OFFICE OF THE FEDERAL COORDINATOR FOR

METEOROLOGICAL SERVICES AND SUPPORTING RESEARCH

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

National Volcanic Ash

Operations Plan

for Aviation

National Volcanic Ash

Operations Plan

Washington, DC Washington, DC

August 2007 August 2007

FCM-P35-2007
 

THE FEDERAL COMMITTEE FOR 

 METEOROLOGICAL SERVICES AND SUPPORTING RESEARCH (FCMSSR) 

VADM CONRAD C. LAUTENBACHER, JR., USN (RET.) 

Chairman, Department of Commerce 

DR. SHARON L. HAYS 

Office of Science and Technology Policy 

DR. RAYMOND MOTHA 

Department of Agriculture 

DR. JACK HAYES 

Department of Commerce 

MR. ALAN SHAFFER 

Department of Defense 

DR. JERRY ELWOOD 

Department of Energy 

MR. KEVIN “SPANKY” KIRSCH 

Science and Technology Directorate 

Department of Homeland Security 

DR. MICHAEL SOUKUP 

Department of the Interior 

MR. RALPH BRAIBANTI 

Department of State 

MR. RANDOLPH LYON 

Office of Management and Budget 

MS. VICTORIA COX 

Department of Transportation 

MR. DAVID MAURSTAD 

Federal Emergency Management Agency 

Department of Homeland Security 

DR. S. ALAN STERN 

National Aeronautics and Space 

 Administration 

DR. JARVIS MOYERS (Acting) 

National Science Foundation 

MR. PAUL MISENCIK 

National Transportation Safety Board 

MR. MICHAEL JOHNSON 

U.S. Nuclear Regulatory Commission 

DR. LAWRENCE REITER 

Environmental Protection Agency 

MR. SAMUEL P. WILLIAMSON 

Federal Coordinator MR. JAMES B. HARRISON, Executive Secretary 

 Office of the Federal Coordinator for 

 Meteorological Services and Supporting Research 

 THE INTERDEPARTMENTAL COMMITTEE FOR 

METEOROLOGICAL SERVICES AND SUPPORTING RESEARCH (ICMSSR) 

 

MR. SAMUEL P. WILLIAMSON, Chairman 

Federal Coordinator 

MR. THOMAS PUTERBAUGH 

Department of Agriculture 

MS. VICKIE NADOLSKI (Acting) 

Department of Commerce 

RADM DAVID A. GOVE, 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. KEVIN “SPANKY” KIRSCH 

Science and Technology Directorate 

Department of Homeland Security 

MR. JOHN VIMONT 

Department of the Interior 

MR. ANTHONY FURST (Acting) 

Federal Highway Administration 

Department of Transportation 

MR. KENNETH M. LEONARD 

Federal Aviation Administration 

Department of Transportation 

DR. JONATHAN M. BERKSON 

United States Coast Guard 

Department of Homeland Security 

MR. JEFFREY MACLURE 

Department of State 

DR. S. T. RAO 

Environmental Protection Agency 

MR. DAN CATLETT (Acting) 

Federal Emergency Management Agency 

Department of Homeland Security 

DR. RAMESH KAKAR 

National Aeronautics and Space 

 Administration 

DR. JARVIS MOYERS 

National Science Foundation 

MR. DONALD E. EICK 

National Transportation Safety Board 

MS. LETA A. BROWN 

U.S. Nuclear Regulatory Commission 

MS. MELISSA N. BRANDT 

Office of Management and Budget 

 MR. JAMES B. HARRISON, Executive Secretary 

 Office of the Federal Coordinator for 

 Meteorological Services and Supporting Research 

Cover photograph courtesy USGS
 

i 

National Volcanic Ash 

Operations Plan for Aviation 

and 

Support of the ICAO International Airways 

Volcano Watch 

Office of the 

Federal Coordinator for Meteorological Services 

 and Supporting Research 

8455 Colesville Road, Suite 1500 

Silver Spring, Maryland 20910 

www.ofcm.gov 

301-427-2002 

FCM-P35-2007 

Washington, DC 

August 2007 
 

ii 
 

iii 

PREFACE 

The National Aviation Weather Program Strategic Plan (1997) and the National Aviation 

Weather Initiatives (1999) both identified volcanic ash as a high-priority informational need to 

aviation services. The risk to aviation from airborne volcanic ash is known and includes 

degraded engine performance (including flameout), loss of visibility, failure of critical 

navigational and operational instruments, and, in the worse case, loss of life. The immediate 

costs for aircraft encountering a dense plume are potentially major—damages up to $80 million 

have occurred to a single aircraft. Aircraft encountering less dense volcanic ash clouds can incur 

longer-term costs due to increased maintenance of engines and external surfaces. 

The overall goal, as stated in the Initiatives, is to eliminate encounters with ash that could 

degrade the in-flight safety of aircrews and passengers and cause damage to the aircraft. This 

goal can be accomplished by improving the ability to detect, track, and forecast hazardous ash 

clouds and to provide adequate warnings to the aviation community on the present and future 

location of the cloud. To reach this goal, the National Aviation Weather Program established 

three objectives: (1) prevention of accidental encounters with hazardous clouds; (2) reduction of 

air traffic delays, diversions, or evasive actions when hazardous clouds are present; and (3) the 

development of a single, worldwide standard for exchange of information on airborne hazardous 

materials. 

To that end, over the last several years, based on numerous documents (including an OFCMsponsored comprehensive study on aviation training and an update of Aviation Weather 

Programs/Projects), user forums, and two International Conferences on Volcanic Ash and 

Aviation Safety (1992 and 2004), the Working Group for Volcanic Ash (WG/VA), under the 

OFCM-sponsored Committee for Aviation Services and Research, developed the National 

Volcanic Ash Operations Plan for Aviation and Support of the International Civil Aviation 

Organization’s (ICAO) International Airways Volcano Watch. This plan defines agency 

responsibilities, provides a comprehensive description of an interagency standard for volcanic 

ash products and their formats, describes the agency backup procedures for operational products, 

and outlines the actions to be taken by each agency following an occurrence of a volcanic 

eruption that subsequently affects and impacts aviation services. 

Since our most recent International Conference on Volcanic Ash and Aviation Safety, volcanic 

ash-related product and service activities have grown considerably along with partnerships and 

alliances throughout the aviation community. In January 2005, the National Oceanic and 

Atmospheric Administration’s National Centers for Environment Prediction began running the 

Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model in place of the 

Volcanic Ash Forecast Transport and Dispersion (VAFTAD) model, upgrading support to the 

volcanic ash advisory community. Today, improvements to the HYSPLIT model are ongoing 

based on recommendations by the OFCM-sponsored Joint Action Group for the Selection and 

Evaluation of Atmospheric Transport and Diffusion Models and the Joint Action Group for 

Atmospheric Transport and Diffusion Modeling (Research and Development Plan). 

Two international workshops on volcanic ash have already taken place, noticeable improvements 

and innovations in education, training, and outreach have been made, and federal and public 

education and training programs on volcanic ash-related products, services, and procedures 
 

iv 

continue to evolve. For example, in partnership with Embry-Riddle Aeronautical University and 

other academic institutions, volcanic ash hazard and mitigation training has been incorporated 

into aviation meteorology courses. As an essential next step, our volcanic ash-related efforts in 

the near term will be centered on the development of an interagency implementation plan to 

document and address the most critical needs of the volcanic ash advisory community. 

This interagency plan, developed as the result of the cooperative efforts of six federal agencies, 

follows the guidelines in support of the ICAO International Airways Volcano Watch. The 

signatories on the next page are committed to volcanic ash operations for aviation and will work 

toward full implementation through agency programs, initiatives, and procedures. 

I extend my sincere thanks to all members of the WG/VA, subject-matter experts, and to my staff 

for their collaborative and cooperative efforts in developing this first-ever national volcanic ash 

operations plan. 

 //Signed// 

 

Samuel P. Williamson 

 Federal Coordinator for Meteorological Services 

 and Supporting Research 
 

v 

National Volcanic Ash Operations Plan for Aviation 

and 

Support of the ICAO International Airways Volcano Watch 

 //Signed// //Signed// 

_________________________________ ______________________________ 

Ms. Victoria Cox Col. Patrick M. Condray 

Vice President Commander 

Operations Planning Services Air Force Weather Agency 

Federal Aviation Administration United States Air Force 

Department of Transportation Department of Defense 

 //Signed// //Signed// 

________________________________ ______________________________ 

Dr. James E. Hoke Ms. Linda C. Gundersen 

Director (Acting) Chief Scientist for Geology 

Office of Climate, Water, and U.S. Geological Survey 

Weather Services Department of Interior 

National Weather Service 

National Oceanic and Atmospheric 

Administration 

Department of Commerce 

 

//Signed// //Signed// 

_________________________________ ______________________________ 

Dr. Steven S. Fine Ms. Kathy Kelly 

Director Director (Acting) 

Air Resources Laboratory Office of Satellite Data Processing 

Office of Oceanic and Atmospheric and Distribution 

Research National Environmental Satellite, Data, 

National Oceanic and Atmospheric and Information Service 

Administration National Oceanic and Atmospheric 

Department of Commerce Administration 

 Department of Commerce 

 

 //Signed// //Signed// 

_________________________________ ______________________________ 

Dr. Michael H. Freilich Mr. Lee Siebert

Director Director 

Earth Science Division Global Volcanism Program 

Science Mission Directorate Department of Mineral Sciences 

National Aeronautics and Space National Museum of Natural History 

Administration Smithsonian Institution 
 

vi 
 

vii 

The National Volcanic Ash Operations Plan for Aviation 

and 

Support of the ICAO International Airways Volcano Watch 

Table of Contents 

Preface ................................................................................................................................................. iii 

Table of Contents................................................................................................................................ vii 

1. Introduction and Background......................................................................................................... 1-1 

 1.0 Purpose. ................................................................................................................................. 1-1 

 1.1 Relation to Other Handbooks, Directives, and Manuals ....................................................... 1-1 

 1.2 Regional Volcanic Ash Operations Plans.............................................................................. 1-2 

 1.3 Format of this plan ................................................................................................................ 1-3 

 1.4 Changes to the Plan ............................................................................................................... 1-3 

 1.5 Agency Procedures and Procedural Changes ........................................................................ 1-3 

 1.6 Questions and Suggestions Regarding the Plan .................................................................... 1-3 

 

2. Responsibilities of Cooperating Agencies ..................................................................................... 2-1 

 2.0 General .................................................................................................................................. 2-1 

 2.1 Responsibilities of Federal Agencies .................................................................................... 2-1 

 2.1.1 Department of Commerce, National Oceanic and Atmospheric Administration......... 2-1 

 2.1.1.1 National Environmental Satellite, Data, and Information Service .................. 2-1 

 2.1.1.2 National Weather Service................................................................................ 2-1 

 2.1.1.3 Office of Oceanic and Atmospheric Research ................................................ 2-2 

2.1.2 Department of Defense, United States Air Force...................................................................... 2-2 

 2.1.3 Department of Interior, United States Geological Survey ........................................... 2-2 

 2.1.4 Department of Transportation, Federal Aviation Administration................................ 2-2 

 2.1.5 National Aeronautics and Space Administration ......................................................... 2-2 

 2.1.6 Smithsonian Institution ................................................................................................ 2-2 

3. Volcanic Ash Related Products...................................................................................................... 3-1 

 3.0 General .................................................................................................................................. 3-1 

 3.1 Observations.......................................................................................................................... 3-1 

 3.1.1 Meteorological Aerodrome Report (METAR) ............................................................ 3-1 

 3.1.2 Pilot Report (PIREP).................................................................................................... 3-1 

 3.1.3 Volcanic Activity Report (VAR) ................................................................................. 3-1 

 3.2 Advisories.............................................................................................................................. 3-1 

 3.2.1 Volcanic Ash Advisory (VAA) ................................................................................... 3-1 

 3.2.2 Volcanic Ash Graphic (VAG) ..................................................................................... 3-1 

 3.3 Inflight Weather Advisories/Warnings.................................................................................. 3-2 

 3.3.1 Center Weather Advisory (CWA)................................................................................ 3-2 

 3.3.2 Meteorological Impact Statement (MIS) ..................................................................... 3-2 
 

viii 

 3.3.3 Significant Meteorological Information (SIGMET) .................................................... 3-2 

 3.4 Notices................................................................................................................................... 3-2 

 3.4.1 Notice to Airmen (NOTAM) ....................................................................................... 3-2 

 3.4.2 Volcano Observatory Notice for Aviation (VONA).................................................... 3-2 

 3.5 Forecasts................................................................................................................................ 3-2 

 3.5.1 Area Forecast (FA) ...................................................................................................... 3-2 

 3.5.2 Terminal Aerodrome Forecast (TAF).......................................................................... 3-3 

 3.6 Model Output ........................................................................................................................ 3-3 

 3.6.1 Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT) ............ 3-3 

 

4. Operations and Procedures ............................................................................................................ 4-1 

 4.0 General .................................................................................................................................. 4-1 

 4.1 National Weather Service and National Environmental Satellite, Data, and 

 Information Service .............................................................................................................. 4-2 

 4.2 Department of Defense, United States Air Force.................................................................. 4-4 

 4.3 United States Geological Survey........................................................................................... 4-4 

 4.4 Federal Aviation Administration...........................................................................................4-7 

5. Observation and Message Report Formats .................................................................................... 5-1 

 5.0 General .................................................................................................................................. 5-1 

 5.1 Area Forecast (FA)................................................................................................................ 5-1 

 5.2 Aviation Routine Weather Report (METAR) and 

 Aviation Special Weather Report (SPECI) ........................................................................... 5-3 

 5.3 Center Weather Advisories (CWA)....................................................................................... 5-3 

 5.4 Meteorological Impact Statement (MIS)............................................................................... 5-3 

 5.5 Pilot Report (PIREP) ............................................................................................................. 5-4 

 5.6 SIGMET (WV)...................................................................................................................... 5-4 

 5.7 Terminal Aerodrome Forecast (TAF) ................................................................................... 5-5 

 5.8 Volcanic Ash Advisory (VAA)............................................................................................. 5-5 

 5.9 Volcanic Ash Graphic (VAG)............................................................................................... 5-7 

 5.10 Notice to Airmen (NOTAM)............................................................................................... 5-8 

 5.11 USGS Volcano Observatory Notice for Aviation (VONA) ................................................ 5-9 

 5.12 Volcanic Ash Report (VAR) (tentative)............................................................................ 5-11 

 

 
 

ix 

Figures and Tables 

Figure 4-1. Principal Exchange and Flow of Information for Volcanic Ash..................................... 4-1 

Figure 4-2. Areas of Responsibility for Washington, D.C. and Anchorage, AK VAACs................. 4-2 

Table 4-1. A description of USGS color-coded alert levels for aviation .......................................... 4-6 

Figure 5-1. Volcanic Ash Graphic ..................................................................................................... 5-8 

Figure 5-2. Volcanic Activity Report (tentative) ............................................................................. 5-11 

Appendices 

 A. Backup Operations 

 B. Transport and Dispersion Models 

 C. Acronyms and Terms 

 D. List of U.S. Volcanoes 
 

x 
 

 1-1 

Chapter 1 

Introduction and Background 

1.0 Purpose. The National Volcanic Ash Operations Plan for Aviation (NVAOPA) and 

Support of the International Civil Aviation Organization International Airways Volcano 

Watch supports the observing, tracking, monitoring, forecasting and reporting of volcanic 

ash in the atmosphere as it affects the safety of flight operations in the United States 

National Airspace System (NAS) for domestic and U.S. controlled international/oceanic 

service. This document identifies the federal agencies that implement these actions and 

describes their responsibilities, procedures/actions, and message formats. 

