate advisories. Note that although the issuance of this product 

depends upon the quality of the radar fix, other data sources such as aircraft reconnaissance may 

be blended with the radar estimate to obtain a position. Thus, a radar position based on 

particular radar may appear to disagree with the TCE position, but has in fact been taken into 

consideration. 

 In the case of communications failure, and the event that NHC cannot obtain the 

necessary radar data, the local NWS Weather Forecast Office may be called upon to 

estimate the radar position and render qualitative assessment of the circulation. 

 Other radar facilities not having weather transmission capability but wishing to 

provide information deemed important, should call the nearest NWS Weather 

Forecast Office or the NHC. 

9-1 

CHAPTER 9 

NATIONAL DATA BUOY CAPABILITIES AND REQUIREMENTS

9.1. General.

9.1.1. Automated Reporting Stations. The National Data Buoy Center (NDBC) 

maintains automated reporting stations in the coastal and deep ocean areas of the Gulf of 

Mexico, the Atlantic and Pacific Oceans, and in the Great Lakes. These data acquisition systems 

collect real-time meteorological and oceanographic measurements for operational and research 

purposes. Moored buoys are deployed in the Southern Gulf of Mexico, the Caribbean and the 

Atlantic Ocean east of the Lesser Antilles for the primary purpose of supporting National 

Hurricane Center operations. NDBC also quality controls and releases meteorological data from 

the National Ocean Service Water Level Observing Network and from moorings and coastal 

stations operated by cooperating Regional Ocean Observing Systems. The NDBC website at 

http://www.ndbc.noaa.gov/ provides locations, latest operating status, and site-specific 

information for NDBC stations and provides links to details on partner organization stations. 

Specific questions may be addressed to NDBC Data Management and Communications Branch, 

Stennis Space Center, Mississippi 39529-6000, phone 228-688-2835. 

9.1.2. Data Acquisition. Moored buoy and Coastal-Marine Automated Network (CMAN) stations routinely acquire, store, and transmit data every hour; a few selected stations 

report more frequently. Data obtained operationally include sea level pressure, wind speed and 

direction, peak wind, and air temperature. Sea surface temperature and wave spectra data are 

measured by all moored buoys and a limited number of C-MAN stations. Relative humidity is 

measured at several stations. Ocean currents and salinity are measured at a few coastal stations. 

 NDBC acquires, encodes, and distributes data from partner organizations via NWS 

dissemination systems. Data from partner organizations pass through NDBC data quality control 

procedures prior to NWS dissemination. Frequency and timeliness of transmissions from these 

stations varies by organization. 

9.1.3. Drifting Buoys. 

9.1.3.1. NDBC. NDBC is capable of acquiring, preparing, and deploying drifting 

buoys; however, an operational drifting buoy requirement has not been identified or funded. 

9.1.3.2. Navy. Since 1998, the Naval Oceanographic Office (NAVOCEANO) has 

deployed meteorological drifting buoys to report surface meteorological and oceanographic 

measurements, for operational purposes, as tropical systems move through data sparse regions 

tracking toward the U.S. East Coast. Additionally, Navy drifting buoys have been deployed in 

the Intertropical Convergence Zone (ITCZ). The drifting buoy measurements, which are 

available to tropical forecasters, provide invaluable input for defining tropical storm movement 

and intensity, improve forecast model initialization, and give tropical forecasters a much better 

sense of storm characteristics and track as they approach the fleet concentration areas of 
9-2 

Jacksonville, FL, and Norfolk, VA. Drifting buoys typically have a life span of 1 to 2 years, and 

the data are available through the NAVOCEANO homepage and through standard World 

Meteorological Organization (WMO) data sources. 

NAVOCEANO acquires, prepares, and deploys drifting meteorological buoys 

based on operational requirements identified by the Commander, U.S. Atlantic Fleet 

(COMLANTFLT). Currently, COMLANTFLT has identified the Navy’s drifting buoy support 

as a standing requirement to support fleet safety, assist in fleet sortie decisions, and enhance 

tropical weather preparedness. 

9.2. Requests for Drifting Buoy Deployment. Drifting buoy deployments should be 

coordinated through the Department of Commerce (DOC), National Oceanic and Atmospheric 

Administration (NOAA). Deployments will be requested through the Office of the Federal 

Coordinator for Meteorology (OFCM) to HQ Air Force Reserve Command (AFRC). 

Deployments in advance of a U.S. land-threatening hurricane require a 36- to 48-hour 

notification.

9.2.1. CARCAH. CARCAH will issue, through the Tropical Cyclone Plan of the Day 

(TCPOD), an alert or outlook for drifting buoy deployment 48 hours before the planned 

deployment. Hard tasking for the deployment will be issued via the TCPOD at least 16 hours, 

plus flying time to the deployment location, before the event. 

9.2.2. Deployment of Buoys. DOC may request the deployment of a drifting buoy and 

subsurface float array with up to 40 elements at a distance of 200 to 400 nm from the storm 

center, depending on the dynamics of the storm system. DOC will ensure the buoys and missionrelated DOC personnel are delivered to AFRC. The specific DOC request for placement of the 

buoys will depend on several factors, including: 

 Characteristics of the storm, including size, intensity, and velocity. 

 Storm position relative to the coast and population centers. 

 Availability of aircraft and Loadmasters (LM) certified for buoy deployment. 

9.2.3. Deployment Position. The final deployment position will be provided before the 

flight crew briefing. An example of a possible buoy and float deployment pattern from the recent 

CLBAST Experiment is shown in Figure 9-1. 

9.3. Communications. Moored buoy and C-MAN data are transmitted via NOAA 

Geostationary Operational Environmental Satellite (GOES) to the National Environmental 

Satellite, Data, and Information Service (NESDIS) or via the Iridium satellite communication 

system and then are relayed to the NWS Telecommunications Gateway (NWSTG) for processing 

and dissemination. Data from partner organizations acquired by NDBC are relayed to the 

NWSTG for processing and dissemination. Moored buoy observations are formatted into the 

World Meteorological Organization (WMO) FM13 SHIP code. C-MAN and other partner 

organization coastal station data are formatted into C-MAN code, which is very similar to the 

WMO FM12 SYNOP code. Drifting buoys transmit data via NOAA’s Polar Orbiting 

Environmental Satellites (POES) to the U.S. Argos Global Processing Center, Largo, Maryland. 
9-3 

Service Argos processes and formats the data into WMO FM18 BUOY code. The messages are 

then routed to the NWSTG for distribution. The formats for WMO encoded messages may be 

found in the WMO Manual on Codes Volume One, WMO-No. 306.

Figure 9-1. Example Buoy and Float Deployment Pattern

10-1 

CHAPTER 10 

MARINE WEATHER BROADCASTS

10.1. General. The National Weather Service and the Department of Homeland Security’s 

United States Coast Guard (USCG) broadcast forecast products that include information on 

tropical cyclones issued by the National Hurricane Center and the Central Pacific Hurricane 

Center. The broadcast of these products supports the U.S. participation in the Global Maritime 

Distress and Safety System, which provides the communications support to the International 

Maritime Organization's (IMO) global search and rescue plan. 

10.2. Global Maritime Distress and Safety System (GMDSS). The goals of GMDSS are to 

provide more effective and efficient emergency and safety communications, and to disseminate 

maritime safety information to all ships on the world's oceans regardless of location or 

atmospheric conditions. These goals are defined in the International Convention for the Safety 

of Life at Sea (SOLAS) 1974, as amended. GMDSS is based upon a combination of satellite and 

terrestrial radio services and has changed international distress communications from being 

primarily ship-to-ship based to ship-to-shore (rescue coordination center) based. GMDSS 

provides for automatic distress alerting and locating, and requires ships to receive broadcasts of 

maritime safety information which could prevent a distress from happening in the first place. 

The NWS participates directly in the GMDSS by preparing weather forecasts and warnings for 

broadcast via two primary GMDSS systems--NAVTEX and Inmarsat-C SafetyNET. 

10.2.1. NAVTEX. NAVTEX is an international, automated system for instantly 

distributing maritime navigational warnings, weather forecasts and warnings, search and rescue 

notices, and similar information to ships. It has been designated by the IMO as the primary 

means for transmitting coastal urgent marine safety information to ships worldwide. NAVTEX 

is broadcast from the 12 USCG stations. Coverage is reasonably continuous along the east, west, 

and Gulf coasts of the United States, as well as the area around Kodiak, Alaska, Guam, and 

Puerto Rico. Typical NAVTEX transmissions range from 200-400 nm. 

10.2.2. SafetyNET. Satellite systems operated by Inmarsat Ltd. are an important element 

of the GMDSS. Inmarsat-C provides ship/shore, shore/ship, and ship/ship store-and-forward 

data and telex messaging; the capability for sending preformatted messages to a rescue 

coordination center; and the SafetyNET service. The Inmarsat-C SafetyNET service is a 

satellite-based worldwide maritime safety information broadcast service of high seas weather 

warnings, navigational warnings, radionavigation warnings, ice reports and warnings generated 

by USCG-conducted International Ice Patrol, and other information not provided by NAVTEX. 

10.3. Coastal Maritime Safety Broadcasts. In addition to NAVTEX, the USCG and other 

government agencies broadcast maritime safety information, using a variety of different radio 

systems to ensure coverage of different ocean areas for which the United States has 

responsibility and to ensure all ships of every size and nationality can receive this vital safety 

information. 
10-2 

10.3.1. VHF Marine Radio. The USCG broadcasts nearshore and storm warnings of 

interest to the mariner on VHF channel 22A (157.1 MHZ) following an initial call on the 

distress, safety, and calling channel 16 (156.8 MHZ). Broadcasts are made from over 200 sites, 

covering the coastal areas of the U.S., including the Great Lakes, major inland waterways, 

Puerto Rico, Alaska, Hawaii, and Guam. All ships in U.S. waters over 20 meters in length are 

required to monitor VHF channel 16 and must have radios capable of tuning to the VHF simplex 

channel 22A. Typical coverage is 25 nm offshore. 

10.3.2. Medium Frequency Radiotelephone (Voice). The USCG broadcasts offshore 

forecasts and storm warnings of interest to mariners on 2670 kHz, after first being announced on 

the distress, safety, and calling frequency 2182 kHz. 

10.3.3. NOAA Weather Radio. The NOAA Weather Radio network continually 

broadcasts coastal and marine forecasts on frequencies near 162 MHZ. Recorded voice 

broadcasts have largely been supplanted by a synthesized voice. The network provides nearcontinuous coverage of the coastal U.S., Great Lakes, Hawaii, Guam, Commonwealth of the 

Northern Mariana Islands, and the populated Alaska coastline. Typical coverage is 25 nm 

offshore. 

10.4. High Seas Broadcasts. NWS high seas weather forecasts and warnings are also 

available on the following high frequency (HF) broadcasts. 

10.4.1. HF Radiotelephone (Voice). Weather forecasts and warnings for high seas and 

offshore areas are broadcast over scheduled HF single sideband (SSB) radiotelephone channels 

from USCG communications stations using a very distinctive and recognizable computersynthesized voice. 

10.4.2. HF Radiofacsimile. The USCG broadcasts NWS high seas weather maps from 

five communications stations--Boston, MA (NMF); Point Reyes, CA (NMC); New Orleans, LA 

(NMG), Honolulu, HI (KVM-70) (a DOD station); and Kodiak, AK (NOJ). Limited satellite 

imagery, sea surface temperature maps, and text forecasts are also available. 

10.4.3. HF Radiotelex (HF SITOR). High seas forecasts in text format, recognized by 

the GMDSS, are broadcast over scheduled GMDSS HF narrow-band direct printing channels 

from USCG communications stations. Limited offshore forecasts are also available. 

10.4.4. WWV, WWVH HF Voice (Time Tick). Atlantic high seas warnings are 

broadcast at 7 and 8 minutes past the hour over WWV (Boulder, CO) on the following HF 

frequencies: 2.5, 5, 10, 15, and 20 MHZ; Pacific high seas warnings are broadcast at 9 minutes 

past the hour. Pacific high seas warnings are broadcast from 48-51 minutes past the hour over 

WWVH (Honolulu, HI) at 2.5, 5, 10, and 15 MHZ. These are the National Institute of Standards 

and Technology (NIST) standard time/frequency broadcasts. 
10-3 

10.5. Additional Information. Further information concerning these and other marine 

broadcasts, including schedules, frequencies, and links to products can be found at: 

 www.nws.noaa.gov/om/marine/home.htm

 http://www.navcen.uscg.gov/?pageName=maritimeTelecomms

In addition, the National Geospatial-Intelligence Agency (NGA), Publication 117, Radio 

Navigational Aids (http://msi.nga.mil/NGAPortal/MSI.portal; click on “Publications;” from 

Menu Options, select “Radio Navigational Aids”), contains detailed information on maritime 

safety information broadcasts within the U.S. and worldwide. 