This document also provides information on how the Federal Aviation Administration 

(FAA), as the U.S. meteorological authority with regard to the International Civil 

Aviation Organization (ICAO), meets its obligations to the International Airways 

Volcano Watch (IAVW), which is sponsored by ICAO. 

Information on points of contact and useful Web sites are provided in this document. 

However, readers of this document are encouraged to visit the current Web sites to obtain 

the most current information on accessing information. Even though this document 

establishes the framework for operations, each agency has the responsibility to document 

its internal procedures for implementation of this plan. 

1.1 Relation to Other Handbooks, Directives, and Manuals 

The NVAOPA is consistent with agreements and publications of the World 

Meteorological Organization (WMO), ICAO, and civil as well as military weather 

services: 

International: 

• ICAO Annex 3, Meteorological Services for International Air Navigation 

• ICAO Annex 10, Aeronautical Communication 

• ICAO Annex 11, Air Traffic Services 

• ICAO Annex 15, Aeronautical Information Services 

• ICAO Handbook on the International Airways Volcano Watch (IAVW): 

 Operational Procedures and Contact List (Document 9766) 

• ICAO Manual on Volcanic Ash, Radioactive Material and Toxic Chemical Clouds 

 (Document 9691) 

• WMO No. 306 – Manual for Codes 

Domestic: 

• National Oceanic and Atmospheric Administration’s National Weather Service 

 Directives, series 10-8 Aviation Weather Services, available at 

 http://www.nws.noaa.gov/directives. 

• FMH-12, Federal Meteorological Handbook No. 12 - United States Meteorological 

 Codes and Coding Practices, available at 

 http://www.ofcm.gov/fmh12/frontpage.htm
 

 1-2 

• FMH-1, Federal Meteorological Handbook No. 1 - Surface Weather Observations 

 and Reports, available at http://www.ofcm.gov/fmh-1/fmh1.htm.

• FAA Order 7110.10: Flight Service 

• FAA Order 7110.65: Air Traffic Control 

• FAA Order 7930.2: Notices to AIRMEN 

• FAA Order 7900.5: Surface Weather Observing 

• FAA Aeronautical Information Manual 

• FAA Aeronautical Information Publication 

• FAA AC-00-45E, Aviation Weather Services 

• FAA AC-00-6A, Aviation Weather for Pilots and Flight Operations Personnel 

• FAA 8400.10, Handbook for Principal Operating Inspector

1.2 Regional Volcanic Ash Operations Plans. In addition to the National Volcanic 

Ash Operations Plan for Aviation, there are two separate and distinct regional plans 

which provide operational guidance, supplemental information, and more detail at the 

regional level for volcanic ash operations in response to volcanic ash episodes and 

hazards in the Alaskan and Northern Marianas Islands regions. 

a. The Interagency Operating Plan for Volcanic Ash Episodes in Alaska 

This plan provides an overview of integrated operations among multiple agencies in 

response to the threat of volcanic ash affecting Alaska, and an agency-by-agency 

description of roles and responsibilities in such events. The agencies involved in this 

operating plan are: the Federal Aviation Administration (FAA); the Alaska Volcano 

Observatory (AVO) operated jointly by the United States Geological Survey (USGS), 

Alaska Division of Geological and Geophysical Surveys (ADGGS) and the University of 

Alaska Fairbanks Geophysical Institute (UAFGI); the National Weather Service (NWS); 

the Department of Defense (DOD); the State Division of Homeland Security and 

Emergency Management (DHS&EM); and the United States Coast Guard (USCG). It 

covers the State of Alaska and the adjacent United States airspace Flight Information 

Regions (FIR). It also includes responsibility for volcanic ash transported by upper 

winds from erupting volcanoes outside the United States FIRs into the Alaska airspace, 

such as those in Kamchatka and the Kurile Islands, Russia. To access this plan, please go 

to http://aawu.arh.noaa.gov/interagency/interagency_plan.pdf or contact NWS Alaska 

Region Headquarters, ESSD Administration, 907-271-3508. 

 b. The Interagency Operating Plan for Volcanic Ash Hazards to Aviation in the 

Pacific Region of the Northern Marianas Islands 

This plan provides operational guidelines in support of the detection, observation, 

tracking, and reporting of airborne volcanic ash as it affects the safety of flight operations 

in the region of the Northern Mariana Islands airspace. It outlines a framework for 

interaction among the pertinent federal and local agencies within the context of the 

International Airways Volcano Watch (IAVW) developed by the International Civil 

Aviation Organization (ICAO). It also addresses the responsibilities, operational 

procedures/actions, and information products of each agency that supports the IAVW. 

This plan refines and codifies the necessary procedures to provide reliable, consistent 

ash-hazard information to the aviation sector in the Marianas region. To access this plan, 
 

 1-3 

please contact the USGS Volcano Hazard Program, 703-648-6712. 

1.3 Format of this plan 

Chapter 2 presents an overview of the responsibilities of the cooperating agencies in 

support of the NVAOPA. 

Chapter 3 presents a listing of operational products related to volcanic ash in support of 

aviation operations. 

Chapter 4 discusses general operations and procedures to carry out each agency’s mission 

related to volcanic ash in support of aviation operations. 

Chapter 5 provides examples of operational products related to volcanic ash in support of 

aviation operations. 

Appendix A outlines agency backup operational procedures. 

Appendix B discusses transport and dispersion models. 

Appendix C defines the acronyms and terms used in this plan. 

Appendix D is a list of U.S. Volcanoes with associated Air-Route-Traffic Control 

Centers, Meteorological Watch Offices, and Weather Forecast Offices. 

1.4 Changes to The Plan 

 

Changes, additions, deletions, and corrections will be issued, as necessary. These 

changes shall be issued only by the Office of the Federal Coordinator for Meteorology 

after consultation and coordination with the Working Group for Volcanic Ash. 

1.5 Agency Procedures and Procedural Changes 

 

Individual agencies issue their own manuals and directives defining their procedures 

which implement the NVAOPA. Such manuals shall complement, not change, the 

operational procedures contained within this document. 

1.6 Questions and Suggestions Regarding the Plan 

Questions or suggestions about the content/organization of the Plan should be directed to: 

The Office of the Federal Coordinator for Meteorology 

8455 Colesville Road, Suite 1500 

Silver Spring, MD 20910 

Telephone: Commercial (301) 427-2002 

 FAX (301) 427-2007 

 DSN 851-1460 
 

 1-4 
 

2- 1

Chapter 2 

Responsibilities of Cooperating Agencies 

2.0 General. There are four principal federal agencies that support the NVAOPA: 

• Department of Commerce, National Oceanic and Atmospheric 

 Administration 

• Department of Defense, United States Air Force 

• Department of Interior, United States Geologic Survey 

• Department of Transportation, Federal Aviation Administration 

The National Aeronautics and Space Administration and the Smithsonian Institution also 

provide support to the federal agencies through extending the benefits of earth science 

research in the areas of volcanic ash observation, tracking, and eruption characteristics. 

In addition, the Smithsonian Institution archives information on volcanoes, not only in 

the United States, but globally. 

2.1 Responsibilities of Federal Agencies 

2.1.1 Department of Commerce, National Oceanic and Atmospheric 

Administration (NOAA). NOAA is responsible for the operational monitoring of the 

state of the atmosphere, including the presence of volcanic ash clouds injected into the 

atmosphere by eruptions. NOAA, through several of its line offices, maintains the 

observational, analytical, and forecasting capabilities required to estimate the location 

and movement of volcanic ash clouds throughout its areas of responsibility.

2.1.1.1 National Environmental Satellite, Data, and Information 

Service (NESDIS). The Satellite Analysis Branch of NESDIS operates the 

Washington Volcanic Ash Advisory Center (VAAC) in conjunction with the 

National Weather Service, National Centers for Environmental Prediction 

(NCEP). 

2.1.1.2 National Weather Service (NWS). NOAA’s NWS operates the 

Anchorage VAAC and shares the responsibility of operating the Washington 

VAAC with NESDIS. The NWS operates: 

• The ICAO-stipulated World Area Forecast Center (WAFC) 

• Three Meteorological Watch Offices (MWO) located in Anchorage, 

Honolulu, and Kansas City 

• Numerous Weather Forecast Offices (WFO) 

• Numerous Center Weather Service Units (CWSU) in support of 

FAA Air Route Traffic Control Centers (ARTCC). 

Through these units, the NWS provides forecasts, advisories, and warnings for 

volcanic ash. 
 

2- 2

2.1.1.3 Office of Oceanic and Atmospheric Research. The Office of 

Oceanic and Atmospheric Research’s Air Resources Laboratory conducts 

supporting research to improve dispersion forecast guidance and is responsible for 

transferring updated dispersion modeling capabilities to the NWS NCEP. Air 

Resources Laboratory developed the HYbrid Single-Particle Lagrangian 

Integrated Trajectory (HYSPLIT) dispersion model that is used operationally at 

NCEP. 

2.1.2 Department of Defense, United States Air Force (USAF). The USAF 

through its 2nd Weather Group, Air Force Weather Agency (AFWA), Offutt Air Force 

Base, Nebraska, is the DOD focal point for volcanic ash advisories and forecasts. 

AFWA is responsible for issuing advisory text messages and providing imagery analysis 

and forecast visualization products for U.S. forces worldwide.

2.1.3 Department of Interior, United States Geological Survey (USGS). The 

USGS has the federal responsibility to issue disaster warnings for earthquakes, volcanic 

eruptions, landslides, or other geologic catastrophes. The USGS provides eruption 

warnings and related notifications based on data and observations collected from 

extensive monitoring networks operated by five U.S. volcano observatories supported 

primarily by the USGS Volcano Hazards Program. 

2.1.4 Department of Transportation, Federal Aviation Administration 

(FAA). FAA is responsible for issuing and disseminating Notices to Airmen (NOTAM) 

when notified of precursory volcanic unrest, eruptive activity, or volcanic ash in the 

NAS. In addition, the FAA, through its communication network, disseminates 

information on volcanic ash to Airline Operations Centers (AOC), ARTCC, Terminal 

Radar Approach Control (TRACON), Flight Service Stations (FSS), towers, System 

Operations, and other users of the NAS. 

2.1.5 National Aeronautics and Space Administration (NASA). NASA 

supports space-based observation and tracking of ash plumes and volcanic gases through 

the use of earth-observing research satellites. NASA sensors that can characterize 

volcanic ash include: the Moderate Resolution Imaging Spectroradiometer, the Ozone 

Monitoring Instrument, and the Tropospheric Emission Spectrometer. 

In collaboration with the FAA Aviation Weather Research Program, NASA 

provides satellite observations for research on volcanic ash detection. NASA’s research 

capabilities are transferred to operational forecasting tools as worked out in agreements 

with other agencies. Through competitive solicitations, NASA actively seeks to expand 

its research network for satellite observations of volcanic ash activity. 

2.1.6 Smithsonian Institution (SI). The SI Global Volcanism Program (GVP), 

housed within the Mineral Sciences Department of the Natural History Museum, 

maintains a database on eruption histories and characteristics of the world’s volcanoes. 

The GVP also publishes books and weekly and monthly reports on volcanoes, collects 

maps, specimens, photos, and video, and provides handbooks and compilations in support 

of understanding Earth’s 1,500 volcanoes with known or possible eruptions in the past 
 

2- 3

10,000 years. The Program has a small staff generally in the Washington, D.C., office 

during normal business hours (9:00 a.m.-5:00 p.m., Monday-Friday, excluding federal 

holidays). 
 

2- 4
 

3- 1

Chapter 3 

Volcanic Ash Related Products 

 

3.0 General. The following is a list of products that may contain volcanic ash or 

volcanic activity information in support of aviation operations. These products are 

categorized as: observations, advisories, inflight weather advisories/warnings, notices, 

forecasts, and model output. Examples of these products in their unique message formats 

are in Chapter 5. 

 

3.1 Observations 

3.1.1 METAR: METeorological Aerodrome Report. An international code 

(Aviation Routine Weather Report) used for reporting, recording and transmitting 

weather observations. 

 3.1.1a SPECI: In the METAR observation program, a surface 

observation issued on a non-routine basis as dictated by changing meteorological 

conditions. Volcanic ash observed at an aerodrome or in the vicinity of an aerodrome is 

normally reported in this report. 

3.1.2 PIREP: Pilot Report. A report of inflight weather by an aircraft pilot or 

crew member. Pilots who observe volcanic ash can report the information in an AIREP 

or PIREP. When volcanic ash information is issued in a PIREP the report is referred to 

as an Urgent PIREP. 