11-1 

CHAPTER 11 

PUBLICITY

11.1. News Media Releases. News media releases, other than warnings and advisories, for the 

purpose of informing the public of the operational and research activities of the Departments of 

Commerce, Defense, and Transportation should reflect the joint effort of these agencies by 

giving due credit to the participation of other agencies. 

11.2. Distribution. Copies of these releases should be forwarded to the following agencies: 

 NOAA Office of Public Affairs 

Herbert C. Hoover Building 

14th and Constitution Avenue, N.W. 

Washington, DC 20230 

 Commander, Naval Meteorology and Oceanography Command 

1100 Balch Boulevard 

Stennis Space Center, MS 39522-3001 

 HQ Air Force Reserve Command (AFRC/PA) 

Robins AFB, GA 31093 

 Joint Staff Weather Officer 

The Joint Chiefs of Staff (J3/DDGO-ROD) 

Pentagon Room 2D-921G 

Washington, DC 20318-3000 

 Federal Aviation Administration (APA-310) 

800 Independence Avenue, S.W. 

Washington, DC 20591 

 Director, NOAA Aircraft Operations Center 

P.O. Box 6829 

MacDill AFB, FL 33608-0829 

 Federal Coordinator for Meteorology 

Suite 1500, 8455 Colesville Road 

Silver Spring, MD 20910 

A-1 

APPENDIX A

LOCAL NATIONAL WEATHER SERVICE (NWS) OFFICE PRODUCTS

A.1. General. This appendix briefly describes some of the products issued by local National 

Weather Service (NWS) offices which support the tropical cyclone forecasting and warning 

program. Additional details of all the products can be found in National Weather Service 

Instruction 10-601, located at http://www.weather.gov/directives. 

A.2. Products. 

 A.2.1. Hurricane/Typhoon Local Statements (HLS). WFOs with coastal county 

responsibilities and selected inland WFOs will issue these products which are very specific and 

designed to inform media, local decision makers, and the public on present and anticipated storm 

effects in their county warning area (CWA) and adjacent coastal waters. HLSs will add 

localized details to tropical cyclone center’s advisory releases and should not conflict with or 

repeat advisory information not directly applicable to the local office’s CWA. 

Coastal WFOs are defined as those having at least one county with significant tidal influences. 

Those are: 

EASTERN REGION SOUTHERN 

REGION WESTERN REGION PACIFIC REGION 

Caribou, ME 

Portland, ME 

Boston, MA 

New York City, NY 

Philadelphia, PA 

Baltimore, MD/ 

 Washington, DC 

Wakefield, VA 

Newport/ 

 Morehead City, 

NC 

Wilmington, NC 

Charleston, SC 

Brownsville, TX 

Corpus Christi, TX 

Houston/Galveston, 

TX 

Lake Charles, LA 

New Orleans, LA 

Mobile, AL 

Tallahassee, FL 

Tampa Bay, FL 

Miami, FL 

Key West, FL 

Melbourne, FL 

Jacksonville, FL 

San Juan, PR 

San Diego, CA 

Los Angeles/ 

 Oxnard, CA 

Honolulu, HI 

Guam 

WSO Pago Pago, 

 American Samoa 

 A.2.2. Extreme Wind Warning (EWW). Short duration warnings are issued by WFOs 

to protect lives and property. WFO forecasters issue short duration EWW products to provide 

the public with advance notice of the onset of extreme tropical cyclone winds, usually associated 

with the eyewall of a major (category 3 or higher) tropical cyclone. Extreme Wind Warnings 

inform the public of the need to take immediate shelter in an interior portion of a well-built 

structure due to the onset of extreme tropical cyclone winds. 
A-2 

 A.2.3. Post-Tropical Cyclone Reports (PSH). The PSH is the primary WFO post 

tropical cyclone product issued to the public to report and document local tropical cyclone 

impacts. The PSH product is intended to provide the NHC, NWS Headquarters, the media, the 

public, and emergency management officials with a record of peak tropical cyclone conditions. 

This data is then used to formulate other post-event reports, news articles and historical records. 
B-1 

APPENDIX B 

DEFINING POINTS FOR TROPICAL CYCLONE WATCHES/WARNINGS 

The coastal areas placed under tropical storm and hurricane/typhoon watches and warnings are 

described through the use of "breakpoints" or geographical positions. The National Weather 

Service (NWS) designates the locations along the U.S. East, Gulf, and California coasts, Puerto 

Rico, and Hawaii. Individual countries across the Caribbean, Central America, and South 

America provide coastal locations for their areas of responsibility to the NWS for the National 

Hurricane Center's use in tropical cyclone advisories when watches/warnings are issued by 

international partners. For graphical representations of the breakpoints, see 

http://www.nhc.noaa.gov/breakpoints_graphics.shtml. An additional source for breakpoint 

information is NWS Instruction 10-605, located at http://www.weather.gov/directives. 

C-1 

APPENDIX C

JOINT TYPHOON WARNING CENTER (JTWC) BULLETINS

Below are the abbreviated communications headers and titles for the products for which JTWC is 

responsible. A brief description of each product, to include scheduled transmission times, is 

available http://www.usno.navy.mil/JTWC/products-and-services-notice. 

ABIO10 PGTW Significant Weather Advisory, Indian Ocean 

ABPW10 PGTW Significant Weather Advisory, Western Pacific Ocean 

WTPN21-26 PGTW Tropical Cyclone Formation Alert, Northwest Pacific Ocean 

WTPN31-36 PGTW Tropical Cyclone Warning, Northwest Pacific Ocean 

WDPN31-36 PGTW Prognostic Reasoning Bulletin, Northwest Pacific Ocean 

WTIO21-25 PGTW Tropical Cyclone Formation Alert, North Indian Ocean 

WTIO31-35 PGTW Tropical Cyclone Warning, North Indian Ocean 

WTPS21-25 PGTW Tropical Cyclone Formation Alert, Southwest Pacific Ocean 

WTPS31-35 PGTW Tropical Cyclone Warning, Southwest Pacific Ocean 

WTXS21-26 PGTW Tropical Cyclone Formation Alert, South Indian Ocean 

WTXS31-36 PGTW Tropical Cyclone Warning, South Indian Ocean 

WTPN21-25 PHNC Tropical Cyclone Formation Alert, Northeast Pacific Ocean 

WTPN31-35 PHNC Tropical Cyclone Warning, Northeast Pacific Ocean 

FKPN31-35 PHNC Prognostic Reasoning Bulletin, Northeast Pacific Ocean 

WTPS21-25 PHNC Tropical Cyclone Formation Alert, Southeast Pacific Ocean 

WTPS31-35 PHNC Tropical Cyclone Warning, Southeast Pacific Ocean 

TPPN10-19 PGTW Tropical Cyclone Position and Intensity, Northwest Pacific Ocean 

TPIO10-19 PGTW Tropical Cyclone Position and Intensity, North Indian Ocean 

TPPS10-19 PGTW Tropical Cyclone Position and Intensity, Southwest Pacific Ocean 

TPXS10-19 PGTW Tropical Cyclone Position and Intensity, Southern Indian Ocean 

TPPZ01-05 PGTW Tropical Cyclone Position and Intensity, Central North Pacific 

Ocean

D-1 

APPENDIX D

FORMAT FOR NHOP/NWSOP FLIGHT INFORMATION FOR INTERNATIONAL 

AND DOMESTIC NOTAM ISSUANCE 

Flight information shall be sent to the NOTAM office via facsimile for dissemination as an 

International and Domestic NOTAM in the following format (Note: The request is made for a 

domestic NOTAM which will then automatically makes its way into the international NOTAM 

system):

HEADER 

Request a Domestic NOTAM be Issued 

A. Affected Center(s). This field will include all affected ARTCCs in 3-letter identifier 

format; e.g., ZNY, ZOA, ZAN. Synoptic track flights will probably utilize more than one 

ARTCC, and any adjacent ARTCC should be included when the flight track is within 100 

miles of the adjacent center’s airspace. Flights that are flying in the storm environment 

will utilize the ARTCC whose airspace is mostly affected. 

B. Start Time (YYMMDDZZZZ). For example, 0006011600. This time would correspond 

to the entry time on a reconnaissance track or time at the storm fix latitude/longitude. 

C. Ending Time (YYMMDDZZZZ). This would be the completion time of reconnaissance 

track or the time exiting the storm environment. 

E.* Text. This field is free form and should include the following information: route of 

flight for the mission portion (latitude/longitude, fixes, airways), type of activity (laser, 

dropsonde, etc.), frequency/location of deployment, broadcast frequencies, any other 

pertinent information that may concern other flights. Include a unit/agency phone 

number and point of contact for possible questions. 

F. Lower Altitude (during mission). Use “Surface” since the dropsonde is the “reason” for 

the NOTAM as much or more so than the aircraft altitude. 

G. Upper Altitude (during mission). For example, FL450. 

If only one altitude is to be used, then F and G may be combined. If altitude is going to 

vary throughout the mission, utilize “see text” and the information can be inserted there 

and the altitudes may be explained in field E. 

* Note that there is no paragraph “D”. It is reserved for FAA use.

NOTES: 

1. Only ICAO approved contractions may be used. 

2. Using this format will help ensure timely and accurate information dissemination. 

E-1 

APPENDIX E

SAFFIR-SIMPSON HURRICANE WIND SCALE

Saffir-Simpson Hurricane Wind Scale: The Saffir-Simpson Hurricane Wind Scale (SSHWS) is a 

scale on a 1 to 5 categorization based on the hurricane's intensity at the indicated time. The scale 

provides examples of the type of damages and impacts associated with winds of the indicated 

intensity. In general, damage rises by a factor of four for every category increase. The maximum 

sustained surface wind peak (peak 1-minute wind at the standard meteorological observation 

height of 10 m [33 ft] over unobstructed exposure) associated with the cyclone is the determining 

factor in the scale. (Note that sustained winds can be stronger in hilly or mountain terrain 

compared with that experienced over flat terrain). Details for the Atlantic and Eastern Pacific 

Hurricane Basins and Central Pacific Hurricane Basin regarding the SSHWS can be found at the 

web sites indicated below. 

Atlantic and Eastern Pacific Hurricane Basins: http://www.nhc.noaa.gov/aboutsshs.shtml. 

Central Pacific Hurricane Basin: http://www.prh.noaa.gov/cphc/pages/aboutsshs.php. 

APPENDIX F

OFFICIAL INTERAGENCY AGREEMENTS

The following enclosure is the Memorandum of Agreement (MOA) between the Air 

Force Reserve Command (AFRC) and the National Oceanic and Atmospheric Administration 

(NOAA), October 12, 2000. The purpose of this agreement is to establish policies, principles, 

and procedures under which the AFRC and NOAA provide aircraft weather reconnaissance and 

surveillance in support of NOAA’s tropical cyclone forecast, warning, and research missions. 

F-1 





G-1 

APPENDIX G 

RECCO, HDOB, AND TEMP DROP 

CODES, TABLES, AND REGULATIONS 

(Incorporated Change 1 on August 24, 2012 for Page G-14)
G-2 

Figure G-1. Reconnaissance Code Recording Form 
G-3 

Table G-1. Reconnaissance Code Tables 

TABLE 1 XXX 

222 Sec One Observation without radar 

capability 

555 Sec Three (intermediate) 

observation with or without radar 

capability 

777 Sec One Observation with radar 

capability 

TABLE 2 id 

0 No dew point capability/acft below 

10,000 meters 

1 No dew point capability/acft at or 

above 10,000 meters 

2 No dew point capability/acft below 

10,000 meters and flight lvl temp -

50°C or colder 

3 No dew point capability/acft at or 

above 10,000 meters and flight lvl 

temp -50°C or colder 

4 Dew point capability/acft below 

10,000 meters 

5 Dew point capability/acft at or above 

10,000 meters 

6 Dew point capability/acft below 

10,000 meters and flight lvl temp -

50°C or colder 

7 Dew point capability/acft at or above 

10,000 meters and flight lvl temp -

50°C or colder 

TABLE 3 Q 

0 0° -90° W Northern 

1 90° W - 180° Northern 

2 180° - 90° E Northern 

3 90° - 0° E Northern 

4 Not Used 

5 0° - 90° W Southern 

6 90° W - 180° Southern 

7 180° - 90° E Southern 

8 90° - 0° E Southern 

TABLE 4 B 

0 None 

1 Light turbulence 

2 Moderate turbulence in clear air, 

infrequent 

3 Moderate turbulence in clear air, 

frequent 

4 Moderate turbulence in cloud, 

infrequent 

5 Moderate turbulence in cloud, 

frequent 

6 Severe Turbulence in clear air, 

infrequent 

7 Severe Turbulence in clear air, 

frequent 

8 Severe Turbulence in cloud, 

infrequent 

9 Severe Turbulence in cloud, frequent 

TABLE 5 fc 

0 In the clear 

8 In and out of clouds 

9 In clouds all the time (continuous 

IMC) 

/ Impossible to determine due to 

darkness or other cause

TABLE 6 dt 

0 Spot of Wind 

1 Average wind 

/ No wind reported 

TABLE 7 da 

0 Winds obtained using doppler radar or 

inertial systems 

1 Winds obtained using other navigation 

equipment and/or techniques 

/ Navigator unable to determine or wind 

not compatible 

TABLE 8 w 

0 Clear 

1 Scattered (trace to 4/8 cloud coverage) 

2 Broken (5/8 to 7/8 cloud coverage) 

3 Overcast/undercast 

4 Fog, thick dust or haze 

5 Drizzle 

6 Rain (continuous or intermittent precip 

- from stratiform clouds) 

7 Snow or rain and snow mixed 

8 Shower(s) (continuous or intermittent 

precip - from cumuliform clouds) 

9 Thunderstorm(s) 

/ Unknown for any cause, including 

darkness 

TABLE 9 j 

0 Sea level pressure in whole millibars 

 (thousands fig if any omitted) 

1 Altitude 200 mb surface in geopotential 

decameters (thousands fig if any 

omitted) 

2 Altitude 850 mb surface in geopotential 

meters (thousands fig omitted) 

3 Altitude 700 mb surface in geopotential 

meters (thousands fig omitted) 

4 Altitude 500 mb surface in geopotential 

decameters 

5 Altitude 400 mb surface in geopotential 

decameters 

6 Altitude 300 mb surface in geopotential 

decameters 

7 Altitude 250 mb surface in geopotential 

decameters (thousands fig if any 

omitted) 

8 D - Value in geopotential decameters; if 

negative 500 is added to HHH 

9 Altitude 925 mb surface in geopotential 

meters 

/ No absolute altitude available or 

geopotential data not within ± 30 

meters/4 mb accuracy requirements 

TABLE 10 Ns 

0 No additional cloud layers (place 

holder) 

1 1 okta or less, but not zero 

(1/8 or less sky covered) 

2 2 oktas (or 2/8 of sky covered) 

3 3 oktas (or 3/8 of sky covered) 

4 4 oktas (or 4/8 of sky covered) 

5 5 oktas (or 5/8 of sky covered) 

6 6 oktas (or 6/8 of sky covered) 

7 7 oktas or more but not 8 oktas 

8 8 oktas or sky completely covered 

9 Sky obscured (place holder)

TABLE 11 C 

0 Cirrus (Ci) 

1 Cirrocumulus (Cc) 

2 Cirrostratus (Cs) 

3 Altocumulus (Ac) 

4 Altostratus (As) 

5 Nimbostratus (Ns) 

6 Stratocumulus (Sc) 

7 Stratus (St) 

8 Cumulus (Cu) 

9 Cumulonimbus (Cb) 

/ Cloud type unknown due to darkness 

or other analogous phenomena 

TABLE 12 hshsHtHthihiHiHi 

00 Less than 100 

01 100 ft 

02 200 ft 

03 300 ft 

etc, etc 

49 4,900 ft 

50 5,000 ft 

51-55 Not used 

56 6,000 ft 

57 7,000 ft 

etc, etc 

79 29,000 ft 

80 30,000 ft 

81 35,000 ft 

82 40,000 ft 

etc, etc 

89 Greater than 70,000 ft 

// Unknown 

TABLE 13 dw 

0 No report 5 SW 

1 NE 6 W 

2 E 7 NW 

3 SE 8 N 

4 S 9 all directions 

TABLE 14 Ws 

0 No change 

1 Marked wind shift 

2 Beginning or ending or marked 

turbulence 

3 Marked temperature change (not with 

altitude) 

4 Precipitation begins or ends 

5 Change in cloud forms 

6 Fog or ice fog bank begins or ends 

7 Warm front 

8 Cold Front 

9 Front, type not specified 

TABLE 15 SbSeSs 

0 No report 

1 Previous position 

2 Present position 

3 30 nautical miles 

4 60 nautical miles 

5 90 nautical miles 

6 120 nautical miles 

7 150 nautical miles 

8 180 nautical miles 

9 More than 180 nautical miles 

/ Unknown (not used for Ss)
G-4 

Table G-1 (continued). Reconnaissance Code Tables

TABLE 16 wd 

0 No report 

1 Signs of a tropical cyclone 

2 Ugly threatening sky 

3 Duststorm or sandstorm 

4 Fog or ice fog 

5 Waterspout 

6 Cirrostratus shield or bank 

7 Altostratus or altocumulus shield or 

bank 

8 Line of heavy cumulus 

9 Cumulonimbus heads or 

thunderstorms 

TABLE 17 Ir 

7 Light 

8 Moderate 

9 Severe 

/ Unknown or contrails 

TABLE 18 It 

0 None 

1 Rime ice in clouds 

2 Clear ice in clouds 

3 Combination rime and clear ice in 

clouds 

4 Rime ice in precipitation 

5 Clear ice in precipitation 

6 Combination rime and clear ice in 

precip 

7 Frost (icing in clear air) 

8 Nonpersistent contrails (less than 

1/4 nautical miles long) 

9 Persistent contrails 

TABLE 19 Sr,Ew,El 

0 0NM 5 50NM 

1 10NM 6 60-80NM 

2 20NM 7 80-100NM 

3 30NM 8 100-150NM 

4 40NM 9 Greater than 150NM 

 / Unknown 

TABLE 20 Oe 

0 Circular 

1 NNE - SSW 

2 NE - SW 

3 ENE - WSW 

4 E - W 

5 ESE - WNW 

6 SE - NW 

7 SSE - NNW 

8 S - N 

/ Unknown 

TABLE 21 ce 

1 Scattered Area 

2 Solid Area 

3 Scattered Line 

4 Solid Line 

5 Scattered, all quadrants 

6 Solid, all quadrants 

/ Unknown 

TABLE 22 ie 

2 Weak 

5 Moderate 

8 Strong 

/ Unknown

TABLE 23 Vi 

1 Inflight visibility 0 to and including 1 nautical mile 

2 Inflight visibility greater than 1 and not exceeding 3 nautical miles 

3 Inflight visibility greater than 3 nautical miles 

RECCO SYMBOLIC FORM 

SECTION ONE (MANDATORY) 

9XXX9 GGggid YQLaLaLa LoLoLoBfc hahahadtda 

ddfff TTTdTdw /jHHH 

SECTION TWO (ADDITIONAL) 

1knNsNsNs ChshsHtHt ..... ..... 4ddff 

6WsSsWddw 7IrI

t

SbSe 7hihiHiHi 8drdrSrOe

8EwElcei

e 9Vi

TwTwTw

SECTION THREE (INTERMEDIATE) 

9XXX9 GGggid YQLaLaLa LoLoLoBfc hahahadtda

ddfff TTTdTdw /jHHH 
G-5 

Table G-2. Reconnaissance Code Regulations 

1. At the time of the observation the aircraft observing 

platform is considered to be located on the axis of a right 

vertical cylinder with a radius of 30 nautical miles 

bounded by the earth's surface and the top atmosphere. 

Present weather, cloud amount and type, turbulence, and 

other subjective elements are reported as occurring within 

the cylinder. Flight level winds, temperature, dew point, 

and geopotential values are sensed or computed and 

reported as occurring at the center of the observation 

circle. Radar echoes, significant weather changes, distant 

weather, and icing are phenomena that may also be 

observed/reported. Code groups identifying these 

phenomena may be reported as necessary to adequately 

describe met conditions observed. 

2. The intermediate observation (Section Three) is 

reported following Section One (or Section Two if 

appended to Section One) in the order that it was taken. 

3. Plain language remarks may be added as appropriate. 

These remarks follow the last encoded portion of the 

horizontal or vertical observation and will clearly convey 

the intended message. Vertical observations will not 

include meteorological remarks. These remarks must 

begin with a letter or word-e.g. "FL TEMP" vice "700 

MB FL TEMP." The last report plain language remarks 

are mandatory, i.e., “LAST REPORT. OBS 01 thru 08 to 

KNHC, OBS 09 and 10 to KBIX." 

4. The hundreds digit of longitude is omitted for 

longitudes from 100° to 180°. 

5. Describe conditions along the route of flight actually 

experienced at flight level by aircraft. 

6. TT, TdTd. When encoding negative temperatures, 50 

is added to the absolute value of the temperature with the 

hundreds figure, if any, being omitted. A temperature of -

52°C is encoded as 02, the distinction between -52°C and 

2°C being made from id. Missing or unknown 

temperatures are reported as //. When the dew point is 

colder than -49.4°C, Code TdTd as // and report the actual 

value as a plain language remark - e.g. "DEW POINT 

NEG 52°C". 

7. When two or more types of w co-exist, the type with 

the higher code figure will be reported. Code Figure 1, 2 

and 3 are reported based on the total cloud amount 

through a given altitude, above or below the aircraft, and 

when other figures are inappropriate. The summation 

principle applies only when two or more cloud types 

share a given altitude. 

8. When j is reported as a /, HHH is encoded as ///. 

9. If the number of cloud layers reported exceeds 3, kn in 

the first 1-group reports the total number of cloud layers. 

The second 1-group reports the additional number of 

layers being reported exclusive of those previously 

reported. In those cases where a cloud layer(s) is 

discernible, but a descriptive cloud picture of the 

observation circle is not possible, use appropriate remarks 

such as "Clouds Blo" or "As Blo" to indicate the presence 

of clouds. In such cases, coded entries are not made for 

group 9. The sequence in which cloud amounts are 

encoded depends upon type of cloud, cloud base, and 

vertical extent of the cloud. The cloud with the largest 

numerical value of cloud type code (C) is reported first, 

regardless of coverage, base, or vertical extent. Among 

clouds of the same cloud type code, sharing a common 

base, the cloud of greatest vertical extent is reported first. 

The summation principle is not used; each layer is treated 

as though no other clouds were present. The total amount 

of clouds through one altitude shared by several clouds 

will not exceed 8 oktas. Only use code figure 0 as a place 

holder when you can determine that no additional cloud 

layers exist. In case of undercast, overcast, etc., use code 

figure 9 as a placeholder. 

10. Due to limitations in the ability to distinguish sea 

state features representative of wind speeds above 130 

knots, surface wind speeds in excess of 130 knots will 

not be encoded. Wind speeds of 100 to 130 knots 

inclusive will be encoded by deleting the hundreds figure 

and adding 50 to dd. For wind speeds above 130 knots, 

dd is reported without adding 50 and ff is encoded as // 

with a plain language remark added, i.e., "SFC WIND 

ABOVE 130 KNOTS." 

11. Significant weather changes which have occurred 

since the last observation along the track are reported for 

Ws. 

12. When aircraft encounters icing in level flight, the 

height at which the icing occurred will be reported for hih

i

. The HiHi will be reported as //. 
G-6 

THE HDOB MESSAGE 

The HDOB message is used to transmit High-Density/High-Accuracy (HD/HA) meteorological 

data from hurricane reconnaissance aircraft. These are created automatically by the system 

software. Each message consists of a communications header line (Table G-3), a mission/ob 

identifier line (Table G-4), and 20 lines of HD/HA data (Table G-5). 

Within an HDOB message, the time interval (resolution) between individual HD/HA 

observations can be set by the operator to be 30, 60, or 120 seconds. However, regardless of the 

time resolution of the HD/HA data, the meteorological parameters in the HDOB message always 

represent 30-second averages along the flight track (except for certain peak values as noted in 

Table G-5). 