 3.1.2a AIREP: Aircraft Report. A report from an aircraft in flight 

prepared in conformity with requirements for position, and operational and/or 

meteorological reporting. An AIREP is an inflight evaluation usually made over areas 

where weather information is limited or non-existent (for example, over an ocean). 

3.1.3 VAR: Volcanic Activity Report. A report of volcanic ash similar in format 

to a PIREP. However, the VAR may include additional information on the physical 

characteristics of the ash. It may also be a special AIREP with a supplemental section 

that describes the ash cloud. Pilots normally provide VAR information immediately 

upon completion of flight operations or during flight debriefings. (Note: per guidance in 

the Aeronautical Information Manual, items 1-8 of the VAR are to be transmitted 

immediately to the ARTCC.) 

3.2 Advisories 

3.2.1 VAA: Volcanic Ash Advisory. Information issued by a Volcanic Ash 

Advisory Center concerning the occurrence or expected occurrence of volcanic ash that 

may affect the safety of aircraft operations. A VAA is a text message that identifies the 

volcano, time of eruption, observed position of the ash cloud, and the forecasted position 

of the ash. The VAA is not to be used as a warning message. 

3.2.2 VAG: Volcanic Ash Graphic. A graphical depiction of the Volcanic Ash 

Advisory (VAA). 
 

3- 2

3.3 Inflight Weather Advisories/Warnings 

3.3.1 CWA: Center Weather Advisory. The CWA is a 0-2 hour (valid up to 2 

hours after issuance) aviation weather warning primarily used by pilots to anticipate and 

avoid adverse weather conditions in the en route and terminal environments.

3.3.2 MIS: Meteorological Impact Statement. An unscheduled flow control and 

flight operations planning forecast. It is a 2-12 hour (valid up to 12 hours after issuance) 

briefing and forecast product at ARTCC, Air Traffic Control System Command Center 

(ATCSCC), TRACON, and the Air Traffic Control Towers (ATCT) responsible for making 

flow-control type decisions. 

3.3.3 SIGMET: SIGnificant METeorological Information. SIGMET is a brief 

description of the occurrence and/or expected occurrence of specified en route weather 

phenomena that may affect the safety of all aircraft operations (e.g. occurrence or 

expected occurrence of a volcanic ash cloud). 

3.4 Notices 

3.4.1 NOTAM: Notice to Airmen. A notice containing information concerning 

the establishment, condition or change in any aeronautical facility, service, procedure or 

hazard, the timely knowledge of which is essential to personnel concerned with flight 

operations. Information related to the pre-eruption or eruptive stage of a volcano can be 

reported in a NOTAM. Included in a NOTAM is the color code, which is provided by a 

Volcano Observatory (VO). The NOTAM Office normally issues a NOTAM based on 

information as provided by the ARTCC. 

3.4.2 VONA: Volcano Observatory Notice for Aviation. A short message in 

structured format issued by a USGS Volcanic Observatory to describe volcanic activity to 

the aviation sector, highlighting ash-plume information and including the aviation color 

code. The VONA is provided to the appropriate ARTCC, MWO, and VAAC in support 

of the issuance of NOTAM, VAA, VAG, and SIGMET, as well as to AFWA to support 

DOD advisories. 

3.5 Forecasts 

3.5.1 FA: Area Forecast. Forecast issued by the MWO which describes weather 

conditions specific to aviation interests. Each FA contains a synopsis, forecast, and 

outlook portion. FA issuance times and forecast periods vary somewhat due to customer 

requirements. The FA will describe, in abbreviated language, specified en route weather 

phenomena below FL450. FAs are produced for the following areas: 

• Six (6) geographical areas in the Continental United States (CONUS) and 

adjacent coastal waters 

• Hawaiian Islands and coastal waters (out to 40 nm from the coastline) 

• State of Alaska and coastal waters of Alaska. 
 

3- 3

3.5.2 TAF: Terminal Aerodrome Forecast. A forecast of meteorological 

conditions significant to aviation at an airport location (location within 5 nm of center of 

the airport’s runway complex). These forecasts are issued by NWS and DOD every 6 

hours with amendments issued as needed. 

3.6 Model Output 

3.6.1 HYSPLIT: The HYbrid Single-Particle Lagrangian Integrated Trajectory 

model. HYSPLIT forecast transport and dispersion model output is issued by the NWS as 

guidance. 
 

3- 4
 

4-1 

Chapter 4 

Operations and Procedures 

4.0 General. Every effort has been made to standardize terminology, adopt common 

definitions, and adjust criteria to a common base; however, each agency has different 

operational criteria that must be met. Standardization is used wherever possible in 

advisories, forecasts and warnings; however, each agency retains the right to specify the 

criteria needed to carry out its mission. Figure 4-1 shows the principal exchange and 

flow of products and information for volcanic ash. 

VONA, PIREP, 

VAR, Smithsonian, 

Satellite, MWO 

VAAC 

Anchorage 

Or 

Washington 

National Weather Service 

Telecommunications Gateway 

and 

Weather Message Switching 

Center Replacement 

FAA 

ARTCC 

Flight Service 

NOTAM Office 

MWO 

Kansas City, 

Anchorage, 

Honolulu 

WAFS 

• VAA 

• SIGMET 

• VAG 

• NOTAM 

• SIGWX 

USGS VO 

Cascades 

Alaska 

Hawaii 

Long Valley 

Yellowstone 

Washington and London 

World Area Forecast 

Centers 

End User

Dispatcher 

Pilot 

Controller 

Airport Manager 

Source of Information 

Multiple Circuits 

ICAO VAAC 

Tokyo, Darwin, Montreal, 

Wellington, Toulouse, London, 

and Buenos Aires, 

Air Force 

 Weather Agency 

Figure 4-1. Principal Exchange and Flow of Information for Volcanic Ash. This flow diagram shows the 

principal routes that information will flow between units/offices for the issuance of a VAA, VAG, SIGMET, 

NOTAM, VONA, PIREP, or VAR. Information can enter at various points on the diagram. It is not to imply that 

these are the only approved means of routing information but rather to convey who is required to have information 

available and their primary source for the information.
 

4-2 

4.1 National Weather Service and National Environmental Satellite, Data, and 

Information Service 

4.1.1 General. The NWS and NESDIS have the responsibility for providing 

warnings or advisories for the CONUS, coastal waters, U.S. controlled oceanic flight 

information regions (FIR), and Alaska. This responsibility is fulfilled by the 

NCEP/Aviation Weather Center, WFO, CWSU, MWO, and VAAC. The NWS also has 

responsibility to disseminate reports, warnings and advisories. 

4.1.2 Operations and Procedures. The Anchorage and Washington VAAC are 

staffed 24 hours per day, 7 days per week to provide guidance and support to MWO and 

the aviation community (Fig. 4-2). Duty meteorologists are tasked to monitor remote 

sensing data, PIREPs, and reports from the VO and aviation community on a continuous 

basis. The VAAC are also tasked to run the ash dispersion models, determine current and 

forecast area extent of the ash, and produce VAA and VAG for its customers. The MWO 

are responsible for issuing the volcanic ash SIGMET (WV). 

4.1.2.1 Volcanic Ash Advisory Centers. The Washington and Anchorage 

VAAC each issue VAA and VAG as support and guidance to the MWO for 

issuance of WV. 

Upon detection of volcanic ash in satellite imagery or upon receipt of a report of volcanic 

activity or ash from a bona fide source, the VAAC will: 

• Review/analyze satellite images and other data sets of the area for the time of the 

event to confirm the presence of a volcanic ash cloud and, if possible, its extent. 

• Prepare and issue advisory information (VAA/VAG) on the observed and 

forecasted location of the volcanic ash cloud, in both text and graphical format, for 

transmission to the MWO and ARTCC. 

Figure 4-2. The area of responsibility for the Washington, D.C. (red) and Anchorage, AK (blue) VAACs.
 

4-3 

• As needed, initiate the NOAA volcanic ash dispersion model (HYSPLIT; see 

appendix B) in order to provide guidance in preparing the VAA/VAG. 

The VAAC will monitor subsequent satellite information to assist in tracking the 

movement of ash clouds, updating of advisory information to the MWO, ARTCC, and 

AOC at intervals of at least 6 hours, or sooner, until the ash cloud is no longer 

identifiable from satellite imagery or no further reports of volcanic ash or further 

eruptions have been received. 

4.1.2.2 Meteorological Watch Offices. There are three MWOs in the 

United States: Anchorage, Alaska; Honolulu, Hawaii; and Kansas City, Missouri. 

The Kansas City MWO is also known as the Aviation Weather Center and the 

Anchorage MWO is known as the Alaska Aviation Weather Unit. The MWO is 

responsible for the issuance of a SIGMET for volcanic ash. Upon receipt of 

information concerning a volcanic eruption and/or the existence of a volcanic ash 

cloud, the MWO: 

• Issues a SIGMET; 

• Amends the FA, if appropriate; 

• Notifies the VAAC; and 

• Advises the ARTCC/Flight Service Station (FSS) whether or not ash is identifiable 

on satellite and provide any follow-up information concerning both horizontal and 

vertical extent of the ash plume. 

Alaska only: In addition to the SIGMET, the MWO will amend the Area Forecast if 

applicable to include reference to the SIGMET. 

The Kansas City MWO supports: 

• 20 ARTCC in the conterminous United States including coastal waters 

• New York, Miami, San Juan Oceanic FIRs 

• Oakland Oceanic FIR north of 30 degrees N latitude, and the portion east of 140 

degrees west longitude, which is between the equator and 30 degrees north latitude 

The Honolulu MWO is responsible for the Oakland Oceanic FIR south of 30 degrees 

north, and between 140 west and 130 east longitude. 

The Anchorage MWO supports the Anchorage FIR. 

Current SIGMET information can be found at: http://aviationweather.noaa.gov/ 

4.1.2.3 Weather Forecast Offices. The WFO are responsible for issuing 

the TAF for select locations. These forecasts cover a five (5) nautical mile radius 

around the center point of the runway complex and they are issued every 6 hours 

with amendments as needed. Under the NWS directive 10-5 series, the WFO also 
 

4-4 

issue Ashfall Advisories and under the 10-3 series, the WFO issue marine weather 

statements that include ash information. 

4.1.2.4 Center Weather Service Units. The CWSU prepares the Center 

Weather Advisory (CWA) supporting the ARTCC in the NAS. The CWSU 

provides advisories of hazardous weather conditions for airborne aircraft. The 

role of the CWSU during a volcanic eruption will depend somewhat on the 

situation and flow of information. When an initial report of an eruption is 

received at the ARTCC, the CWSU meteorologist or designee will enter the 

report as an URGENT PIREP (UUA). The CWSU meteorologist will then call 

the MWO to relay the volcano information. 

4.2 Department of Defense/United States Air Force 

4.2.1 General. The U.S. Air Force through its 2nd Weather Group, Air Force 

Weather Agency (AFWA), Offutt Air Force Base, Nebraska, is the DOD focal point for 

volcanic ash advisories and forecasts. AFWA is responsible for issuing a specialized set 

of advisory text, imagery analysis and forecast visualization graphics products for U.S. 

Forces worldwide. It also provides a backup for the Washington VAAC in case of 

disruptions to ensure continuity of operations. 

4.2.2 Operations and Procedures. 

4.2.2.1 AFWA. The Meteorological Satellite (METSAT) Applications 

Weather Flight at 2nd Weather Group issues volcanic ash guidance products for 

the DOD. These products include text advisories incorporating information from 

NOAA VAA and SIGMET and USGS VONA. These products also include 

forecast ash trajectory outputs in both animation and static panel format utilizing 

tailored interactive graphic visualizations of Puff model trajectory forecasts and 

satellite imagery analysis. 

AFWA will notify the appropriate VAAC if it detects an ash plume in imagery 

surveillance, or other observational data, and has not received a VAA message. AFWA 

will also notify the VAAC if imagery analysis or other data suggests different 

conclusions than indicated in the VAA. 

When functioning as the backup for the Washington VAAC, AFWA will issue a VAA 

and produce a Volcanic Ash Forecast Transport and Dispersion model format graphic 

look-alike based on Puff. The VAG is not provided in backup mode. 

4.3 United States Geological Survey 

4.3.1 General. The USGS gathers and interprets volcano data from its 

observatory monitoring networks and any other relevant sources and provides notices of 

significant precursory unrest and the onset and cessation of eruptive activity. The USGS 

has five Volcano Observatories (VO) located as follows: 
 

4-5 

• The Hawaiian Volcano Observatory (HVO) on Hawaii Island monitors 

volcanoes on the islands of Hawaii and Maui and shares monitoring in the 

Northern Mariana Islands with other VO. 

• The Cascades Volcano Observatory (CVO) in Vancouver, Washington, 

monitors the Cascade Range volcanoes in Washington, Oregon, and Northern 

California. CVO partners with the University of Washington to conduct seismic 

monitoring in the Cascades. CVO also shares monitoring in the Northern 

Mariana Islands. 

• The Alaska Volcano Observatory (AVO) monitors Alaskan volcanoes in 

partnership with the University of Alaska Fairbanks Geophysical Institute and 

State of Alaska Division of Geological and Geophysical Surveys. AVO also 

coordinates monitoring in the Northern Mariana Islands. 

• The Long Valley Observatory monitors the Long Valley caldera in California 

and supports CVO with monitoring of Cascade volcanoes in California. 

• The Yellowstone Volcano Observatory, a collaborative effort of the USGS 

Volcano Hazards Program, the University of Utah, and Yellowstone National 

Park, monitors the Yellowstone caldera. 

4.3.2 Operations and Procedures 

Each VO is headed by a Scientist-in-Charge who is responsible for the overall monitoring 

effort and for determining alert levels for volcanoes monitored by a particular 

observatory. USGS VO are not staffed 24/7 on a routine basis, although duty scientists 

carry beepers and phones to receive automatic notification when data levels recorded on 

key geophysical sensors exceed pre-set thresholds. The VO operate 24/7 watches only 

during periods of extreme unrest or eruption. 