The nominal time of each HD/HA record is the midpoint of the 30-second averaging interval. 

This means that an HD/HA record at time t will include data measured at time t+15 seconds. For 

purposes of determining peak flight-level and SFMR winds, the encoding interval begins 15 

seconds after the nominal time of the last HD/HA record and ends 15 seconds after the nominal 

time of the record being encoded. 

A sample HDOB message is given below (message begins with URNT15...): 

0 1 2 3 4 5 6 7 

01234567890123456789012345678901234567890123456789012345678901234567890 

----------------------------------------------------------------------- 

URNT15 KNHC 281426 

AF302 1712A KATRINA HDOB 41 20050928 

142030 2608N 08756W 7093 03047 9333 +192 +134 133083 089 080 /// 00 

142100 2609N 08755W 7091 03054 9330 +166 +146 133106 115 103 /// 00 

142130 2610N 08754W 7058 03040 9295 +134 +134 135121 124 111 /// 00 

142200 2611N 08753W 7037 03060 9291 +124 +124 138129 136 122 /// 00 

. 

. 

. 

142230 2612N 08752W 7010 03057 9282 +102 +102 141153 166 148 /// 00 

142300 2612N 08751W 7042 03010 9293 +088 +083 133159 164 147 /// 00 

142330 2613N 08750W 6999 03064 9279 +088 +088 138158 161 144 /// 00 

142400 2614N 08749W 7005 03046 9281 +080 +080 138155 158 142 /// 00 

142430 2614N 08748W 6998 03048 9278 +078 +078 138151 153 137 /// 00 

142500 2615N 08747W 7002 03048 9279 +084 +084 140146 148 133 /// 00 

$$ 

Figure G-2. HDOB Description and Sample Message
G-7 

Table G-3. Communications Headers for HDOB Messages 

 NODE AWIPS ID WMO HEADER OCEAN BASIN 

 MIA AHONT1 URNT15 .... Atlantic 

 MIA AHOPN1 URPN15 .... East and Central Pacific 

 MIA AHOPA1 URPA15 .... West Pacific 

Table G-4. Mission/Ob Identifier Line Format for HDOB Messages 

A sample mission/ob identifier line is given below (beginning with AF302...), followed by a 

description of the parameters. 

0 1 2 3 4 5 6 7 

01234567890123456789012345678901234567890123456789012345678901234567890 

----------------------------------------------------------------------- 

IIIIIIIIIIIIIIIIIIIIIIIIIIIIII HDOB NN YYYYMMDD 

AF302 1712A KATRINA HDOB 41 20050928  example 

III...III: Mission identifier, as determined in Chapter 5, paragraph 5.7.6. 

NN: Observation number (01-99), assigned sequentially for each HDOB 

 message during the flight. This sequencing is independent of the 

 numbering of other types of messages (RECCO, DROP, VORTEX, etc.), 

 which have their own numbering sequence. 

YYYYMMDD: Year, month, and day of the first HD/HA data line of the message. 
G-8 

Table G-5. HD/HA Data Line Format for HDOB Messages 

0 1 2 3 4 5 6 7 

01234567890123456789012345678901234567890123456789012345678901234567890 

----------------------------------------------------------------------- 

hhmmss LLLLH NNNNNW PPPP GGGGG XXXX sTTT sddd wwwSSS MMM KKK ppp FF

142230 2612N 08752W 7010 03057 9282 +102 +102 141153 166 148 /// 00 

hhmmss: Observation time, in hours, minutes and seconds (UTC). The observation time is 

the midpoint of the 30-s averaging interval used for the record’s meteorological 

data. 

LLLLH: The latitude of the aircraft at the observation time in degrees (LL) and minutes 

(LL). The hemisphere (H) is given as either N or S. 

NNNNNH: The longitude of the aircraft at the observation time, in degrees (NNN) and 

minutes (NN). The hemisphere (H) is given as either E or W. 

PPPP: Aircraft static air pressure, in tenths of mb with decimal omitted, at the 

observation time. If pressure is equal to or greater than 1000 mb the leading 1 is 

dropped. 

GGGGG: Aircraft geopotential height, in meters, at the observation time. 

XXXX: Extrapolated surface pressure or D-value (30-s average). Encoded as extrapolated 

surface pressure if aircraft static pressure is 550.0 mb or greater (i.e., flight 

altitudes at or below 550 mb). Format for extrapolated surface pressure is the 

same as for static pressure. For flight altitudes higher than 550 mb, XXXX is 

encoded as the D-value, in meters. Negative D-values are encoded by adding 

5000 to the D-value. /// indicates missing value. 

s: Sign of the temperature or dew point (+ or -). 

sTTT: The air temperature in degrees and tenths Celsius, decimal omitted (30-s average). 

/// indicates missing value.

sddd: The dew point temperature, in degrees and tenths Celsius, decimal omitted (30-s 

average). /// indicates missing value.

www: Wind direction in degrees (30-s average). North winds are coded as 000. /// 

indicates missing value. 

SSS: Wind speed, in kt (30-s average). /// indicates missing value. 

MMM: Peak 10-second average wind speed occurring within the encoding interval, in kt. 
G-9 

/// indicates missing value. 

KKK: Peak 10-second average surface wind speed occurring within the encoding 

interval from the Stepped Frequency Microwave Radiometer (SFMR), in kt. /// 

indicates missing value. 

ppp: SFMR-derived rain rate, in mm hr-1, evaluated over the 10-s interval chosen for 

KKK . /// indicates missing value. 

FF: Quality control flags. 

First column indicates status of positional variables as follows: 

0 All parameters of nominal accuracy 

 1 Lat/lon questionable 

 2 Geopotential altitude or static pressure questionable 

 3 Both lat/lon and GA/PS questionable 

 Second column indicates status of meteorological variables as follows: 

0 All parameters of nominal accuracy 

1 T or TD questionable 

2 Flight-level winds questionable 

3 SFMR parameter(s) questionable 

4 T/TD and FL winds questionable 

5 T/TD and SFMR questionable 

6 FL winds and SFMR questionable 

9 T/TD, FL winds, and SFMR questionable 
G-10 

Table G-6. TEMP DROP CODE

EXTRACT FROM: WMO-No. 306 MANUAL ON CODES 

FM 37-X Ext. TEMP DROP: Upper-level pressure, temperature, humidity and wind report from a sonde released by 

carrier balloons or aircraft. See Figure G-3 for an example TEMP DROP message for tropical cyclone operations. 

CODE FORM:

PART A

SECTION 1 MiMiMjMj YYGGId 99LaLaLa QcLoLoLoLo MMMULaULo

SECTION 2 99PoPoPo ToToTaoDoDo dodofofofo

 P1P1h1h1h1 T1T1Ta1D1D1 d1d1f1f1f1

 PnPnhnhnhn TnTnTanDnDn dndnfnfnfn

SECTION 3 88PtPtPt TtTtTatDtDt dtdtftftft

 or 

 88999 

SECTION 4 77PmPmPm dmdmfmfmfm (4vbvbvava) 

 or 

 66PmPmPm dmdmfmfmfm (4vbvbvava) 

 or 

 77999 

 

SECTION 10 31313 

 

 51515 101Adf Adf 0PnPnP'nP'n. 

 or 

 101Adf Adf PnPnhnhnhn 

 61616 

 

 62626 

PART B

SECTION 1 MiMiMjMj YYGG8 99LaLaLa QcLoLoLo MMMULaULo

SECTION 5 nonoPoPoPo ToToTaoDoDo

n1n1P1P1P1 T1T1Ta1D1D1

nnnnPnPnPn TnTnTanDnDn

SECTION 6 21212 nonoPoPoPo dodofofofo
G-11 

n1n1P1P1P1 d1d1f1f1f1

nnnnPnPnPn dndnfnfnfn

SECTION 7 31313 srrarasasa 8GGgg 

SECTION 9 51515 101Adf Adf or 

 101Adf Adf 0PnPnP'nP'n. or 

 101Adf Adf PnPnhnhnhn 

SECTION 10 61616 

 62626 

PART ALPHA (A)

IDENTIFICATION LETTERS: MJMJ

Identifier: MJMJ - Identifier for Part A of the report. 

DATE/TIME GROUP: YYGGId

Identifier: YY - Date group 

Identifier: GG - Time group 

Identifier: Id - The highest mandatory level for which wind is available. 

LATTITUDE: 99LaLaLa 

Identifier: 99 – Indicator for data on position follows. 

Identifier: LaLaLa – Latitude in tenths of degrees 

LONGITUDE: QcLoLoLoLo 

Identifier: Qc – The octant of the globe. 

Identifier: LoLoLoLo – Longitude in tenths of degrees

MARSDEN SQUARE: MMMUlaUlo

Identifier: MMM - Marsden square. 

Identifier: UlaUlo – Units digits in the reported latitude and longitude. 

SEA LEVEL PRESSURE: 99P0P0P0 T0T0T0D0D0 d0d0f0f0f0 

Identifier: 99 – Indicator for data at the surface level follows 

Identifier: P0P0P0 – Indicator for pressure of specified levels in whole millibars (thousands digit omitted) 

Identifier: T0T0T0– Tens and digits of air temperature (not rounded off) in degrees Celsius, at specified levels 

beginning with surface. 

Identifier: D0D0 – Dewpoint depression at standard isobaric surfaces beginning with surface level. 

NOTE

When the depression is 4.9C or less encode the units and tenths digits of the depression. Encode 

depressions of 5.0 through 5.4C as 50. Encode depressions of 5.5C through 5.9C as 56. Dew point 
G-12 

depressions of 6.0 and above are encoded in tens and units with 50 added. Dew point depressions 

for relative humidities less then 20% are encoded as 80. When air temperature is below –40C 

report DnDn as //. 

Identifier: dodo – True direction from which wind is blowing rounded to nearest 5 degrees. Report hundreds and tens 

digits. The unit digit (0 or 5) is added to the hundreds digit of wind speed. 

Identifier: fofofo – Wind speed in knots. Hundreds digit is sum of speed and unit digit of direction, i.e. 295o at 125 

knots encoded as 29625. 

NOTE: 1. When flight level is just above a standard surface and in the operator’s best meteorological judgment, the 

winds are representative of the winds at the standard surface, then the operator may encode the standard surface 

winds using the data from flight level. If the winds are not representative, then encode /////. 

NOTE: 2. The wind group relating to the surface level (dodofofofo) will be included in the report; when the 

corresponding wind data are not available, the group will be encoded as /////. 

STANDARD ISOBARIC SURFACES : P1P1h1h1h1 T1T1T1D1D1 d1d1f1f1f1

Identifier: P1P1 – Pressure of standard isobaric surfaces in units of tens of millibars. 

 (1000 mbs = 00, 925mbs = 92, 850mbs = 85, 700mbs = 70, 500mbs = 50, 400mbs = 40, 300mbs = 30, 

 250mbs = 25). 

Identifier: h1h1h1 – Heights of the standard pressure level in geopotential meters or decameters above the 

surface. Encoded in decameters at and above 500mbs omitting, if necessary, the thousands or tens of 

thousands digits. Add 500 to hhh for negative 1000mb or 925mb heights. Report 1000mb group as 00/// 

///// ///// when pressure is less than 950mbs. 

Identifier: T1T1T1D1D1 – Same temperature/dew point encoding procedures apply to all levels. 

Identifier : d1d1f1f1f1 – Same wind encoding procedures apply to all levels. 

DATA FOR TROPOPAUSE LEVELS: 88 PtPtPt TtTtTtDtDt dtdtftftft

Identifier: 88 – Indicator for Tropopause level follows 

Identifier: PtPtPt– Pressure at the tropopause level reported in whole millibars. Report 88PnPnPn as 88999 when 

tropopause is not observed. 

Identifier: TtTtTtDtDt – Same temperature/ dew point encoding procedures apply. 

Identifier: dtdtftftft - Same wind encoding procedures apply. 

MAXIMUM WIND DATA: 77PnPnPn dndnfnfnfn 4vbvbvava

Identifier: 77 – Indicator that data for maximum wind level and for vertical wind shear follow when max wind does 

not coincide at flight. If the maximum wind level coincides with flight level encode as 66 

Identifier: PnPnPn.– Pressure at maximum wind level in whole millibars. 

Identifier: dndnfnfnfn - Same wind encoding procedures apply. 