 

4.3.2.1 Volcano Observatories. The principal role of the VO in support 

of aviation is to alert ARTCC, MWO, and VAAC of significant precursory 

volcanic unrest or eruptive activity, including information about ash plumes. 

Information provided by the VO is used by FAA in the preparation of a NOTAM 

on the status of the volcano, by MWO in issuance of WV, and by VAAC in 

issuance of VAA and VAG. 

For the aviation sector, in accord with recommended ICAO procedures, VO issue 

color-coded alert levels – Green, Yellow, Orange, and Red – focused on airborne 

ash hazards (see Table 4-1). Color codes reflect conditions at the volcano and 

depend upon monitoring data and interpretation of changing phenomena. A 

telephone “call down” is implemented when alert levels are raised or lowered and 

when an ash-producing event occurs, in the following order of priority: 

1. The appropriate ARTCC Operations Manager 

2. The appropriate MWO 

3. Washington or Anchorage VAAC 

4. AFWA 

5. The appropriate WFO 
 

4-6 

 Table 4-1. A description of USGS color-coded alert levels for aviation. 

4.3.2.2 Volcano Observatory Notice for Aviation. The aviation color 

code assigned by the VO is incorporated into the text of a VONA (format in 

section 5.12). VONA are issued when color codes change (up or down) or within 

a color code when a significant change, such as an ash-producing event, occurs in 

volcanic activity. VONA are provided to the appropriate ARTCC, MWO, and 

VAAC by faxes on commercial communication networks and by emails over the 

public Internet. 

4.3.2.3 Other VO Information. To supplement the VONA, VO also 

provide information in addition to what is incorporated into a NOTAM as well as 

information about low-level unrest (color code Yellow) that may not warrant 

issuance of a NOTAM. This information is available on the publicly accessible 

Web site http://volcanoes.usgs.gov. 

AVIATION COLOR CODES 

GREEN Volcano is in normal, non-eruptive state. 

 or, after a change from a higher level: 

Volcanic activity considered to have ceased, and volcano reverted to its 

normal, non-eruptive state. 

YELLOW Volcano is exhibiting signs of elevated unrest above known background 

levels. 

 or, after a change from higher level: 

Volcanic activity has decreased significantly but continues to be closely 

monitored for possible renewed increase. 

ORANGE Volcano is exhibiting heightened unrest with increased likelihood of 

eruption, 

 or, 

Volcanic eruption is underway with no or minor ash emission [specify ashplume height if possible]. 

RED Eruption is forecast to be imminent with significant emission of ash into the 

atmosphere likely. 

 or, 

Eruption is underway with significant emission of ash into the atmosphere 

[specify ash-plume height if possible]. 
 

4-7 

4.4 Federal Aviation Administration 

4.4.1 General. The FAA has the responsibility to ensure that all provisions of 

meteorological services are provided to users of the NAS which includes the 

dissemination and distribution of observations, forecasts, and warning messages that 

pertain to volcanic ash. In addition, the FAA is responsible for issuing a NOTAM on the 

status of a volcano during pre-eruption and eruption phases. 

4.4.2 Operations and Procedures 

4.4.2.1 Air Route Traffic Control Center. The FAA ARTCC is 

responsible for all activities within its designated airspace and for determining if a 

hazard(s) will affect its operations. The Operations Manager, upon receipt of a 

PIREP or other valid source of volcanic activity, should first verify that 

information with the respective VO (see appendix D). When an Operations 

Manager receives volcanic information listed in section 3.1 directly from a VO, 

the following procedures are recommended (note: local facility orders may 

supersede these procedures): 

A) Notify the following key personnel: 

• Center Weather Service Unit Meteorologist, or designee. 

• ATCSCC National Operations Manager (NOM). 

• Traffic Management Unit Officer/Weather Coordinator. 

• FAA Regional Operations Center. 

• ARTCC Facility Manager. 

• Watch Supervisor of the Automated Flight Service Station (AFSS)/FSS 

nearest the volcanic activity. 

• Watch Supervisors of any affected TRACON and Tower. 

• Systems Operations Center Maintenance Control Center. 

• Air Traffic Control System Command Center. 

• Military Base Operations (if appropriate). 

B) Issue a Flight Data Center (FDC) NOTAM, using the information received 

from the VO, in the prescribed format listed in Chapter 5, Paragraph 5.11. 

Forward this NOTAM to the U.S. NOTAM Office (USNOF) via the NOTAM 

Entry System, Fax, or Commercial Phone for national/international 

dissemination. USNOF will disseminate FDC NOTAM nationally (and 

internationally if appropriate). NOTAM information is available to the public 

at: https://pilotweb.nas.faa.gov 

C) The Operations Supervisor In Charge (OSIC)/Controller In Charge (CIC) will 

ensure that: 

• PIREPs are solicited by controllers. 

• NOTAM and PIREP information is disseminated to controllers on duty 

in a timely manner. 
 

4-8 

• Forward Urgent PIREP for volcanic ash to CWSU/Weather Coordinator 

for dissemination. 

D) Traffic Management personnel will: 

• Review affected areas for required traffic management initiatives and 

coordinate with the ATCSCC and all affected facilities. 

E) Controllers will: 

 Provide to aircraft the most current information available 

(SIGMET, CWA, MIS, PIREP) concerning the ash cloud position, 

altitude and movement. 

 Suggest headings and re-routes around known ash or possible ash 

areas. 

 Assist Visual Flight Rules aircraft to the extent possible in 

avoiding ash cloud areas. 

 Solicit PIREP and forward to Operations Supervisor. 

4.4.2.2 Terminal Radar Approach Control/Tower. 

A) The TRACON/Tower Watch Supervisor/CIC, upon receipt of volcanic 

information from the ARTCC, will: 

• Ensure NOTAM and PIREP information is disseminated to controllers 

on duty in a timely manner. 

• Ensure PIREP are solicited by controllers. 

• Forward PIREP to ARTCC CWSU/Weather Coordinator or AFSS/FSS 

for dissemination. 

 B) TRACON/Tower controllers are to: 

• Provide SIGMET, CWA, PIREP concerning the ash cloud position, 

altitude and movement to flight crews. 

• Suggest headings and re-routes around known ash or possible ash areas. 

• Assist VFR aircraft to the extent possible in avoiding ash cloud areas. 

• Solicit PIREP and forward to Watch Supervisor. 

4.4.2.3 Automated Flight Service Station/Flight Service Station 

A) The AFSS/FSS Watch Supervisor/Designated Lead Specialist (DLS), upon 

receipt of volcanic information and PIREPs from an ARTCC or a 

TRACON/Tower will ensure: 

• NOTAM and PIREP information is disseminated to specialists on duty in 

a timely manner. 

• PIREPS are solicited by specialists at the Inflight, Flight Watch, and Preflight positions. 

• National dissemination of PIREPS (UA and UUA) using existing 

platforms. 
 

4-9 

B) The AFSS/FSS Watch Supervisor/DLS, upon receipt of volcanic activity or 

an ash cloud PIREP from an aircraft will: 

• Ensure that the PIREP information is forwarded to the ARTCC 

Operations Manager. 

C) AFSS/FSS specialist will: 

• Provide the most current information available (SIGMET, CWA, PIREP, 

NOTAM) concerning volcanic activity/ash cloud position, altitude and 

movement in preflight/inflight briefings. 

• Solicit PIREPS and input PIREP information into existing platforms for 

dissemination. 

• Broadcast Volcanic Ash SIGMETs, CWAs and PIREPS using the 

Hazardous Inflight Weather Advisory Service, Tactical Information 

Broadcast System, and Inflight Broadcast procedures. 

• Pass PIREP information received from aircraft on volcanic activity or ash 

clouds to the AFSS Watch Supervisor. 

4.4.2.4 Air Traffic Control System Command Center (ATCSCC). 

The ATCSCC is the focal point in the National Airspace System for 

providing guidance and direction on how best to manage traffic volume and 

traffic flows that are impacted by constraints. Upon receipt of VAA from the 

Washington or Anchorage VAAC, the ATCSCC relays the advisory to 

designated recipients (Traffic Management Units, airline customers, general 

aviation customers, military coordinators etc.) through e-mail distribution 

and also displays the advisory on the ATCSCC Web site in the advisories 

database: http://www.fly.faa.gov/adv/advADB.jsp
 

4-10 
 

5-1 

Chapter 5 

Observation and Message Report Formats 

5.0 General. This section provides examples, current as of the date of this plan, of 

observations, forecasts, and products which contain volcanic ash or volcanic activity information 

in support of aviation. The basic definitions of these were provided in Chapter 2. Refer to 

official agency or international documents for further information. Volcanic ash wording is 

highlighted in gray. 

5.1 Area Forecast (FA). FA are issued for the CONUS, Alaska, and Hawaii. FA are issued 

three times a day in the CONUS and four (4) times a day in Alaska and Hawaii, and amended as 

necessary. The forecast valid period for the CONUS and Hawaii is 12 hours with an outlook 

period from 12 to 18 hours. In Alaska, the FA is valid for 12 hours and the outlook is valid from 

12 to 30 hours. Example FA are shown for CONUS, Hawaii, and Alaska: 

CONUS FA Example

FAUS46 KKCI 281804 

FA6W 

SFOC FA 281804 AMD 

SYNOPSIS AND VFR CLDS/WX 

SYNOPSIS VALID UNTIL 290500 

CLDS/WX VALID UNTIL 282300...OTLK VALID 282300-290500 

WA OR CA AND CSTL WTRS 

. 

SEE AIRMET SIERRA FOR IFR CONDS AND MTN OBSCN. 

TS IMPLY SEV OR GTR TURB SEV ICE LLWS AND IFR CONDS. 

NON MSL HGTS DENOTED BY AGL OR CIG. 

. 

SYNOPSIS...MT ST HELENS ERUPTED AT 1230 UTC. SEE LATEST SIGMET BRAVO SERIES 

FOR DETAILS. OTRW ALF..11Z RDG OVR GREAT BASIN TO SRN CA. TROF OVR GULF OF 

AK. LGT SW FLOW WA THRU NRN CA WITH LGT AND VRBL WNDS SRN CA. BY 05Z TROF 

MOVG SEWD TO CSTL WTRS OF WA THRU NRN CA WITH RDG OVR 

UT/WRN AZ. MOD SW FLOW WA/OR. SFC..WK TROF CNTRL WA THRU SW ORE 

WITH WK TROF INTR CA. HIGH PRES OVR NRN PAC CSTL WTRS. AMS STBL 

AND DRY EXC FOR CSTL STRATUS. BY 05Z CDFNT DVLPG NERN WA THRU S 

CNTRL ORE WITH GUSTY WLY LOW LVL WNDS OVR WA. 

. 

WA CASCDS WWD ...UPDT 

CASCDS...SKC. SRN PTN VIS 3SM VA. OTLK...MVFR VA. 

CSTLN...BKN-OVC010 TOP 015. VIS 3-5SM BR. 20Z SCT010. 

OTLK...MVFR CIG. 

INLAND...SCT010. VIS 3-5SM BR. 18Z SKC. OTLK...VFR. 

. 

WA E OF CASCDS 

SKC. NRN PTN OCNL VIS 3-5SM VA. OTLK...VFR. 

Alaska FA Example

FAAK58 PAWU 071953 

FA8W 
 

5-2 

ANCC FA 071945 

AK SRN HLF EXCP SE AK... 

. 

AIRMETS VALID UNTIL 080200 

TS IMPLY PSBL SEV OR GREATER TURB SEV ICE LLWS AND IFR CONDS. 

NON MSL HEIGHTS NOTED BY AGL OR CIG. 

. 

UNIMAK PASS TO ADAK AJ...VALID UNTIL 080800 

...CLOUDS/WX... 

***SIGMET***INDIA 1 VALID 071813/080013 

ANCHORAGE FIR. 

VOLCANIC ASH FROM CLEVELAND VOLCANO (N5250 W16957) POSSIBLE ERUPTION OF 

CLEVELAND VOLCANO AT 071000 UTC. ASH BOUNDED BY N5400W16500 - N5330W16200 – 

N5230W16300 – N5300W16600 – N5400W16500. ASH TOPS AT FL150. ASH MOV ESE 40 

KT. ASH VISIBLE IN STLT IMAGERY. 

***AIRMET TURB/LLWS***MOD TURB BLW 120. OCNL MOD TURB FL290-FL370. 

LLWS POTENTIAL DUE TO STG LOW LVL WINDS. NC... 

***AIRMET MT OBSC***MTS OCNL OBSC IN CLOUDS AND PCPN. NC... OTRW 

SCT020 BKN-SCT060 BKN-SCT100 TOPS 120. OCNL BKN020. WDLY SCT 

VIS 5SM -SHRA. SFC WIND W 20G30 KTS. 

OTLK VALID 080800-090200 MVFR CIG SHRA WIND. 

...TURB... 

***AIRMET TURB***OCNL MOD TURB BLW 040. NC... 

...ICE AND FZLVL... 

NIL SIG. FZLVL 030. 

Hawaii FA Example

FAHW31 PHFO 281530 

FA0HI 

HNLC FA 281540 

SYNOPSIS AND VFR CLD/WX 

SYNOPSIS VALID UNTIL 291000 

CLD/WX VALID UNTIL 290400...OUTLOOK VALID 290400-291000 

. 

SEE AIRMET SIERRA FOR IFR CLD AND MT OBSC. 

TS IMPLY SEV OR GREATER TURB SEV ICE LOW LEVEL WS AND IFR COND. 

NON MSL HGT DENOTED BY AGL OR CIG. 

. 

SYNOPSIS...KILAEUA VOLCANO ERUPTED AT 1350 UTC PRODUCING A SMALL AMOUNT OF 

ASH. SEE NOVEMBER SIGMET SERIES FOR DETAILS. A SURFACE TROUGH HAS MOVED 

WEST OF THE ISLANDS...AND TRADE WINDS WILL GRADUALLY STRENGTHEN IN THE 

OFFSHORE WATERS THROUGH THE EARLY PART OF THE WEEK. 

. 

BIG ISLAND MT. 

SCT050 TEMPO BKN050 TOPS 120 ISOL BKN030 LCL VIS 6SM VA. 21Z 

SCT040 BKN-OVC050 TOPS 150 TEMPO BKN030 -SHRA ISOL VIS 1-2SM -SHRA 

BR. OUTLOOK...MVFR CIG SHRA. 

. 

BIG ISLAND LOWER SLOPES...COAST...AND ADJ WATERS. 

SCT050 TEMPO SCT025 BKN040 TOPS 080 -SHRA ISOL BKN030 VIS 5SM -SHRA 

BR. 21Z SCT025 SCT-BKN050 TOPS 100 TEMPO BKN020 -SHRA ISOL BKN015 

VIS 2-3SM -SHRA BR. OUTLOOK...VFR. 

. 
 

5-3 

REST OF AREA. 

SCT050 ISOL BKN040 TOPS 060 -SHRA. OUTLOOK...VFR. 

5.2 Aviation Routine Weather Report (METAR) and Aviation Special Weather Report 

(SPECI). 

METAR Example 

METAR PANC 182150 010006KT 6SM VA FEW040 FEW100 SCT250 02/M09 RMK AO2 SLP 996 

T00171089 

METAR KPDX 271955Z 31010KT 10SM CLR 30/12 A2990 RMK AO2 SLP124 MT ST 

HELENS VOLCANO 50 MILES NNE ERUPTED 271915 SMALL ASH CLOUD EXTENDING 

TO APRX 15000 FEET MOVING E T03000122 

METAR PGUA 241355Z 29005KT 7SM VA SCT020 SCT100 BKN250 26/26 A2981 

 RMK SLP084 

SPECI Example

SPECI KPDX 271926Z 32005KT 10SM CLR 29/13 A2991 RMK AO2 MT ST HELENS 

VOLCANO 50 MILES NNE ERUPTED 271915 SMALL ASH CLOUD EXTENDING TO 

APRX 15000 FEET MOVING E 

5.3 Center Weather Advisories (CWA). An aviation weather warning for conditions which 

either meet or approach national inflight advisory criteria, or will adversely impact the safe flow 

of air traffic within the ARTCC area of responsibility. 

Center Weather Advisory Example

ZAN1 UCWA 210025 

ZAN UCWA 101 VALID UNTIL 210225 

COOK INLET 

POSSIBLE ERUPTION OF MT. AUGUSTINE AT 21/0025 UTC. ASH TOPS ESTIMATED TO 

FL350 BASED ON GROUND OBSERVER REPORT. ASH MOVG NE AT 35 KTS. A SIGMET WILL 

BE ISSUED SHORTLY. 

JO AUG 05 

5.4 Meteorological Impact Statement (MIS). A MIS is an unscheduled flow control and flight 

operations planning forecast. It is a forecast and briefing product produced by the CWSU for 

personnel at ARTCC, ATCSCC, TRACON, and ATCT responsible for making flow control-type 

decisions. The MIS is valid up to 12 hours after issuance time, detailing weather conditions 

expected to adversely impact air traffic flow in the CWSU area of responsibility. This includes 

being valid immediately for existing conditions when CWSU operations begin, or for rapidly 

deteriorating conditions, or being valid up to two hours in advance of expected conditions. A 

MIS may be tailored to meet the unique requirements of the host ARTCC. 

MIS Example

ZAN MIS 01 VALID 092200-100900 

...FOR ATC PLANNING PURPOSES ONLY... 
 

5-4 

GUSTY SE WINDS WILL RESUSPEND VA CAUSING VSBY TO LOWER TO BLW 1 

MILE. CONDS TO IMPV AFT 06Z. 

5.5 Pilot Report (PIREP). Pilots can report the occurrence of volcanic ash in a PIREP as an 

Urgent PIREP (UAA). 

Urgent PIREP Examples

PGSN UUA /OV SN355070/TM 2315/FLDURC/TP B757/RM TOP OF ASH CLOUD 

 OVER ANATAHAN VOLCANO APPROXIMATELY 15000 FT DRIFTING 

 EAST 

OLM UUA /OV CLS /TM 1850 /FL 090 /TP BE35 /WV 31005KT /TB NEG /RM 

MT ST HELENS PLUME TO SE AT 090 

PDX UUA /OV BTG020040/TM 1917/FL085/TP C210/RM ASH CLOUD 115 TO 

 SFC 

CDB UUA /OV VENIAMINOF VOLCANO (5610N 15923W)/TM 2231/FLUNKN/TP 

SF34/RM PUFFS OF SMOKE 1000 FT ABV RIM OR APPROX FL092 (ZAN) 

5.6 SIGMET (WV). WV are brief descriptions of the occurrence and/or expected occurrence of 

specified en-route weather phenomena (e.g., volcanic ash) which may affect the safety of all 

aircraft operations. 

SIGMET Example (over land) 

(SIGMETs issued for the CONUS use VORs not latitude longitude as prescribed in Annex 3) 

WVUS06 KKCI 021430 

SFON WS 021430 

SIGMET NOVEMBER 2 VALID UNTIL 021830 

WA OR 

FROM 50S SEA TO 40WSW YKM TO 40E PDX TO PDX TO 50S SEA 

VA FROM ST HELENS OBS 1040Z AND FCST BLW 140 MOV SE 5KT 

CONDS ENDG 1830Z. 

WVUS06 KKCI 090350 

SFOY WS 090350 

SIGMET YANKEE 4 VALID UNTIL 090750 

WA 

FROM 40WSW GEG TO 30NNE PDT TO 30NNE PDX TO 50S SEA TO 40WSW GEG 

VA ERUPTION ST HELENS OBS AT 0350Z AND FCST BLW FL360 MOV ENE 40KT. 

CONDS CONTG BYD 0750Z. 

SIGMET Example (over Oceanic FIR)

WVNT13 KKCI 251500 

TJZS SIGMET MIKE 5 VALID 251500/252100 KKCISAN JUAN FIR VA FROM SOUFRIERE HILLS LOC N1643 W06211. VA CLD OBS AND 

FCST BLW FL090 WI 15 NM EITHER SIDE LINE N1644 W06420 – N1641 W6300 MOV W 

20KT. NC OTLK 260300Z VA CLD BLW 090 WI 15 NM EITHER SIDE LN N1657 W06445 - 

N1657 W06350 - N1643 W06216. 
 

5-5 

SIGMET Example (from Meteorological Watch Office, Honolulu, HI)

WVPA06 PHFO 282046 

WSVPAS 

KZOA SIGMET SIERRA 452 VALID 282050/290250 PHFOOAKLAND OCEANIC FIR. VOLCANIC ASH FROM ANATAHAN VOLCANO OBS BY 

SATELLITE AT 282002Z SFC/150 WITHIN AREA BOUNDED BY N1644 E14641 - 

N1615 E14644 - N1618 E14544 - N1621 E14543 - N1644 E14641 MOVING E 15 

KNOTS. FCST 290200Z VA CLD APRX SFC/150 WITHIN AREA BOUNDED BY N1621 

E14543 - N1549 E14645 - N1525 E14637 - N1621 E1454. OTLK 290800Z VA 

CLD APRX SFC/FL N1620 E14541 - N1518 E14647 - N1457 E14634 - N1620 

E1454. ANATAHAN VOLCANO LOCATED AT N1621 E14540. 

SIGMET Example (from Meteorological Watch Office, Anchorage, AK)

WVANCI WS 071813 

PAZA SIGMET INDIA 1 VALID 071813/080013 

ANCHORAGE FIR. 

VOLCANIC ASH FROM CLEVELAND VOLCANO (N5250 W16957) POSSIBLE ERUPTION OF 

CLEVELAND VOLCANO AT 071000 UTC. ASH BOUNDED BY N5400W16500 - N5330W16200 – 

N5230W16300 – N5300W16600 – N5400W16500. ASH TOPS AT FL150. ASH MOV ESE 40 

KT. ASH VISIBLE IN STLT IMAGERY. 

ERW OCT 05 

5.7 Terminal Aerodrome Forecasts (TAF). A TAF is the expected meteorological conditions 

significant to aviation at an airport (terminal) for a specified time period, usually 24 hours. The 

U.S. definition of a terminal is the area within five (5) statute miles of the center of an airport's 

runway complex. TAFs are covered in the National Weather Service Instruction (NWSI) 10-

813, Terminal Aerodrome Forecasts. 

TAF Example

TAF PAHO 171738Z 171818 04006KT P6SM SCT100 

 FM0000 35003KT 6SM VA SCT100 BKN250 

 FM1400 00000KT P6SM BKN100 

5.8 Volcanic Ash Advisory (VAA). The VAA is a text message that identifies the volcano, 

time of eruption, and observed and forecast position of the ash and ash cloud. Examples from 

the Washington and Anchorage VAACs are provided. In addition, a “Quick” VAA is an 

advisory stating that the VAAC has received information on the possible eruption of a particular 

volcano. The VAAC will gather further information and a more detailed and full VAA will be 

provided as soon as possible. An example of the “Quick” VAA is also provided. 

 

VAA Example (Washington VAAC)

FVXX21 KNES 251440 

VA ADVISORY 

DTG: 20070825/1440Z VAAC: WASHINGTON 

VOLCANO: ST. HELENS 1201-05 
 

5-6 

PSN: N4612 W12211 AREA: US-WASHINGTON 

SUMMIT ELEV: 8363 FT (2549 M) 

ADVISORY NR: 2005/018 

INFO SOURCE: GOES-10 USGS JRO CAMERA 

AFWA PORTLAND WFO 

ERUPTION DETAILS: RESUSPENDED ASH 

OBS VA DTG: 25/1415Z 

OBS VA CLD: SFC/FL080 10NM WID LINE BTN 

N4635 W12310 - N4612 W12211 MOV NW 10KT 

FCST VA CLD +6HR: 25/2030Z SFC/FL080 N4632 W12243 

- N4619 W12204 - N4613 W12201 - N4610 W12210 - 

N4623 W12252 - N4632 W12243 

FCST VA CLD +12HR: 26/0230Z SFC/FL080 NO VA EXP 

FCST VA CLD +18HR: 26/0830Z NO VA EXP 

RMK: MSH CAMERA AND G-10 VISIBLE IMAGERY SHOW 

A MODERATELY DENSE PLUME OF VA NW OF THE 

VOLCANO ABOUT 30 NM. THIS IS NOT RELATED TO ANY 

ERUPTION BUT IS DUE TO WINDS AT THE CRATER 

RESUSPENDING ASH AND BLOWING IT NW. PLUME HEIGHT 

DOES NOT EXCEED THE CRATER RIM. ...GALLINA 

NXT ADVISORY: 20070825/2045Z 

VAA Example (Anchorage VAAC)

FVAK21 PAWU 071841 

VA ADVISORY 

DTG: 20051007/1840Z VAAC: ANCHORAGE 

VOLCANO: CLEVELAND 1101-24 

PSN: N5250 W16957 AREA: ALEUTIAN ISLANDS ALASKA 

SUMMIT ELEV: 5674 FT (1730 M) 

ADVISORY NR: 2005/001 

INFO SOURCE: AVO 

AVIATION COLOR CODE: ORANGE 

ERUPTION DETAILS: BRIEF ERUPTION FROM 07/1000Z TO 07/1100Z 

OBS VA DTG: 07/1800Z 
 

5-7 

OBS VA CLD: SFC/FL150 N5400 W16500 - N5530 W16200 - N5230 W16300 - N5300 

W16600 - N5400 W16500. MOV SE AT 40KT 

FCST VA CLD +6HR: 08/0000Z SFC/FL150 N5330 W15800 - N5300 W15530 - N513000 

W15600 - N5200 W15900 - N5330 W15800 

FCST VA CLD +12HR: 08/0600Z SFC/FL150 N5300 W15100 - N5200 W14830 - N5030 

W15000 - N5130 W15200 - N5300 W15100 

FCST VA CLD +18HR: 08/1200Z SFC/FL150 NO ASH EXP 

RMK: NONE. ...NAME 

NXT ADVISORY: WILL BE ISSUED BY 2005OCT08/0040Z 

“Quick” VAA Example (Washington VAAC)

FVXX20 KNES 161400 

VA ADVISORY 

DTG: 20060316/1400Z VAAC: WASHINGTON 

VOLCANO: SANTA MARIA 

PSN: N1445 W09133 AREA: GUATEMALA 

SUMMIT ELEV: 12375 FT (3772 M) 

ADVISORY NR: 2006/050 

INFORMATION SOURCE: NOT AVBL 

ERUPTION DETAILS: NOT AVBL 

REMARKS: WE HAVE RECEIVED INFORMATION SUGGESTING A 

POSSIBLE VA EMISSION. WE WILL GATHER FURTHER 

INFORMATION AND ISSUE A FULL ADVISORY AS SOON AS 

POSSIBLE. 

NXT ADVISORY: AS SOON AS POSSIBLE 

5.9 Volcanic Ash Graphic (VAG). The VAG (Figure 5-1) is a graphical description of the text 

Volcanic Ash Advisory (VAA). The VAG can either by a single panel product or a 4 panel 

product (separate panel for each time step t+0, t+6, t+12, and t+18 hours). The following is an 

example of a VAG: 
 

5-8 

5.10 Notice to Airmen (NOTAM). The NOTAM examples are provided in order to ensure 

correct formats are followed. 

Increased Seismic Activity NOTAM Example

!FDC xx/xxx (ARTCC id) (state code).. SEISMIC ACTIVITY ADVISORY EFFECTIVE 

IMMEDIATELY UNTIL FURTHER NOTICE FOR (name) VOLCANO, (latitude/longitude), AND THE 

(name) /id/ VORTAC or VOR/DME (number) DEGREE RADIAL AT (distance) NAUTICAL MILES. 