VERTICAL WIND SHEAR DATA: 4vbvbvava 

Identifier: 4 – Data for vertical wind shear follow. 

Identifier: vbvb – Absolute value of vector difference between max wind and wind 3000 feet BELOW the level of 

max wind, reported to the nearest knot. Use “//” if missing and a 4 is reported. A vector difference of 99 knots 

or more is reported with the code figure “99”. 
G-13 

Identifier: vava – Absolute value of vector difference between max wind and wind 3000 feet above the level of max 

wind, reported to the nearest knot. Use “//” if missing and a 4 is reported. A vector difference of 99 knots or 

more is reported with the code figure “99”. 

 

 SOUNDING SYSTEM INDICATION, RADIOSONDE/ SYSTEM STATUS, LAUNCH TIME:

 31313 srrarasasa 8GGgg 

Identifier: srrarasasa - Sounding system indicator, radiosonde/ system status: sararasasa

Identifier: sa - Solar and infrared radiation correction ( 0 – no correction) 

Identifier: rara – Radiosonde/sounding system used ( 96 – Descending radiosonde) 

Identifier: sasa – Tracking technique/status of system used ( 08 – Automatic satellite navigation) 

Identifier: 8GGgg – Launch time 

Identifier: 8 – Indicator group 

Identifier: GG – Time in hours 

Identifier: gg – Time in minutes 

ADDITIONAL DATA GROUPS: 51515 101XX 0PnPnPnPn

Identifier: 51515 – Additional data in regional code follow 

Identifier: 10166 – Geopotential data are doubtful between the following levels 0PnPnPnPn. This code figure is used 

only when geopotential data are doubtful from one level to another. 

Identifier: 10167 – Temperature data are doubtful between the following levels 0PnPnPnPn. This code figure shall be 

reported when only the temperature data are doubtful for a portion of the descent. If a 10167 group is reported a 

10166 will also be reported. EXAMPLE: Temperature is doubtful from 540mbs to 510mbs. SLP is 1020mbs. 

The additional data groups would be : 51515 10166 00251 10167 05451. 

Identifier: 10190 – Extrapolated altitude data follows: 

When the sounding begins within 25mbs below a standard surface, the height of the surface is reported 

in the format 10190 PnPnhnhnhn. The temperature group is not reported. EXAMPLE: Assume the 

release was made from 310mbs and the 300mb height was 966 decameters. The last reported 

standard level in Part A is the 400mb level. The data for the 300mb level is reported in Part A and B 

as 1019030966. 

When the sounding does not reach surface, but terminates within 25mbs of a standard surface, the height 

of the standard surface is reported in Part A of the code in standard format and also at the end of Part 

A and Part B of the code in the format as 10190 PnPnhnhnhn. 

EXAMPLE: Assume termination occurred at 980mbs and the extrapolated height of the 1000mb 

level was 115 meters. The 1000mb level would be reported in Part A of the code as 00115 ///// ///// 

and in Part B as 10190 00115. 

Identifier: 10191 – Extrapolated surface pressure precedes. Extrapolated surface pressure is only reported when the 

termination occurs between 850mbs and the surface. Surface pressure is reported in Part A as 99P0P0P0 ///// and in 

Part B as 00P0P0P0 /////. When surface pressure is extrapolated the 10191 group is the last additional data group 

reported in Part B. 

AIRCRAFT AND MISSION IDENTIFICATION: 61616 AFXXX XXXXX XXXXX OB X 

Identifier: 61616 – Aircraft and mission identification data follows. 

Identifier: AFXXX – The identifier AF for U.S. Air Force and the last three digits of the aircraft’s tail number. 

Identifier: XXXXX XXXXX – The identifier for the type of mission being flown.

If a training mission the mission identifier is WXWXA TRAIN. The fifth letter “A” is the only 

character that could possibly change. The “A” indicates that the flight originated in the Atlantic 

basin. The letter “C” identifies the Central Pacific area, and the letter “E” identifies the Eastern 

Pacific. 

If an operational storm mission: the first two numbers Identifier the number of times an aircraft has 

flown this system and the second two numbers Identifier the system number. The last character 
G-14 

again identifies the basin flown. The name of the storm would replace TRAIN. 

EXAMPLE: AF968 0204A MARIE – Aircraft number 50968, this was the second flight into this 

system and the system was the fourth of the season. The system reached tropical storm strength and 

was named MARIE. 

Identifier: OB 14 – The observation (both vertical and horizontal) number as transmitted from the aircraft. 

NATIONALLY DEVELOPED CODES: 62626

Identifier: 62626 – This is the remarks section. Only the remarks EYE, EYEWALL XXX, MXWNDBND, or 

RAINBAND will be used. If the remark EYEWALL is used it will be followed by the octant (degrees) sonde is 

located relative to eye center. Example: If the sonde is released in the NE quad of the storm, XXX is 045. 

Identifier: REL XXXXNXXXXXW hhmmss – Release location of the sonde and the release time. 

Identifier: REL XXXXNXXXXXW hhmmss - the time and location of the highest (in altitude) wind reported in 

the tempdrop message

Identifier: SPG XXXXNXXXXXW hhmmss - Impact location of the sonde based on its last GPS position and the 

splash time. 

Identifier: SPG XXXXNXXXXXW hhmmss - the time and location of the lowest (in altitude) wind reported in the 

tempdrop message. 

Identifier: SPL XXXXNXXXXXW hhmm - Impact location of the sonde based on its last GPS position and the 

splash time. (SPL has less precision than SPG and may be removed in the next version of the NHOP). 

Identifier: LAST WND XXX - Height of the last reported wind. If a surface wind is reported the Last Wind remark 

is omitted. XXX will never be less than 13 meters 

Identifier: MBL WND dddff - The mean boundary level wind. The mean wind in the lowest 500 meters of the 

sounding 

Identifier: AEV XXXXX - This is the software version being used for the sounding. 

Identifier: DLM WND ddfff bbbttt - The Deep Layer Mean wind. It is the average wind over the depth of the 

sounding. Where ddfff is the wind averaged from the first to the last available wind (these would correspond to 

the first and last significant levels for wind); ttt is the pressure at the top of the layer, and bbb is the pressure at 

the bottom of the layer (in whole mbs, with thousands digit omitted). 

Identifier: WL150 ddfff zzz - Average wind over the lowest available 150 m of the wind sounding. Where ddfff is 

the mean wind over the 150 m layer centered at zzz m. 

PART ALPHA (B)

DATA FOR SIGNIFICANT TEMPERATURE AND RELATIVE HUMIDITY LEVELSSIGNIFICANT 

ISOBARIC LEVELS: 

 n0n0P0P0P0 T0T0T0D0D0

IDENTIFICATION LETTERS: MJMJ

Identifier: MJMJ - Identifier for Part B of the report. 

DATE/TIME GROUP: YYGG8 

Identifier: YY - Date group 

Identifier: GG - Time group 

Identifier: 8 - Indicator for the use of satellite navigation for windfinding. 

 

LATTITUDE: 99LaLaLa (Same as Part A) 

LONGITUDE: QcLoLoLoLo (Same as Part A) 

MARSDEN SQUARE: MMMUlaUlo (Same as Part A) 

SEA LEVEL PRESSURE: nonoP0P0P0 T0T0T0D0D0 

Identifier: nono – Indicator for number of level starting with surface level. Only surface will be numbered as “00”.
G-15 

Identifier: P0P0P0 – Indicator for pressure of specified levels in whole millibars (thousands digit omitted) 

Identifier: T0T0T0– Tens and digits of air temperature (not rounded off) in degrees Celsius, at specified levels 

beginning with surface. 

Identifier: D0D0 – Dewpoint depression at standard isobaric surfaces beginning with surface level. Encoded the 

same as Part A. 

FOR STORM DROPS ONLY. If SLP is less than 950mb encode the 1000mb group as 00/// ///// /////. When the 

SLP is between 950mb and 999mb encode 1000mb as 00PoPoPo ///// ///// (500 meters are added to height 

below surface). 

DATA FOR SIGNIFICANT WIND LEVELS: n0n0P0P0P0 dodofofofo

Identifier: n0n0 – Number of level starting with surface level. Only surface will be numbered as “00”. 

Identifier: P0P0P0 – Pressure at specified levels in whole millibars. 

Identifier: dodo – True direction from which wind is blowing rounded to nearest 5 degrees. Report hundreds and tens 

digits. The unit digit (0 or 5) is added to the hundreds digit of wind speed. 

Identifier: fofofo – Wind speed in knots. Hundreds digit is sum of speed and unit digit of direction, i.e. 295o at 125 

knots encoded as 29625. 

Same notes in Part A apply. 

31313, 51515, 61616, 62626 – Repeated from Part A. 

FIGURE G-3. EXAMPLE TEMP DROP MESSAGE FOR TROPICAL CYCLONES

UZNT13 KNHC 080839 

XXAA 58088 99192 70803 04590 99964 21676 20581 00814 ///// ///// 

92359 20476 22611 85085 18876 24614 88999 77999 

31313 09608 80747 

51515 10190 70752 

61616 AF302 0617A PALOMA OB 16 

62626 EYEWALL 225 SPL 1925N08021W 0750 MBL WND 22112 AEV 20800 DL 

M WND 23107 964833 WL150 21611 079 REL 1920N08030W 074700 SPG 192 

6N08021W 075012 = 

XXBB 58088 99192 70803 04590 00964 21676 11850 18876 22811 18476 

33760 19677 44739 21077 55719 23261 66701 11430 

21212 00964 20581 11963 20585 22960 20604 33958 21120 44955 21626 

55949 22107 66939 22621 77933 22614 88917 22611 99900 23099 11874 

23604 22867 24098 33864 24100 44859 24117 55850 24614 66701 26123 

31313 09608 80747 

51515 10190 70752 

61616 AF302 0617A PALOMA OB 16 

62626 EYEWALL 225 SPL 1925N08021W 0750 MBL WND 22112 AEV 20800 DL 

M WND 23107 964833 WL150 21611 079 REL 1920N08030W 074700 SPG 192 

6N08021W 075012 = 

H-1 

APPENDIX H

WSR-88D OPERATIONS PLAN FOR TROPICAL CYCLONE EVENTS 

 To perform radar center-fixing and obtain other diagnostic information, NHC must obtain 

radar products from WSR-88D sites in the area of landfall. As a tropical cyclone approaches, 

software commands must be issued at the site, using the Unit Control Position (UCP), in order 

for NHC to obtain the necessary products. To facilitate this process, NHC, in cooperation with 

the NWS Weather Forecast Office, Melbourne, and the NEXRAD Radar Operations Center 

(ROC), has developed an operations plan for use during tropical cyclone events. 