(name) VOLCANO OBSERVATORY HAS REPORTED INCREASED SEISMIC ACTIVITY IN THE 

VICINITY OF (name) VOLCANO WHICH INDICATES THE POSSIBILITY OF A VOLCANIC 

ERUPTION. AIRCRAFT SHOULD REMAIN ALERT FOR POSSIBLE ERUPTIONS, STEAM, OR 

ASH CLOUDS AND REPORT ANY SIGHTINGS TO ATC IMMEDIATELY. AVIATION ALERT 

Figure 5-1. Volcanic Ash Graphic 

VOLCANIC ASH ADVISORY 

ISSUED: 2006FEB10/1230Z 

VAAC: WASHINGTON 

VOLCANO: SOUFRIERE HILLS 1600-05 

LOCATION: N1642 W06210 

AREA: W INDIES

SUMMIT ELEVATION: 3002FT /915 M 

ADVISORY NUMBER: 2006/025 

INFORMATION SOURCE: PIARCO MWO. GOES12. GFS MODEL WINDS. AWC. 

ERUPTION DETAILS: NEW ERUPTION AROUND 

10/0900Z WITH ONGOING EMISSION

REMARKS: A NEW ERUPTION AT SOUFRIERE 

HILLS BEGAN AROUND 10/0900Z WITH ASH 

ESTIMATED TO FL090 MOVING SOUTHWEST. 

ONGOING ASH EMISSIONS CONTINUE TO 

MOVE TOWARDS THE WEST NORTHWEST 

TO NEAR FL150. 

NEXT ADVISORY: WILL BE ISSUED BY 

2006FEB10/1830Z
 

5-9 

COLOR CODE (orange or red) IS IN EFFECT. CONTACT (name) ARTCC, (telephone number), FOR 

ADDITIONAL INFORMATION. 

FDC 4 CFR section 91.137(a)(1) Flight Restriction NOTAM Format

!FDC xx/xxx (ARTCC id) (state code).. FLIGHT RESTRICTIONS (location:town/city) EFFECTIVE 

(immediately or yyyy-mm-dd-hhhh) UTC UNTIL (further notice or yyyy-mm-dd-hhhh) UTC. 

PURSUANT TO 14 CFR SECTION 91.137(a)(1) TEMPORARY FLIGHT RESTRICTIONS ARE IN 

EFFECT FOR VOLCANIC ERUPTION/ACTIVITY. ONLY RELIEF AIRCRAFT OPERATIONS 

UNDER THE DIRECTION OF (agency in charge) ARE AUTHORIZED IN THE AIRSPACE AT AND 

BELOW ______ FEET (AGL or MSL) WITHIN A ______ STATUTE/NAUTICAL MILE RADIUS OF 

(latitude/longitude) AND THE (name of navaid/id) VORTAC (or) VOR/DME _____ DEGREE RADIAL 

AT _____ NAUTICAL MILES. AVIATION ALERT COLOR CODE (orange or red) IS IN EFFECT. 

PILOTS ARE ADVISED TO EXERCISE EXTREME CAUTION WHEN OPERATING NEAR THIS 

RESTRICTED AREA PARTICULARLY WHILE DOWNWIND FROM THE VOLCANO. (Agency 

name, telephone number, and/or frequency) IS IN CHARGE OF THE OPERATION. (Designated ATC 

facility, (phone number) or the Air Traffic Organization (ATO) System Operations Control Center 

(SOSC), 202-267-3333), IS THE FAA COORDINATION FACILITY. 

Volcanic Ash NOTAM Format

!FDC xx/xxx (ARTCC id) (state code) VOLCANIC ADVISORY FOR (name) VOLCANO (state 

code),(latitude/longitude), and the (name) /id/ VORTAC or VOR/DME (number)DEGREE RADIAL AT 

(distance) NAUTICAL MILES EFFECTIVE IMMEDIATELY UNTIL FURTHER NOTICE. (name) 

VOLCANO HAS BEEN IN AN ACTIVE STATE. HAZARDOUS EMISSIONS OF VOLCANIC ASH 

HAVE INTERMITTENTLY COMPLICATED AIR TRAVEL IN THE AREA. ANY IMPACT ON 

AIRCRAFT OPERATIONS IS DESCRIBED IN CURRENT SIGMET, CWA, OR PIREP 

INFORMATION. AIRCRAFT SHOULD REMAIN ALERT FOR POSSIBLE ASH CLOUDS AND 

REPORT ANY SIGHTINGS TO ATC. AIRCRAFT OPERATORS SHOULD CONTINUALLY 

EVALUATE OPERATIONS IN THE AREA AS DEFINDED BY THE SIGMET. AVIATION ALERT 

COLOR CODE (orange or red) IS IN EFFECT. FLIGHT INTO VOLCANIC ASH MAY CAUSE 

ENGINE DAMAGE/FAILURE AND ABRASION DAMAGE TO AIRFRAME AND WINDSHIELD 

SURFACES. ANY AIR CARRIERS, INCLUDING FOREIGN AIR CARRIERS THAT OBSERVE OR 

EXPERIENCE ANY DIFFICULTIES RESULTING FROM AN ENCOUNTER WITH VOLCANIC 

ASH, PLEASE NOTIFY ATC IMMEDIATELY IN ACCORDANCE WITH FAR 121.561 AND 

ICAO,ANNEX 3, PARAGRAPH 5.4 (SPECIAL AIRCRAFT OPERATIONS), AND ANNEX 6 

PARAGRAPH 4.4.3 (HAZARDOUS FLIGHT CONDITIONS). CONTACT (name) ARTCC, (phone 

number), FOR ADDITIONAL INFORMATION. 

5.11 USGS Volcanic Observatory Notice for Aviation (VONA). Suggested format for a 

VONA, which is issued by a VO when a color code changes (up or down) or within a color-code 

level when an ash-producing event or other significant change in volcanic behavior occurs. 

(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION

(2) Issued: Universal (Z) date and time (YYYYMMDD/HHMMZ). 

(3) Volcano: Name and number (per Smithsonian database at 
 

5-10 

 http://www.volcano.si.edu/world/ ) 

(4) Current Aviation Color Code: 

(5) Previous Aviation Color Code: 

(6) Source: Name of Volcano Observatory (volcanological agency) 

(7) Notice Number: Unique number with year 

(8) Volcano Location: Latitude, longitude (in NOTAM format) 

(9) Area: Regional descriptor (e.g., Cook Inlet, Alaska, USA) 

(10) Summit Elevation: nnnn M (nnnn FT) 

(11) Volcanic Activity Summary: 

Concise statement that describes activity at the volcano. 

 If known, specify time of onset and duration of eruptive activity.

(12) Volcanic Cloud Height: 

Best estimate of ash-cloud top in nnnn M (nnnnn FT) above 

summit or AMSL (specify which). Give source of height data 

(ground observer, pilot report, radar, etc.). “NIL” if no ash cloud 

is produced. 

(13) Other Volcanic Cloud information: 

Brief summary of relevant cloud characteristics such as color of 

cloud, shape of cloud, direction of movement, etc. Specify if cloud 

height is obscured or suspected to be higher than what can be 

observed clearly. “NIL” if no ash cloud produced. 

(14) Remarks: Optional. Brief comments on related topics such as monitoring 

data, observatory actions, volcano’s previous activity, etc. 

(15) Contacts: Names, phone numbers (voice and fax), email addresses. 

(16) Next Notice: “Will be issued when conditions at the volcano warrant changing 

the aviation color code or when a significant volcanic event occurs 

within the current color code.” Or, indicate if final notice for an 

event. 
 

5-11 

5.12 Volcanic Activity Report (VAR). The VAR form (Figure 5-2) is tentative. It is 

undergoing international review and is expected to be endorsed by the ICAO Council in the first 

quarter of 2007 and become applicable in November 2007. 

Figure 5-2. Volcanic Activity Report (tentative)

A-1 

APPENDIX A 

BACKUP OPERATIONS

1.0 Backup Operations. Backup operations are implemented during periods of outage at 

a facility or when significant operational conditions warrant the need to maintain 

continuity in service during an ongoing event. 

1.1 Backup Services. Backup services are provided for products issued by: 

National Oceanic and Atmospheric Administration’s (NOAA) (National Weather 

Service (NWS) and National Environmental Satellite, Data, and Information 

Service (NESDIS)): 

 Meteorological Watch Offices (MWO) 

 Volcanic Ash Advisory Centers (VAAC) 

 World Area Forecast Center (WAFC) 

USGS: Volcano Observatories 

FAA: U.S. NOTAM Office 

2.0 Backup Procedures for NOAA (NWS and NESDIS). The following describes the 

backup procedures for the MWO, VAAC, and WAFC. 

2.1 MWO 

The NWS has three MWO: Anchorage, Honolulu and Kansas City. Each has a 

separate backup procedure as described in the following section. 

2.1 1 Anchorage MWO 

The Anchorage MWO (Alaska Aviation Weather Unit) SIGMET backup 

is provided by several offices dependent upon flight level. 

High level SIGMETs (FL250 and above) and Volcanic 

Eruptions/SIGMETS will be issued by the Aviation Weather Center 

(AWC). 

Low level SIGMETs (below FL250) will be issued by the Alaska NWS 

forecast offices. 

If the Anchorage MWO cannot issue SIGMETs, the Juneau Forecast 

Office will take responsibility for issuing low level SIGMETs in the 

Juneau FA area. 

The Fairbanks Forecast Office will take responsibility for issuing low 

level SIGMETs in the Fairbanks FA and Anchorage FA areas. 
A-2 

The Alaska FA will not be backed up in a short term (less than 24 hours) 

unplanned backup scenario. If possible, the AFSSs at Kenai, Juneau and 

Fairbanks will be notified of the temporary cancellation of the FA 

production. If notification is not possible, the Juneau Forecast Office will 

notify the Juneau AFSS and have the Fairbanks Forecast Office notify the 

Kenai and Fairbanks AFSS. In a longer than 24 hour backup scenario, 

AAWU forecasters will be sent TDY to the Juneau and Fairbanks FOs as 

soon as possible to assume AAWU SIGMET, AIRMET and FA 

production. 

2.1.2 Honolulu MWO 

When the Honolulu MWO is down and cannot produce or distribute their 

products, the AWC will provide backup for MWO-related products 

(SIGMETs, AIRMETs, Area Forecasts) and WFO Monterey will provide 

backup for WFO related products (TAFs, public advisories). 

The Lead Forecaster or MIC at Honolulu will notify AWC and WFO 

Monterey in the event that backup services are required. 

2.1.3 Kansas City MWO/AWC 

In the event that Kansas City MWO/AWC is down and unable to produce 

or distribute products, the following offices will provide backup services. 

SIGMETs issued for Oceanic Flight Information Regions 

 Atlantic (KZNY FIR) – Tropical Prediction Center (TPC) 

 Pacific (KZOA FIR) – WFO Honolulu 

 Other (KJZS, KZHU, KZMA FIRs) – TPC 

CONUS SIGMETs 

 AFWA 

Area Forecasts 

 Atlantic, Carribean, Gulf of Mexico – TPC 

 Pacific – WFO Honolulu 

2.2 VAAC 

2.2.1 Anchorage VAAC

 
A-3 

If the Anchorage VAAC cannot issue a Volcanic Ash Advisory or the 

associate Volcanic Ash Graphic, responsibility will be transferred to the 

Washington VAAC. 

2.2.2 Washington VAAC 

Backup for the Washington VAAC is provided by the Air Force Weather 

Agency (AFWA) at Offutt Air Force Base in Omaha, Nebraska. AFWA 

will be notified by the Washington VAAC of the need for backup and 

requested to initiate any required backup operations. The following 

actions are taken by AFWA: 

 

 Issues a message under an FVXX## header, stating that the 

Washington VAAC is out of operation, and that AFWA is assuming 

the role of the Washington VAAC until further notice. 

 Monitors volcanoes by satellite, and receives relevant PIREPs, 

SIGMETs, etc. 

 If the Washington VAAC is down and cannot produce or distribute 

their products, AFWA will provide backup for products and 

dissemination. Required products and format are as follows: 

3⁄4 Volcanic Ash Advisory (VAA) – (FVXX20-27 KNES) 

3⁄4 Graphical products VAFTAD – 12, 24 hr page 1 (PHBE10 

KWBC) 

3⁄4 Graphical product VAFTAD - 36, 48 hr page 2 (PHBI 10 

KWBC) 

 Provides information by phone to AWC, ATCSCC, Anchorage VAAC 

and any other pertinent U.S. agency. 

 VAAs are issued on an as-needed basis. Graphical products are issued 

if ash plume is expected to last at least 24 hrs. 

 Timeliness: Products are available as soon as possible after creation. 

 Notify responsible MWOs in Washington-VAAC’s Area of 

Responsibility to ensure initiation of SIGMETS advisories; notify 

government agencies (i.e. FAA, AWC, FEMA, etc) as required, of 

VAA issuance. 

Washington VAAC will notify AFWA as to termination of backup 

support. The Washington VAAC is responsible for issuing notice of its 

return to operations, which includes date and time operations are taken 

over by the Washington VAAC. 

 

The SAB lead analyst is the operational point of contact at the Washington 

VAAC. The AFWA METSAT Applications Weather Flight duty analyst is 

the operational point of contact at AFWA. 

2.3 WAFC 

 
A-4 

2.3.1 SIGWX charts provided by the Washington WAFC will be backed 

up by the London WAFC. 

3.0 Backup Procedures for USGS. The backup for all USGS Volcano Observatories is 

the Alaska Volcano Observatory in Anchorage Alaska. In the event that the Alaska 

Volcano Observatory cannot serve as a backup, the Cascades Volcano Observatory will 

provide that function. 

4.0 Backup Procedures for FAA. U.S. NOTAM Office. The National Notice to Airman 

Office is located at the ATCSCC in Herndon, Virginia. In an event requiring backup 

operations, a contingent of NOTAM staff personnel will relocate to the Washington Air 

Route Traffic Control Center, located in Leesburg, Virginia and re-establish operations.
B-1 

APPENDIX B 

TRANSPORT AND DISPERSION MODELS 

B.1 HYSPLIT 

The HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory) model 

is configured to run volcanic ash simulations operationally at NOAA NCEP in support of 

the Washington and the Anchorage VAAC. Input forecast meteorology can be from 

either the Global Forecast System (GFS) or the North American Mesoscale (NAM) 

model. Ash particle sizes range from 0.3 to 30 microns. Particles are assumed to be 

evenly distributed within the eruption column from the volcano summit to the column 

top. Since the amount of ash emitted is not known at the time the forecast is run, a unit 

source is assumed. Graphical model output in “VAFTAD format” (shown below, 

Volcanic Ash Forecast Transport and Dispersion model) is distributed over the World 

Area Forecast System and is available at http://weather.noaa.gov/fax/wafsash.shtml. The 

graphical output depicts forecast areas of “visual ash”. The model visual ash boundary is 

based on a correlation between historical model output and satellite analysis, and further 

refined when the VAAC chooses, as the visual ash boundary, a model concentration 

contour that best depicts the forecast based on the observed ash area. The Volcanic Ash 

Graphic (VAG, see Sec. 4.1.2.1 and 5.10) issued by the VAAC may be based on 

HYSPLIT model output. 

A description of the complete HYSPLIT modeling system is given at 

http://www.arl.noaa.gov/ready/hysplit4.html. The system is used to compute 

atmospheric transport from simple air parcel trajectories to complex dispersion and 

deposition simulations. Input meteorological data is in a format unique to HYSPLIT and 

programs to convert various meteorological models’ output to the HYSPLIT-format are 

included in the system. The dispersion of a substance is calculated by assuming puff 

and/or particle dispersion. The transport can occur forward or backward in time. 

Backward simulations can be used to estimate the source region of observed volcanic ash 

or other substance. Dispersion ensembles can calculate concentration probability output. 

Users may specify source starting height(s), source particle size and density, deposition 

removal constants, output levels, etc. Plotting programs generate postscript files. 

Dispersion/deposition output can be converted to WMO gridded binary format. 

For planning or training, HYSPLIT can be run interactively on the Web or the 

code executable and meteorological data can be downloaded to a Windows PC at web 

site: http://www.arl.noaa.gov/ready/hysplit4.html. The HYSPLIT volcanic ash web page 

is http://www.arl.noaa.gov/ready/ash.html. 
B-2 

Figure 1. HYSPLIT model output (VAFTAD format) for an eruption of Mt. Augustine on 

January 14, 2006. Plots on the left have a valid time of 1300 UTC January 14; plots on 

the right 0100 UTC January 15. Plots are for the layers surface-FL550 (bottom), 

surface-FL200, FL200-FL350, and FL350-FL550 (top).
B-3 

B.2 Puff 

Puff * is a volcanic ash dispersion model that tracks particles through a 

Lagrangian formulation of advection combined with fallout and turbulent diffusion using 

a random-walk technique. During the simulation, the model treats the emitted particles 

as a sequence of packets or puffs over a length of time represented by the eruption 

duration. The range of particle size, initial plume shape, and fall dynamics can be 

selected by the user, with both variable and default input parameters available. The 

default ash particle size range is 1 to 100 microns. Particles are distributed within the 

eruption column from the volcano summit to the column top, and the number of particles 

associated with a model run is configured to be directly proportional to the eruption 

duration set by the analyst. The graphics output depicts ash plumes as tracer particles 

color-coded by height, or as relative concentration. Output can be displayed in both static 

and animated graphics. A description of the Puff model is given at 

http://puff.images.alaska.edu/index.shtml. This site also hosts a web version of the 

model. 

Puff is run operationally at the AFWA in support of DOD operations worldwide. 

It is also used at the Anchorage and Washington VAAC as well as the Alaska Volcano 

Observatory for single eruptions. The AFWA version of Puff has the ability to ingest 

meteorological wind field data from the Global Forecast System. The AFWA Graphical 

User Interface allows for variations of model capabilities including depicting dispersion 

of an existing ash cloud, and both continuous and multiple eruptions. In the AFWA 

version users also have the ability to input an existing ash cloud by outlining a satellite 

image. A Digital Elevation Model is also used to improve forecasting of low level 

transport and surface deposition. The Puff graphic visual boundary is verified using 

satellite analysis, and further refined when necessary. Both static and animated graphical 

output for global volcanic eruptions as well as hypothetical simulations are available at 

https://weather.afwa.af.mil/environmental_events.html. During backup of the 

Washington VAAC, the Puff model graphic output is converted into a VAFTAD format 

for distribution over the World Area Forecast System. 

 

* Puff (not an acronym) was developed by the University of Alaska, Fairbanks. 
B-4 
C-1 

APPENDIX C 

ACRONYMS and TERMS 

AAWU: The Alaska Aviation Weather Unit (also known as the Anchorage MWO). 

ACC: Area Control Center. A unit established to provide air traffic control service to 

controlled flights in control areas under its jurisdiction, also referred to as the Air Route 

Traffic Control Center (ARTCC). 

AFSS: Automated Flight Service Station. 

AFWA: Air Force Weather Agency. 

AIREP: Aircraft Report. A report from an aircraft in flight prepared in conformity with 

requirements for position, and operational and/or meteorological reporting. 

AIRMET: AIRman's METeorological Information. Information issued by a 

meteorological watch office (MWO) concerning the occurrence or expected occurrence 

of specified en route weather phenomena which may affect the safety of aircraft 

operations. 

AOC: Airline Operations Center. A facility under control by an air carrier that 

dispatches aircraft in accordance with existing standards and regulations and monitors 

and controls aircraft en route. 

ARL: Air Resources Laboratory. 

ARTCC: Area Route Traffic Control Center. A unit established to provide air traffic 

control service to controlled flights in control areas under its jurisdiction, also referred to 

as the Area Control Center (ACC). 

ASHTAM: A special series NOTAM advising of volcanic activity, a volcanic eruption 

and/or a volcanic ash cloud that is of significance to aircraft operations. 

ATCSCC: Air Traffic Control System Command Center.

ATCT: Air Traffic Control Tower. 

ATO: Air Traffic Organization.

ATS: Air Traffic System. 

AWC: Aviation Weather Center. 

CIC: Controller in charge. 

Color Code: An alert level for aviation use to signify the status of a volcano during 

periods of quiescence, unrest, or eruption. 

CONUS: Continental United States. 

CWA: Center Weather Advisory. The CWA is 0-2 hour (valid up to 2 hours after 

issuance) aviation weather warning for conditions meeting or approaching national inflight advisory (AIRMET, SIGMET, or SIGMET for convection) criteria. 

CWSU: Center Weather Service Unit. Joint FAA/NWS meteorological support units 

composed of NWS meteorologists and FAA Traffic Management Unit (TMU) specialists 

directly supporting FAA’s 21 Air Route Traffic Control Centers (ARTCC). 

DOD: Department of Defense. 

EMO: Emergency Management Office (Saipan).

FA: Area Forecast. A text forecast issued by the 3 U.S. Meteorological Watch Offices 

(MWOs) which describe weather conditions specific to aviation interests. 

FAA: Federal Aviation Administration. 

FDC: Flight Data Center. 
C-2 

FIR: Flight Information Region. Airspace defined dimensions within which flight 

information service and alerting service are provided. 

FL: Flight level. 

FSS: Flight Service Station. 

GAMET: An area forecast in abbreviated plain language for low-level flights in a flight 

information region or sub-area thereof, prepared by a designated meteorological office. 

GMT: Greenwich Mean Time.

HYSPLIT: The HYbrid Single-Particle Lagrangian Integrated Trajectory model. The 

principal model used to forecast the transport and dispersion of the ash cloud. 

IAVW: International Airways Volcano Watch. International arrangements for 

monitoring and providing atmospheric volcanic ash warnings to aircraft. 

ICAO: International Civil Aviation Organization. 

International NOTAM Office: An office designated by a State for the exchange of 

NOTAMs internationally. 

METAR: METeorological Aerodrome Report. An international code (Aviation Routine 

Weather Report) used for reporting, recording and transmitting weather observations. 

Meteorological Authority: The authority providing or arranging for the provision of 

meteorological service for international air navigation on behalf of Contracting States and 

for the provision of meteorological services for national practices. 

MIS: Meteorological Impact Statement. An unscheduled flow control and flight 

operations planning forecast. It is a 2 to 12 hour (valid up to 12 hours after issuance) 

briefing and forecast product at ARTCC, ATCSCC, TRACON, and ATCTs responsible 

for making flow-control type decisions.

MWO: Meteorological Watch Office. A meteorological office designated to provide inflight hazardous weather advisories to AOCs, ATS, and pilots. 

NAS: United States National Airspace System. 

NASA: National Aeronautics and Space Administration. 

NAVAID: Navigational Aid. 

NCEP: National Centers for Environmental Prediction. 

NESDIS: National Environmental Satellite, Data, and Information Service. 

NOAA: National Oceanic and Atmospheric Administration. 

NOTAM: Notice to Airmen. A notice containing information concerning the 

establishment, condition or change in any aeronautical facility, service, procedure or 

hazard, the timely knowledge of which is essential to personnel concerned with flight 

operations. 

NVAOPA: National Volcanic Ash Operations Plan for Aviation. 

NWS: National Weather Service.

PIREP: Pilot Report. A report of in-flight weather by an aircraft pilot or crew member. 

A complete coded report includes the following mandatory information in this order: 

location and/or extent of reported weather phenomenon, time, flight level, and type of 

aircraft. 

SAB: Satellite Analysis Branch. 

SI: Smithsonian Institution. 

SIGMET: SIGnigicant METetorological Advisory. SIGMETs are a brief description of 

the occurrence and/or expected occurrence of specified en-route weather phenomena 

which may affect the safety of all aircraft operations. 
C-3 

SIGWX Chart: Mid- and High-Level Significant Weather Chart. A graphical depiction 

of significant weather for FL100-FL450 (Mid-Level) and FL250-FL630 (High-Level). 

SPECI: In the METAR observation program, a surface observation issued on a nonroutine basis as dictated by changing meteorological conditions.

TAF: Terminal Aerodrome Forecast. A forecast of meteorological conditions significant 

to aviation at an airport location (location within 5 nm of center of the airport’s runway 

complex). 

TMU: Traffic Management Unit.

TRACON: Terminal Radar Approach Control. 

USGS: United States Geological Survey. 

USNOF: U.S. NOTAM Office.

UTC: Coordinated Universal Time. An international time standard most commonly used 

in weather products and observations. Also known as Greenwich Mean Time (GMT). 

VAA: Volcanic Ash Advisory. Information issued by a Volcanic Ash Advisory Center 

concerning the occurrence or expected occurrence of volcanic ash which may affect the 

safety of aircraft operations. 

VAAC: Volcanic Ash Advisory Center. A meteorological office designated to provide 

Volcanic Ash Advisories and Volcanic Ash Graphics. 

VAFTAD: Volcanic Ash Forecast Transport and Dispersion model was used by NCEP 

from 1992 to 2004. When HYSPLIT became operational in 2005, VAFTAD look-alike 

output was created for product continuity. 

VAG: Volcanic Ash Graphic. A graphical depiction of the Volcanic Ash Advisory 

(VAA). 

VONA: Volcano Observatory Notice for Aviation. A short message in structured format 

issued by the USGS Volcanic Observatory to describe volcanic activity to the aviation 

sector, highlighting ash-plume information and including the aviation color-code level. 

VAR: Volcanic Ash Report. A report of volcanic ash similar in format to a PIREP. 

However, the VAR may include additional information on the physical characteristics of 

the ash. 

VO: Volcano Observatory. 

Volcanic Ash: Small fragments (generally less than 2 mm in diameter) of rock, mineral, 

and volcanic glass that are created during explosive eruptions by the shattering of solid 

rocks and violent separation of magma (molten rock) into tiny pieces. The erupted 

material – along with gases released from the decompressing magma – is entrained 

upward in a convecting, columnar mass above the volcano. The larger erupted pieces fall 

out of the column within minutes to hours and are deposited around the volcano, while 

the smaller particles (ash) are spread by winds aloft as a diffuse cloud.

Volcanic Eruption: Ejection of magma, gases, and/or old volcanic rock products at the 

Earth’s surface, either explosively as fragmental material or effusively as liquid lava. 

Not included are energetic but non-ash-bearing steam explosions. 

WA: (see AIRMET)

WFO: Weather Forecast Office. One of 122 National Weather Service offices which 

provide a wide variety of weather forecasts and observations for specific states or 

portions of states. These forecasts include, but are not limited to, public, aviation, 

marine, fire weather, and hydrology. 

WMO: World Meteorological Organization.
C-4 

World Area Forecast Center: A meteorological centre designated to prepare and issue 

significant weather forecasts and upper air forecasts in digital form on a global basis 

direct to States by appropriate means as part of the aeronautical fixed service. 

WV: (see SIGMET) 

 
D-1 

APPENDIX D 

List of U.S. Volcanoes 

U.S. volcanoes showing the responsible USGS Volcano Observatory (VO) and primary Air 

Route Traffic Control Center (ARTCC), Meteorological Watch Office (MWO), and Weather 

Forecast Office (WFO) to be notified by the VO when the aviation color code is raised or 

lowered at a volcano or when a significant change in activity occurs within a color-code level. 

Not all U.S. volcanoes are monitored instrumentally by the USGS. A list of volcanoes taken 

from the Smithsonian Institution's global volcanism database at http://www.volcano.si.edu/. 

Volcanoes are listed alphabetically within states; Number refers to unique ID number used in the 

Smithsonian database. AVO = Alaska Volcano Observatory, CVO = Cascades Volcano 

Observatory, HVO = Hawaiian Volcano Observatory, LVO = Long Valley Observatory, YVO = 

Yellowstone Volcano Observatory. Negative value for elevation indicates depth to top of 

submarine volcano. 