 The latest addition can be found on the OFCM web site at: 

http://www.ofcm.gov/homepage/text/pubs.htm 

I-1 

APPENDIX I 

TELEPHONE LISTING 

AGENCY LOCATION TELEPHONE

Department of Commerce 

NHC 

 Director 

 Atlantic Forecast Operations 

 Pacific Forecast Operations 

 Admin 

 Admin Fax 

 TAFB Lead Forecaster 

Miami, FL 

COM 305-229-4402 

COM 305-229-4415 

COM 305-229-4417 

COM 305-229-4470 

FAX 305-553-1901 

COM 305-229-4425 

CPHC 

 Director 

 Forecaster and Warning Desk 

 Admin 

 Operations 

 Satellite Coordinator 

Honolulu, HI 

COM 808-973-5272 

COM 808-973-5284 

COM 808-973-5270 

FAX 808-973-5281 

COM 808-973-5285 

NOAA Aircraft Operations Center MacDill AFB, FL COM 813-828-3310 

NCEP/NCO Senior Duty Met (Data QC) Camp Springs, MD COM 301-763-8298 

Hydrometeorological Prediction Center 

(NCEP/HPC) Camp Springs, MD COM 301-763-8201 

NESDIS Satellite Analysis Branch Camp Springs, MD COM 301-763-8444 

WFO Guam Tiyan, Guam COM 671-472-0950/1/2 

NDBC - Operations Branch Stennis Space Center, MS COM 228-688-7720 

NWS Hydrometeorological Services Core 

(Headquarters) Silver Spring, MD COM 301-713-1858, ext. 108 

FAX 301-713-1520 

Interdepartmental 

OFCM Silver Spring, MD COM 301-427-2002 

DSN 851-1460 

Department of Defense 

JTWC (Typhoon Duty Officer) Pearl Harbor, HI COM 808-474-2320 

53rd Weather Reconnaissance Squadron (WRS) 

 Supervisor of Flights 

 Chief ARWO 

 

 Alternate CARCAH 

53 WRS 

817 H Street, Suite 201 

Keesler AFB, MS 39534-2453 

DSN 597-2409 

COM 228-377-2409 

DSN 597-3207 

COM 228-377-3207 

DSN 597-9060 

COM 228-377-9060 

CARCAH OLA, 53d WRS Miami, FL COM 305-229-4474 

DSN 434-3420 

Keesler AFB Command Post Keesler AFB, MS COM 228-377-4181/4330 

DSN 597-4181/4330 

AFWA Offutt AFB, NE COM 402-294-2586 

DSN 271-2586 

FACSFAC VACAPES OAC Oceana, VA COM 804-433-1233 

DSN 433-1233 

FACSFAC Roosevelt Roads Roosevelt Roads, PR COM 787-865-7007 

DSN 831-7007/5202/5203 

17 OWS/WXJ (Satellite Analyst) Pearl Harbor, HI COM 787-865-7007 

DSN 471-3533 

601 AOC/CODW Tyndall AFB, FL COM 850-283-5119 

DSN 523-5119 

Fleet Weather Center Norfolk, VA COM 757-444-7583/7750 

DSN 564-7583/7750 

Fleet Numerical Meteorology & Oceanography 

Center (FNMOC) (Alternate JTWC) Monterey, CA COM 831-656-4325 

DSN 878-4325 
I-2 

TMC – Traffic Management Coordinator 

OMIC - Operations Manager in Charge 

STMC – Supervisor Traffic Management Coordinator 

Department of Transportation/Federal Aviation Administration 

Air Route Traffic Control Center (ARTCC) 

ARTCC Facility 

ID 

Primary 

Operations 

Contact Point 

Secondary 

Operations 

Contact Point 

(24 hour number) 

Operations 

Fax Number 

Center 

Weather 

Service Unit 

(CWSU) 

ANCHORAGE ZAN 907-269-1103 

(OMIC) 

907-269-1108 

(TMC) 907-269-1343 907-269-1145 

BOSTON ZBW 603-879-6663 

(TMC) 

603-879-6655 

(OMIC) 603-879-6461 603-879-6698 

HOUSTON ZHU 281-230-5563 

(Missions) 

281-230-5560 

(OMIC) 281-230-5561 281-230-5676 

JACKSONVILLE ZJX 904-549-1542 

(Missions) 

904-549-1537 

(OMIC) 904-549-1843 

904-549-1840 

or 904-549-

1839 

LOS ANGELES ZLA 661-265-8287 

(Missions) 

661-265-8205 

(OMIC) 661-265-8277 661-265-8258 

MIAMI ZMA 305-716-1589 

(Missions) 

305-716-1588 

(OMIC) 

305-716-1511 

or 305-716-

1577 

305-716-1635 

NEW YORK ZNY 631-468-1427 

(Missions) 

631-468-1080 

(STMC) 631-468-4224 631-468-1082 

OAKLAND ZOA 510-745-3332 

(Missions) 

510-745-3331 

(OMIC) 510-745-3339 510-745-3425 

SEATTLE ZSE 253-351-3523 

(Missions) 

253-351-3520 

(OMIC) 

253-351-3594 

or 253-351-

3538 

253-351-3741 

WASHINGTON ZDC 703-771-3473 

(Missions) 

703-771-3470 

(OMIC) 703-771-3444 703-771-3480 

HONOLULU 

HCF ZHN 808-840-6204 

(TMC) 

808-840-6201 

(Front Line Manager) 808-840-6210 N/A 

SAN JUAN 

CERAP ZSU 

787-253-8665 

(Front Line 

Manager) 

787-253-8664 

(Front Line Manager) 787-253-8650 N/A 

GUAM CERAP ZUA 

671-473-1210 

(Front Line 

Manager) 

671-473-1270 

(Missions) 671-473-1217 N/A 

Air Traffic Control System Command Center (ATCSCC) 

MANAGER, ATCSCC COM 540-422-4004 

PRIMARY OPERATIONS CONTACT POINT 

INTERNATIONAL OPERATIONS POSITION 

COM 540-422-4158 

FAX 540-422-4196 

SECONDARY OPERATIONS CONTACT POINT 

NATIONAL OPERATIONS MANAGER (NOM) 

COM 540-422-4100/4101/4102 

 800-333-4286 (Military Use Only) 

FAX 540-422-4196 

CENTRAL ALTITUDE RESERVATION 

FUNCTION (CARF) 

COM 540-422-4211/4212 

FAX 540-422-4291 

US NOTAM Office COM 540-422-4260/4261 

FAX 540-422-4983 
I-3 

Transport Canada (ANS Regulatory Authority) 

Civil Aviation Contingency Operations (CACO) 

Office 

COM (Toll-free from Canada) 1-877-992-6853 

FAX (Toll-free from Canada) 1-866-993-7768 

NAV CANADA (ANS Provider) 

National Operations Centre (NOC) 

Admin Hours 0600-2200 (local Eastern time) 

NOC (24 Hours) (ATCSCC of Canada) 

COM 613-563-5626 

COM 613-563-5667 

COM (Toll-free from Canada) 1-866-561-9053 

COM (Toll-free from U.S.A.) 1-866-651-9056 

FAX 613-563-3481 

International NOTAM Office (Canada) COM 613-248-4000 

FAX 613-248-4001 

Altitude Reservation Units (ARU) 

ARU West (Edmonton ACC) (responsible for 

Vancouver, Edmonton and Winnipeg FIRs) 

COM 780-890-4739 

FAX 780-890-4738 

ARU East (Gander ACC) (responsible for Toronto, 

Montreal, Moncton and Gander FIRs) 

COM 709-651-5243 

FAX 709-651-5288

Area Control Centers (ACC) 

ACC Facility ID 

Primary 

Operations 

Contact Point 

(Shift Manager) 

Secondary 

Operations 

Contact Point 

Fax Number 

TORONTO ZYZ 905-676-4509 905-676-4562 905-612-5613 

MONTREAL ZUL 514-633-3365 514-633-2871 514-633-3371 

MONCTON ZOM 506-867-7173 506-381-4684 506-867-7180 

WINNIPEG ZWG 204-983-8338 204-983-8483 204-984-0030 

EDMONTON ZEG 780-890-8397 780-890-8323 780-890-8011 

GANDER ZQX 709-651-5207 709-651-5223 709-651-5234 

VANCOUVER ZVR 604-598-4500 604-598-4850 604-586-4502 

J-1 

APPENDIX J

GEOGRAPHICAL DEFINING POINTS AND PHONETIC PRONUNCIATIONS 

Abaco AB-a-KO 

Abreojos aahbray-oh-hoes 

Amalie a-MAHL-ye 

Angel aan-hel 

Anguilla ang-GWIL-a 

Antigua an-TEE-ga 

Arena aah-ray-nah 

Arista ah-ree-staa 

Aruba ah-ROO-ba 

Antilles an-TILL-leez 

Azores uh-ZOHRZ 

Bahia ba-e-yuh 

Ballenas ba-yaynas 

Barahona ba-ra-HO-na 

Barbados bar-BAY-dohz 

Barbuda bar-BOO-dah 

Barra baa-rra 

Barranquilla Bahr-rahn-KEE-yah 

Basse-Terre baha-TER 

Bimini BIM-I-ni 

Bonaire ba-NAIR 

Burros bhoorroes 

Cap Haitien kahp ah-ee-SYAN 

Caracas kah-RAH-kahs 

Cardenas car-denaass 

Caribbean kar-a-BE-an 

Castries KAS-tree 

Cayman kay-MAHN 

Champerico chaam-per-e-coe 

Charlotte 

Colima coleema 

Corrientes cor-re-ehn-tays 

Cozumel koh-soo-MEL 

Curacao koor-a-SOH 

Cuyutlan coo-yootlaan 

Dominica dom-I-NEE-ka 

Eleuthera el-OO-thera 

Escondido es-cond-dee-dow 

Eugenia ayuh-hen-yuh 

Exuma ek-SOO-ma 

Flores FLO-rish 

Fort de France for-de-FRAHCS 

Galera gaa-lehra 

Grenada gre-NAY-dah 

Guadaloupe GWAH-deh-loop 

Guasave gwaa-saa-ve 

Guaymas gwhy-maahs 

Huatulco whaa-tool-coe 

Islas eeslas 

Jalisco ha-lee-sco 

Juanico whaa-nee-coe 

Lazaro laasa-roe 

Loreto lo-ae-toe 

Leeward LEE-werd 

Manzanillo manza-nee-oh 

Maracaibo mar-a-KYE-boh 

Maracay mah-rah-KYE 

Marigot ma-ree-GOH 

Mateo muh-ta-yo 

Mayaguez may-yah-GWAYS 

Medano may-daa-no 

Melaque may-laa-kay 

Merida MAY-re-thah 

Mochis mo-chees 

Montego mon-TEE-go 

Montserrat mont-se-RAT 

Mugu muhgu 

Mulege moo-lay-hay 

Nicaragua nik-a-RAH-gwah 
J-2 

Ocho Rios OH-cho REE-os 

Oranjestad o-RAHN-yuh-stat 

Paramaribo par-a-MAR-I-boh 

Parguera par-GWER-a 

Penasco pen-yaas-co 

Pointe-a-Pitre pwan-ta-PEE-tr 

Ponce PON-sa 

Port-au-Prince port-oh-PRINS 

Punta poonta 

Revillagigedo ray-veeaheehaydo 

Saba SAH-ba 

Sao Miguel soun ME-gel 

Sipacate see-paa-caa-tay 

St Croix ST croy 

St Lucia ST LOO-she-a 

Soufriere soo-free-AR 

Surinam SOOR-I-nam 

Tampico tam-PEE-ko 

Tehuantepec te-whaan-te-pec 

Tela TAY-lah 

Tobago to-BAY-go 

Todos todohs 

Tomas tow-maas 

Tonala ton-aahla 

Tosca toesca 

Vallarta vah-yar-ta 

Yavaros yaa-vaa-roce 

Yucatan yoo-ka-TAN 

Zihuatanejo zeeh-whaa-tanayho 
K-1 

APPENDIX K

NHOP OPERATIONAL MAPS 

(TERMINAL AREAS)

Figure K-1. Texas Coast 
K-2 

Figure K-2. Lake Charles, LA - Pensacola, FL
K-3 

Figure K-3. Pensacola, FL – Tallahassee, FL
K-4 

Figure K-4. Central/Southern Florida
K-5 

Figure K-5. Cuba – Grand Cayman 
K-6 

Figure K-6. The Bahamas: Nassau - Freeport 
K-7 

Figure K-7. Turks & Caicos Islands: Grand Turk - Providenciales 
K-8 

Figure K-8. Daytona Beach, FL – Myrtle Beach, SC
K-9 

Figure K-9. Wilmington, DE – Atlantic City, NJ
K-10 
L-1 

APPENDIX L

MISSION COORDINATION SHEET 

1. Aircraft Call Sign: 

2. TCPOD Number: 

3. Departure & Planned Recovery Airfields: 

4. Route of Flight: 

 

5. Storm Center Coordinates: 

6. Radius of Operation from Center Coordinates: 

Note: This area excludes the terminal areas (Class D Airspace) and any other airspace within 50 NM of the 

CONUS shoreline until radio contact is established with ATC. 

7. Expected Entry & Exit Times for Operating Area: 

8. Requested Operating Area Altitude/Block: 

9. Aircraft SATCOM #: 

10. HF SELCAL (if applicable): 

11. NORAD Transponder Code: 

12. POC Contact Information: 

M-1 

APPENDIX M 

ACRONYMS/ABBREVIATIONS 

-AAB Data type header for Tropical Weather Outlook 

AFB Air Force Base 

AFRC Air Force Reserve Command 

AFSATCOM Air Force Satellite Communications System 

AFWA Air Force Weather Agency 

AGL Above Ground Level 

AMSU Advanced Microwave Sounding Unit 

AOC Aircraft Operations Center (NOAA) 

APT Automatic Picture Transmission 

ARGOS Argos, Inc., a French data collection system 

ARINC Aeronautical Radio, Incorporated 

ARSA Airport Radar Service Area 

ARTCC Air Route Traffic Control Center 

ARWO Aerial Reconnaissance Weather Officer 

ASDL Aircraft-to-Satellite Data Link 

ATC Air Traffic Control 

ATCSCC Air Traffic Control System Command Center 

AVAPS Advanced Vertical Atmospheric Profiling System 

AVHRR Advanced Very High Resolution Radiometer 

AWIPS Advanced Weather Interactive Processing System 

-CCARCAH Chief, Aerial Reconnaissance Coordination, All Hurricanes 

CARF Central Altitude Reservation Function 

CERAP Combined Center RAPCON (FAA) 

CFW Coastal/Lakeshore Hazard Message products (AWIPS Product 

 Category CFW) 

C.I. Current Intensity 

C-MAN Coastal-Marine Automated Network 

CNMI Commonwealth of the Northern Mariana Islands 

COM Commercial (telephone) 

CONUS Continental United States 

CPHC Central Pacific Hurricane Center 
M-2 

-DDA Daylight Ascending 

deg degree (latitude or longitude) 

DMSP Defense Meteorological Satellite Program 

DOC Department of Commerce 

DOD Department of Defense 

DOT Department of Transportation 

DPTD departed 

DROP dropsonde/dropwindsonde 

DSN Defense Switched Network (formerly AUTOVON) 

-EESA European Space Agency 

ESPC Environmental Satellite Processing Center 

ETA Estimated Time of Arrival 

-FFAA Federal Aviation Administration 

FACSFAC Fleet Aerial Control and Surveillance Facility 

FCMSSR Federal Committee for Meteorological Services and Supporting 

 Research 

FCST forecast 

FCSTR forecaster 

FEA Flow Evaluation Area (FAA) 

FL flight level 

FLT LVL flight level 

FMH Federal Meteorological Handbook 

FNMOC Fleet Numerical Meteorology and Oceanography Center (USN) 

FSM Federated States of Micronesia 

ft foot/feet 

-GGAC Global Area Coverage 

GOES Geostationary Operational Environmental Satellite 

GMDSS Global Maritime Distress and Safety System 
M-3 

-HHA High Accuracy 

HD High Density 

HDOB High Density Observation 

HF High Frequency 

hPa hectopascal/hectopascals 

h hour/hours 

HLS Hurricane Local Statement 

HNL Honolulu (CPHC) 

HPC Hydrometeorological Prediction Center (NCEP) 

HRD Hurricane Research Division (NOAA/OAR/AOML) 

HRPT High Resolution Picture Transmission 

-IICAO International Civil Aviation Organization 

ICMSSR Interdepartmental Committee for Meteorological Services and 

Supporting Research 

ID identification 

IFR Instrument Flight Rules 

IOM International Operations Manager (FAA) 

IR Infrared 

-JJTWC Joint Typhoon Warning Center 

-Kkm kilometer/kilometers 

KBIX ICAO identifier for Keesler AFB, MS 

KNHC ICAO identifier for the National Hurricane Center, Miami, FL 

kt knot/knots 

-LLAC Local Area Coverage 

LI Long Island 
M-4 

-Mm meter/meters 

MAX maximum 

METEOSAT European Space Agency geostationary meteorological satellite 

MIA Minimum IFR Altitude 

min/MIN minute 

MHS Microwave Humidity Sounder 

mph mile/miles per hour 

MSL Mean Sea Level 

MTSAT-1R Japanese Geostationary Satellite 

MVMT movement 

-NNASA National Aeronautics and Space Administration 

NAVLANTMETOCFAC Naval Atlantic Meteorology and Oceanography Facility 

NAVMETOCCOM Naval Meteorology and Oceanography Command 

NAVOCEANO Naval Oceanographic Office 

NAVPACMETOCCEN Naval Pacific Meteorology and Oceanography Center 

NAVTRAMETOCFAC Naval Training Meteorology and Oceanography Facility 

NCEP National Centers for Environmental Prediction (NOAA/NWS) 

NCO NCEP Central Operations 

NDBC National Data Buoy Center 

NESDIS National Environmental Satellite, Data, and Information Service 

NHC National Hurricane Center 

NHOP National Hurricane Operations Plan 

nm nautical miles 

NOAA National Oceanic and Atmospheric Administration 

NOM National Operations Manager (FAA) 

NOTAM Notice to Airmen 

NRL Naval Research Laboratory 

NSC NOAA Science Center 

NWS National Weather Service 

NWSOP National Winter Storms Operations Plan 

-OOAC Oceanic Aircraft Coordinator (USN) 

OB observation 

OFCM Office of the Federal Coordinator for Meteorological Services and 

 Supporting Research 

OM Operations Manager (FAA) 

OMIC Operations Manager In Charge (FAA) 
M-5 

OPC Ocean Prediction Center (NCEP) 

OSS Operations Support Squadron (USAF) 

-PPA Public Affairs 

PHFO ICAO identifier for Honolulu, HI 

POD Plan of the Day 

POES Polar-Orbiting Environmental Satellite 

-RRAPCON Radar Approach Control 

RECCO Reconnaissance Code 

RECON reconnaissance 

ROC Radar Operations Center 

RSMC Regional/Specialized Meteorological Center (WMO) 

-SSAA Special Activity Airspace 

SAB Satellite Analysis Branch 

SATCOM Satellite Communications 

SFC surface 

SIM Satellite Interpretation Message 

SLP Sea Level Pressure 

SPC Storm Prediction Center (NCEP) 

SSM/I Special Sensor Microwave Imager (DMSP) 

SSM/IS Special Sensor Microwave Imager Sounder 

SSM/T Special Sensor Microwave Temperature Sounder 

STMC Supervisory Traffic Management Coordinator (FAA) 

SUA Special Use Airspace 

-TTAFB Tropical Analysis Forecast Branch (NHC) 

TCA Aviation Tropical Cyclone Advisory 

TCD Tropical Cyclone Discussion 

TCE Tropical Cyclone Position Estimate 

TCM Tropical Cyclone Forecast/Advisories 

TCP Tropical Cyclone Public Advisory 

TCPOD Tropical Cyclone Plan of the Day 
M-6 

TCR Tropical Cyclone Reports 

TCS Tropical Cyclone Summary 

TCU Tropical Cyclone Update 

TCV Tropical Cyclone Watch Warning Product 

TD Tropical Depression 

TEMP temperature 

TEMP temporary 

TEMP DROP Dropwindsonde Code 

TF Thermal Fine 

TKO takeoff 

TMC Traffic Management Coordinator (FAA) 

T- number Tropical classification number 

TRMM Tropical Rainfall Measurement Mission 

TWD Tropical Weather Discussion 

TWO Tropical Weather Outlook 

TWS Tropical Weather Summary 

-UUAS Unmanned Aerial Systems 

UAV Unmanned Aerial Vehicle 

UCP unit control position (WSR-88D) 

UHF Ultra High Frequency 

US/U.S. United States 

USAF United States Air Force 

USCG United States Coast Guard 

USN United States Navy 

UTC Universal Coordinated Time 

-VVAS VISSR Atmospheric Sounder 

VCP volume coverage pattern (WSR-88D) 

VDM Vortex Data Message 

VIS Visible 

VIIRS Visible Infrared Imaging Radiometer 

-WWEFAX Weather Facsimile 

WFO Weather Forecast Office 

WMO World Meteorological Organization 

WND wind 
M-7 

WPMDS Weather Product Management and Distribution System (Offutt AFB) 

WRS Weather Reconnaissance Squadron 

WS Weather Squadron 

WSR-88D Weather Surveillance Radar-1988 Doppler 

WT Data type header for hurricane bulletins 

-ZZ Zulu (UTC)

N-1 

APPENDIX N 

GLOSSARY 

-AAgency. Any Federal agency or organization participating in the tropical cyclone forecasting and 

warning service. 

Airport Radar Service Area (ARSA). Regulatory airspace surrounding designated airports 

wherein ATC provides radar vectoring and sequencing on a full-time basis for all IFR and 

VFR aircraft. The service provided in an ARSA is called ARSA Service which includes: 

IFR/IFR-standard IFR separation; IFR/VFR-traffic advisories and conflict resolution; and 

VFR/VFR-traffic advisories and, as appropriate, safety alert. The Airman's Information 

Manual (AIM) contains an explanation of ARSA. The ARSA's are depicted on VFR 

aeronautical charts. 

Air Traffic Control System Command Center (ATCSCC). The FAA facility that monitors and 

manages the flow of air traffic throughout the National Airspace System (NAS), producing a 

safe, orderly, and expeditious flow of traffic while minimizing delays. The ATCSCC is a 24 

hour a day, 7 day a week operation. 

-CCenter Fix. The location of the center of a tropical or subtropical cyclone obtained by means 

other than reconnaissance aircraft penetration. See also Vortex Fix. 

Controlled Airspace. An airspace of defined dimensions within which air traffic control service 

is provided to IFR flights and to VFR flights in accordance with the airspace classification. 

a. Controlled airspace is a generic term that covers Class A, Class B, Class C, Class D, 

and Class E airspace. 

b. Controlled airspace is also that airspace within which all aircraft operators are subject 

to certain pilot qualifications, operating rules, and equipment requirements in 14 CFR 

Part 91 (for specific operating requirements, please refer to 14 CFR Part 91). For IFR 

operations in any class of controlled airspace, a pilot must file an IFR flight plan and 

receive an appropriate ATC clearance. Each Class B, Class C, and Class D airspace 

area designated for an airport contains at least one primary airport around which the 

airspace is designated (for specific designations and descriptions of the airspace 

classes, please refer to 14 CFR Part 71). 

c. Controlled airspace in the United States is designated as follows: 

CLASS A: Generally, that airspace from 18,000 feet MSL up to and including FL 600, including 

the airspace overlying the waters within 12 nautical miles of the coast of the 48 contiguous 

States and Alaska. Unless otherwise authorized, all persons must operate their aircraft under 

IFR. 
N-2 

CLASS B: Generally, that airspace from the surface to 10,000 feet MSL surrounding the 

nations's busiest airports in terms of airport operations or passenger enplanements. The 

configuration of each Class B airspace area is individually tailored and consists of a surface 

area and two or more layers (some Class B airspaces areas resemble upside-down wedding 

cakes), and is designed to contain all published instrument procedures once an aircraft enters 

the airspace. An ATC clearance is required for all aircraft to operate in the area, and all 

aircraft that are so cleared receive separation services within the airspace. The cloud clearance 

requirement for VFR operations is "clear of clouds." 

CLASS C: Generally, that airspace from the surface to 4,000 feet above the airport elevation 

(charted in MSL) surrounding those airports that have an operational control tower, are 

serviced by a radar approach control, and that have a certain number of IFR operations or 

passenger enplanements. Although the configuration of each Class C area is individually 

tailored, the airspace usually consists of a surface area with a 5 nautical mile (NM) radius, a 

circle with a 10 NM radius that extends no lower than 1,200 feet up to 4,000 feet above the 

airport elevation and an outer area. Each person must establish two-way radio 

communications with the ATC facility providing air traffic services prior to entering the 

airspace and thereafter maintain those communications while within the airspace. VFR 

aircraft are only separated from IFR aircraft within the airspace. 

CLASS D: Generally, that airspace from the surface to 2,500 feet above the airport elevation 

(charted in MSL) surrounding those airports that have an operational control tower. The 

configuration of each Class D airspace area is individually tailored and when instrument 

procedures are published, the airspace will normally be designed to contain the procedures. 

Arrival extensions for instrument approach procedures may be Class D or Class E airspace. 

Unless otherwise authorized, each person must establish two-way radio communications with 

the ATC facility providing air traffic services prior to entering the airspace and thereafter 

maintain those communications while in the airspace. No separation services are provided to 

VFR aircraft. 

CLASS E: Generally, if the airspace is not Class A, Class B, Class C, or Class D, and it is 

controlled airspace, it is Class E airspace. Class E airspace extends upward from either the 

surface or a designated altitude to the overlying or adjacent controlled airspace. When 

designated as a surface area, the airspace will be configured to contain all instrument 

procedures. Also in this class are Federal airways, airspace beginning at either 700 or 1,200 

AGL used to transition to/from the terminal or en route environment, en route domestic, and 

offshore airspace areas designated below 18,000 feet MSL. Unless designated at a lower 

altitude, Class E airspace begins at 14,500 MSL over the United States, including that 

airspace overlying the waters within 12 nautical miles of the 48 contiguous States and Alaska, 

up to, but not including 18,000 MSL, and the airspace above FL 600. 

Cyclone. An atmospheric closed circulation rotating counter-clockwise in the Northern 

Hemisphere. 
N-3 

-EExtratropical cyclone. A cyclone (of any intensity) for which the primary energy source is 

baroclinic (i.e., results from the temperature contrast between warm and cold air masses). 

Eye. The relatively calm center of the tropical cyclone that is more than one half surrounded by 

wall cloud. 

Eye Wall. An organized band of cumuliform clouds immediately surrounding the center of a 

tropical cyclone. Eye wall and wall cloud are used synonymously. 

-HHigh-Density/High-Accuracy (HD/HA) Data. Those data provided by automated airborne 

systems--WP-3s or WC-130s equipped with the Improved Weather Reconnaissance System. 

Hurricane/Typhoon. A warm-core tropical cyclone in which the maximum sustained surface 

wind speed (l-min mean) is 64 kt (74 mph) or more. 

Hurricane/Typhoon/Tropical Cyclone Season. The portion of the year having a relatively high 

incidence of hurricanes/typhoons/tropical cyclones. The seasons for the specific areas are as 

follows (Note: tropical cyclones can occur during any month of the year in the Western 

Pacific.): 

 Atlantic, Caribbean, 

 and the Gulf of Mexico June 1 to November 30 

 Eastern Pacific May 15 to November 30 

 Central Pacific June 1 to November 30 

 Western Pacific July 1 to December 31 

Hurricane Warning Offices. The designated hurricane warning offices follow: 

 National Hurricane Center, Miami, Florida 

 Central Pacific Hurricane Center, Honolulu, Hawaii 

Hurricane/Typhoon Warning. An announcement that sustained winds of 64 knots (74 mph or 

119 km/hr) or higher are expected within the specified coastal area. Because hurricane/ 

typhoon preparedness activities become difficult once winds reach tropical storm force, NHC, 

CPHC, and WFO Guam issue the hurricane/typhoon warning 36 hours in advance of the 

anticipated onset of tropical-storm-force winds. 

Hurricane/Typhoon Watch. An announcement that sustained winds of 64 knots (74 mph or 119 

km/hr) or higher are possible within the specified coastal area. Because hurricane/ typhoon 

preparedness activities become difficult once winds reach tropical storm force, NHC, CPHC, 
N-4 

and WFO Guam issue the hurricane/typhoon watch 48 hours in advance of the anticipated 

onset of tropical-storm-force winds. 

-IICAO-Controlled Airspace. An airspace of defined dimensions within which air traffic control 

service is provided to IFR flights and to VFR flights in accordance with the airspace 

classification. (Note: Controlled airspace is a generic term which covers Air Traffic Service 

airspace Classes A, B, C, D, and E). 

-MMajor Hurricane. A "major" hurricane is one that is classified as a Category 3 or higher. 

Maximum 1-Min Sustained Surface Wind. When applied to a particular weather system, refers 

to the highest 1-minute average wind (at an elevation on 10 meters with an unobstructed 

exposure) associated with that weather system at a particular point in time. 

Micronesia. An area defined by the Commonwealth of the Northern Marianas Islands, the 

Republic of Palau, the Federated States of Micronesia, and the Republic of the Marshall 

Islands. 

Miles. The term "miles" used in this plan refers to nautical miles (nm) unless otherwise 

indicated. 

Mission Identifier. The nomenclature assigned to tropical and subtropical cyclone aircraft 

reconnaissance missions for weather data identification. It's an agency-aircraft indicator 

followed by a Chief, Aerial Reconnaissance Coordination, All Hurricanes (CARCAH) 

assigned mission-system indicator. 

-NNational Operations Manager. Supervisor in charge of operations of the Air Traffic Control 

System Command Center. 

National Traffic Management Specialist. ATCSCC personnel responsible for the active 

management of traffic thoughout the NAS. 
N-5 

-OOperations Manager. Supervisor in charge of operations of an FAA Terminal Radar Approach 

Control (TRACON). 

Operations Manager in Charge. Supervisor in charge of operations of an FAA Air Route 

Traffic Control Center (ARTCC). 

-PPost-Tropical Cyclone. A former tropical cyclone. This generic term describes a cyclone that no 

longer possesses sufficient tropical characteristics to be considered a tropical cyclone. Posttropical cyclones can continue carrying heavy rains and high winds. Note that former tropical 

cyclones that have become fully extratropical, as well as remnant lows, are two specific 

classes of post-tropical cyclones. 

Present Movement. The best estimate of the movement of the center of a tropical cyclone at a 

given time and at a given position. This estimate does not reflect the short-period, small-scale 

oscillations of the cyclone center. 

-RReconnaissance Aircraft Sortie. A flight that meets the requirements of the tropical cyclone 

plan of the day. 

Relocated. A term used in an advisory to indicate that a vector drawn from the preceding 

advisory position to the latest known position is not necessarily a reasonable representation of 

the cyclone's movement. 

Remnant Low: A post-tropical cyclone that no longer possesses the convective organization 

required of a tropical cyclone and has maximum sustained winds of less than 34 kts. The term 

is most commonly applied to the nearly deep-convection-free swirls of stratocumulus in the 

eastern North Pacific. 

-SSpecial Activity Airspace. Any airspace with defined dimensions within the National Airspace 

System wherein limitations may be imposed upon aircraft operations. This airspace may be 

restricted areas, prohibited areas, military operations areas, air ATC assigned airspace, and 

any other designated airspace areas. The dimensions of this airspace are programmed into 

URET and can be designated as either active or inactive by screen entry. Aircraft trajectories 

are constantly tested against the applicable sectors when violations are predicted. 
N-6 

Special Use Airspace. Airspace of defined dimensions identified by an area on the surface of 

the earth wherein activities must be confined because of their nature and/or wherein 

limitations may be imposed upon aircraft operations that are not a part of those activities. 

Types of special use airspace are: 

a. Alert Area- Airspace which may contain a high volume of pilot training activities or 

an unusual type of aerial activity, neither of which is hazardous to aircraft. Alert Areas 

are depicted on aeronautical charts for the information of nonparticipating pilots. All 

activities within an Alert Area are conducted in accordance with Federal Aviation 

Regulations, and pilots of participating aircraft as well as pilots transiting the area are 

equally responsible for collision avoidance. 

b. Controlled Firing Area- Airspace wherein activities are conducted under conditions so 

controlled as to eliminate hazards to nonparticipating aircraft and to ensure the safety 

of persons and property on the ground. 

c. Military Operations Area (MOA)- A MOA is airspace established outside of Class A 

airspace area to separate or segregate certain nonhazardous military activities from 

IFR traffic and to identify for VFR traffic where these activities are conducted. 

(Refer to AIM.) 

d. Prohibited Area- Airspace designated under 14 CFR Part 73 within which no person 

may operate an aircraft without the permission of the using agency. 

(Refer to AIM.) 

(Refer to En Route Charts.) 

e. Restricted Area- Airspace designated under 14 CFR Part 73, within which the flight of 

aircraft, while not wholly prohibited, is subject to restriction. Most restricted areas are 

designated joint use and IFR/VFR operations in the area may be authorized by the 

controlling ATC facility when it is not being utilized by the using agency. Restricted 

areas are depicted on en route charts. Where joint use is authorized, the name of the 

ATC controlling facility is also shown. 

(Refer to 14 CFR Part 73.) 

(Refer to AIM.) 

f. Warning Area- A warning area is airspace of defined dimensions extending from 3 

nautical miles outward from the coast of the United States, that contains activity that 

may be hazardous to nonparticipating aircraft. The purpose of such warning area is to 

warn nonparticipating pilots of the potential danger. A warning area may be located 

over domestic or international waters or both. 
N-7 

Storm Surge. An abnormal rise in sea level accompanying a hurricane or other intense storm, 

and whose height is the difference between the observed level of the sea surface and the level 

that would have occurred in the absence of the cyclone. Storm surge is usually estimated by 

subtracting the normal or astronomic tide from the observed storm tide. 

Storm Tide. The actual level of sea water resulting from the astronomic tide combined with the 

storm surge. 

Subtropical Cyclone. A non-frontal low-pressure system that has characteristics of both tropical 

and extratropical cyclones. Like tropical cyclones, they are non-frontal, synoptic-scale 

cyclones that originate over tropical or subtropical waters, and have a closed surface wind 

circulation about a well-defined center. In addition, they have organized moderate to deep 

convection, but lack a central dense overcast. Unlike tropical cyclones, subtropical cyclones 

derive a significant proportion of their energy from baroclinic sources, and are generally coldcore in the upper troposphere, often being associated with an upper-level low or trough. In 

comparison to tropical cyclones, these systems generally have a radius of maximum winds 

occurring relatively far from the center (usually greater than 60 nm), and generally have a less 

symmetric wind field and distribution of convection. 

Subtropical Depression. A subtropical cyclone in which the maximum sustained surface wind 

speed (l-min mean) is 33 knots (38 mph) or less. 

Subtropical Storm. A subtropical cyclone in which the maximum sustained surface wind speed 

(1-min mean) is 34 knots (39 mph) or higher. 

Super Typhoon. A "super" typhoon is one that is classified as having winds of 130 knots (150 

mph) or greater. 

Sustained Surface Wind. The 1-minute averaged wind at the 10-meter elevation with an 

unobstructed exposure. 

Synoptic Surveillance (formerly Synoptic Track). Weather reconnaissance mission flown to 

provide vital meteorological information in data sparse ocean areas as a supplement to 

existing surface, radar, and satellite data. Synoptic flights better define the upper atmosphere 

and aid in the prediction of tropical cyclone motion and intensity. 

-TTropical Cyclone. A warm-core, non-frontal synoptic-scale cyclone, originating over tropical or 

subtropical waters, with organized deep convection and a closed surface wind circulation 

about a well-defined center. 

Tropical Cyclone Plan of the Day. A coordinated mission plan that tasks operational weather 

reconnaissance requirements during the next 1100 to 1100Z UTC day or as required, 

describes reconnaissance flights committed to satisfy both operational and research 
N-8 

requirements, and identifies possible reconnaissance requirements for the succeeding 24-hour 

period. 

Tropical Depression. A tropical cyclone in which the maximum sustained surface wind speed 

(l-min mean) is 33 kt (38 mph) or less. 

Tropical Disturbance. A discrete tropical weather system of apparently organized convection--

generally 100 to 300 mi in diameter--originating in the tropics or subtropics, having a 

nonfrontal migratory character, and maintaining its identity for 24 hours or more. It may or 

may not be associated with a detectable perturbation of the wind field. 

Tropical Storm. A tropical cyclone in which the maximum sustained surface wind speed (l-min 

mean) ranges from 34 kt (39 mph) to 63 kt (73 mph). 

Tropical Storm Warning. An announcement that sustained winds of 34 to 63 knots (39 to73 

mph or 63 to 118 km/hr) are expected within the specified coastal area. NHC, CPHC, and 

WFO Guam issue warnings when conditions along the coast are expected within 36 hours. 

Tropical Storm Watch. An announcement that sustained winds of 34 to 63 knots (39 to 73 mph 

or 63 to 118 km/hr) are possible within the specified coastal area. NHC, CPHC, and WFO 

Guam issue watches when conditions along the coast are possible within 48 hours. 

Tropical Wave. A trough or cyclonic curvature maximum in the trade-wind easterlies. The wave 

may reach maximum amplitude in the lower middle troposphere or may be the reflection of an 

upper tropospheric cold low or equatorial extension of a middle latitude trough. 

Tropical Weather System. A designation for one of a series of tropical weather anomalies. As 

such, it is the basic generic designation, which in successive stages of intensification, may be 

classified as a tropical disturbance, wave, depression, storm, or hurricane. 

Typhoon/Hurricane. A warm-core tropical cyclone in which the maximum sustained surface 

wind speed (l-min mean) is 64 kt (74 mph) or more. 

-UUncontrolled Airspace (Class G Airspace). That portion of the airspace that has not been 

designated as Class A, Class B, Class C, Class D, or Class E and within which Air Traffic 

Control has neither the authority nor the responsibility for exercising control over air traffic. 
N-9 

-VVortex Fix. The location of the surface and/or flight level center of a tropical or subtropical 

cyclone obtained by reconnaissance aircraft penetration. See Center Fix, also. 

-WWall Cloud. An organized band of cumuliform clouds immediately surrounding the center of a 

tropical cyclone. Wall cloud and eye wall are used synonymously.