Volcano 

Name State Numb

er 

Latitude 

DDMM 

Longitude 

DDDMM 

Elev. 

feet VO ARTCC MWO WFO 

Adagdak Alaska 

1101-

112 N 5159 W 17636 2001 AVO Anchorage Anchorage Anchorage 

Akutan Alaska 

1101-

32- N 5408 W 16559 4275 AVO Anchorage Anchorage Anchorage 

Amak Alaska 

1101-

39- N 5525 W 16309 1601 AVO Anchorage Anchorage Anchorage 

Amukta Alaska 

1101-

19- N 5230 W 17115 3498 AVO Anchorage Anchorage Anchorage 

Aniakchak Alaska 

1102-

09- N 5653 W 15810 4400 AVO Anchorage Anchorage Anchorage 

Atka 

(Korovin) Alaska 

1101-

16- N 5223 W 17409 5030 AVO Anchorage Anchorage Anchorage 

Augustine Alaska 

1103-

01- N 5922 W 15326 4108 AVO Anchorage Anchorage Anchorage 

Behm CanalRudyerd Bay Alaska 1105-

07- N 5519 W 13103 1641 AVO Anchorage Anchorage Juneau 

Black Peak Alaska 

1102-

08- N 5633 W 15847 3386 AVO Anchorage Anchorage Anchorage 

Bobrof Alaska 

1101-

10- N 5155 W 17726 2421 AVO Anchorage Anchorage Anchorage 

Bogoslof Alaska 

1101-

30- N 5356 W 16802 492 AVO Anchorage Anchorage Anchorage 

Buldir Alaska 

1101-

01- N 5221 E 17555 2152 AVO Anchorage Anchorage Anchorage 

Buzzard 

Creek Alaska 

1105-

001 N 6404 W 14825 2723 AVO Anchorage Anchorage Anchorage 

Carlisle Alaska 

1101-

23- N 5254 W 17003 5315 AVO Anchorage Anchorage Anchorage 

Chagulak Alaska 

1101-

20- N 5235 W 17108 3747 AVO Anchorage Anchorage Anchorage 

Chiginagak Alaska 

1102-

11- N 5708 W 15659 7287 AVO Anchorage Anchorage Anchorage 

Churchill Alaska 

1105-

03- N 6123 W 14425 16421 AVO Anchorage Anchorage Anchorage 
D-2 

Volcano 

Name State Number 

Latitude 

DDMM 

Longitude 

DDDMM 

Elev. 

feet VO ARTCC MWO WFO 

Cleveland Alaska 

1101-

24- N 5250 W 16957 5676 AVO Anchorage Anchorage Anchorage 

Dana Alaska 

1102-

05- N 5538 W 16113 4442 AVO Anchorage Anchorage Anchorage 

Davidof Alaska 

1101-

04- N 5158 E 17820 1076 AVO Anchorage Anchorage Anchorage 

Denison Alaska 

1102-

21- N 5825 W 15427 7504 AVO Anchorage Anchorage Anchorage 

Douglas Alaska 

1102-

27- N 5851 W 15333 7021 AVO Anchorage Anchorage Anchorage 

Duncan 

Canal Alaska 

1105-

05- N 5630 W 13306 49 AVO Anchorage Anchorage Juneau 

Dutton Alaska 

1102-

011 N 5510 W 16216 4941 AVO Anchorage Anchorage Anchorage 

Edgecumbe Alaska 

1105-

04- N 5703 W 13545 3183 AVO Anchorage Anchorage Juneau 

Emmons 

Lake Alaska 

1102-

02- N 5520 W 16205 4712 AVO Anchorage Anchorage Anchorage 

Fisher Alaska 

1101-

35- N 5439 W 16426 3648 AVO Anchorage Anchorage Anchorage 

Fourpeaked Alaska 

1102-

26- N 5846 W 15340 6907 AVO Anchorage Anchorage Anchorage 

Frosty Alaska 

1102-

01- N 5505 W 16249 6601 AVO Anchorage Anchorage Anchorage 

Gareloi Alaska 

1101-

07- N 5147 W 17848 5161 AVO Anchorage Anchorage Anchorage 

Gordon Alaska 

1105-

021 N 6208 W 14305 9039 AVO Anchorage Anchorage Anchorage 

Great Sitkin Alaska 

1101-

12- N 5205 W 17608 5709 AVO Anchorage Anchorage Anchorage 

Griggs Alaska 

1102-

19- N 5821 W 15506 7602 AVO Anchorage Anchorage Anchorage 

Hayes Alaska 

1103-

05- N 6138 W 15225 9955 AVO Anchorage Anchorage Anchorage 

Herbert Alaska 

1101-

22- N 5245 W 17007 4200 AVO Anchorage Anchorage Anchorage 

Iliamna Alaska 

1103-

02- N 6002 W 15305 10017 AVO Anchorage Anchorage Anchorage 

Imuruk Lake Alaska 

1104-

06- N 6536 W 16355 2001 AVO Anchorage Anchorage Fairbanks 

Ingakslugwat 

Hills Alaska 

1104-

05- N 6126 W 16428 623 AVO Anchorage Anchorage Fairbanks 

Isanotski Alaska 

1101-

37- N 5446 W 16343 8025 AVO Anchorage Anchorage Anchorage 

Kagamil Alaska 

1101-

26- N 5258 W 16943 2930 AVO Anchorage Anchorage Anchorage 

Kaguyak Alaska 

1102-

25- N 5836 W 15402 2956 AVO Anchorage Anchorage Anchorage 

Kanaga Alaska 

1101-

11- N 5155 W 17710 4288 AVO Anchorage Anchorage Anchorage 

Kasatochi Alaska 

1101-

13- N 5211 W 17530 1030 AVO Anchorage Anchorage Anchorage 
D-3 

Volcano 

Name State Number 

Latitude 

DDMM 

Longitude 

DDDMM 

Elev. 

feet VO ARTCC MWO WFO 

Katmai Alaska 

1102-

17- N 5817 W 15458 6716 AVO Anchorage Anchorage Anchorage 

Kialagvik Alaska 

1102-

12- N 5712 W 15645 5502 AVO Anchorage Anchorage Anchorage 

Kiska Alaska 

1101-

02- N 5206 E 17736 4003 AVO Anchorage Anchorage Anchorage 

Koniuji Alaska 

1101-

14- N 5213 W 17508 896 AVO Anchorage Anchorage Anchorage 

Kookooligit 

Mountains Alaska 

1104-

03- N 6336 W 17026 2208 AVO Anchorage Anchorage Fairbanks 

Kukak Alaska 

1102-

23- N 5827 W 15421 6703 AVO Anchorage Anchorage Anchorage 

Kupreanof Alaska 

1102-

06- N 5601 W 15948 6217 AVO Anchorage Anchorage Anchorage 

Little Sitkin Alaska 

1101-

05- N 5157 E 17833 3852 AVO Anchorage Anchorage Anchorage 

Mageik Alaska 

1102-

15- N 5812 W 15515 7103 AVO Anchorage Anchorage Anchorage 

Makushin Alaska 

1101-

31- N 5353 W 16655 5906 AVO Anchorage Anchorage Anchorage 

Martin Alaska 

1102-

14- N 5810 W 15522 6113 AVO Anchorage Anchorage Anchorage 

Moffett Alaska 

1101-

111 N 5157 W 17645 3924 AVO Anchorage Anchorage Anchorage 

Novarupta Alaska 

1102-

18- N 5816 W 15509 2759 AVO Anchorage Anchorage Anchorage 

Nunivak 

Island Alaska 

1104-

02- N 6001 W 16620 1677 AVO Anchorage Anchorage Anchorage 

Okmok Alaska 

1101-

29- N 5326 W 16808 3521 AVO Anchorage Anchorage Anchorage 

Pavlof Alaska 

1102-

03- N 5525 W 6602 8265 AVO Anchorage Anchorage Anchorage 

Pavlof Sister Alaska 

1102-

04- N 5527 W 16151 7028 AVO Anchorage Anchorage Anchorage 

Recheschnoi Alaska 

1101-

28- N 5309 W 16832 6510 AVO Anchorage Anchorage Anchorage 

Redoubt Alaska 

1103-

03- N 6029 W 15245 10197 AVO Anchorage Anchorage Anchorage 

Roundtop Alaska 

1101-

38- N 5448 W 16335 6139 AVO Anchorage Anchorage Anchorage 

Sanford Alaska 

1105-

01- N 6213 W 14408 16238 AVO Anchorage Anchorage Anchorage 

Seguam Alaska 

1101-

18- N 5219 W 17231 3458 AVO Anchorage Anchorage Anchorage 

Segula Alaska 

1101-

03- N 5201 E 17808 3806 AVO Anchorage Anchorage Anchorage 

Semisopoch

noi Alaska 

1101-

06- N 5156 E 17935 4006 AVO Anchorage Anchorage Anchorage 

Sergief Alaska 

1101-

15- N 5202 W 17456 1837 AVO Anchorage Anchorage Anchorage 

Shishaldin Alaska 

1101-

36- N 5445 W 16358 9374 AVO Anchorage Anchorage Anchorage 
D-4 

Volcano 

Name State Number 

Latitude 

DDMM 

Longitude 

DDDMM 

Elev. 

feet VO ARTCC MWO WFO 

Snowy 

Mountain Alaska 

1102-

20- N 5820 W 15441 7094 AVO Anchorage Anchorage Anchorage 

Spurr Alaska 

1103-

04- N 6118 W 15215 11070 AVO Anchorage Anchorage Anchorage 

St. Michael Alaska 

1104-

04- N 6327 W 16207 2346 AVO Anchorage Anchorage Fairbanks 

St. Paul 

Island Alaska 

1104-

01- N 5711 W 17018 666 AVO Anchorage Anchorage Anchorage 

Steller Alaska 

1102-

22- N 5826 W 15424 7454 AVO Anchorage Anchorage Anchorage 

Stepovak Alaska 

1102-

051 N 5556 W 16000 5102 AVO Anchorage Anchorage Anchorage 

Table TopWide Bay Alaska 1101-

311 N 5358 W 16641 2599 AVO Anchorage Anchorage Anchorage 

Takawangha Alaska 

1101-

09- N 5152 W 17800 4754 AVO Anchorage Anchorage Anchorage 

Tanaga Alaska 

1101-

08- N 5153 W 17809 5925 AVO Anchorage Anchorage Anchorage 

Tlevak StraitSuemez Is. Alaska 1105-

06- N 5515 

W

6 1348 164 AVO Anchorage Anchorage Juneau 

Trident Alaska 

1102-

16- N 5814 W 15506 6116 AVO Anchorage Anchorage Anchorage 

UgashikPeulik Alaska 1102-

13- N 5745 W 15622 4836 AVO Anchorage Anchorage Anchorage 

Ukinrek 

Maars Alaska 

1102-

131 N 5750 W 15631 299 AVO Anchorage Anchorage Anchorage 

Uliaga Alaska 

1101-

25- N 5304 W 16946 2914 AVO Anchorage Anchorage Anchorage 

Unnamed Alaska 

1102-

132 N 5752 W 15525 984 AVO Anchorage Anchorage Anchorage 

Veniaminof Alaska 

1102-

07- N 5610 W 15923 8225 AVO Anchorage Anchorage Anchorage 

Vsevidof Alaska 

1101-

27- N 5308 W 16842 7051 AVO Anchorage Anchorage Anchorage 

Westdahl Alaska 

1101-

34- N 5431 W 16439 5427 AVO Anchorage Anchorage Anchorage 

Wrangell Alaska 

1105-

02- N 6200 W 14401 14164 AVO Anchorage Anchorage Anchorage 

Yantarni Alaska 

1102-

10- N 5701 W 15711 4413 AVO Anchorage Anchorage Anchorage 

Yunaska Alaska 

1101-

21- N 5239 W 17038 1805 AVO Anchorage Anchorage Anchorage 

Adams Washington 

1201-

04- N 4612 W 12129 12278 CVO Seattle Kansas City Pendleton 

Baker Washington 

1201-

01= N 4847 W 12149 10778 CVO Seattle Kansas City Seattle 

Glacier Peak Washington 

1201-

02- N 4807 W 12107 10542 CVO Seattle Kansas City Seattle 

Indian 

Heaven Washington 

1201-

07- N 4556 W 12149 5925 CVO Seattle Kansas City Pendleton 

Rainier Washington 

1201-

03- N 4652 W 12145 14410 CVO Seattle Kansas City Seattle 
D-5 

Volcano 

Name State Number 

Latitude 

DDMM 

Longitude 

DDDMM 

Elev. 

feet VO ARTCC MWO WFO 

St. Helens Washington 

1201-

05- N 4612 W 12211 8363 CVO Seattle Kansas City Portland 

West Crater Washington 

1201-

06- N 4553 W 12205 4360 CVO Seattle Kansas City Portland 

Bachelor Oregon 

1202-

09- N 4359 W 12141 9065 CVO Seattle Kansas City Pendleton 

Belknap Oregon 

1202-

06- N 4417 W 12150 6874 CVO Seattle Kansas City 

Portland & 

Pendleton 

Blue Lake 

Crater Oregon 

1202-

03- N 4425 W 12146 4036 CVO Seattle Kansas City 

Portland & 

Pendleton 

Cinnamon 

Butte Oregon 

1202-

15- N 4314 W 12206 6418 CVO Seattle Kansas City Medford 

Crater Lake Oregon 

1202-

16- N 4256 W 12207 8160 CVO Seattle Kansas City Medford 

Davis Lake Oregon 

1202-

10- N 4334 W 12149 7097 CVO Seattle Kansas City 

Medford & 

Pendleton 

Devils 

Garden Oregon 

1202-

12- N 4331 W 12052 5571 CVO Seattle Kansas City Medford 

Diamond 

Craters Oregon 

1202-

17- N 4306 W 11845 4708 CVO Seattle Kansas City Boise 

Four Craters 

Lava Field Oregon 

1202-

14- N 4322 W 12040 4925 CVO Seattle Kansas City Medford 

Hood Oregon 

1202-

01- N 4522 W 12142 11241 CVO Seattle Kansas City Portland 

Jackies Butte Oregon 

1202-

20- N 4236 W 11735 4652 CVO Seattle Kansas City Boise 

Jefferson Oregon 

1202-

02- N 4442 W 12148 10496 CVO Seattle Kansas City 

Portland & 

Pendleton 

Jordan 

Craters Oregon 

1202-

19- N 4309 W 11728 4833 CVO Seattle Kansas City Boise 

Lava 

Mountain Oregon 

1202-

13- N 4328 W 12045 5614 CVO Seattle Kansas City Medford 

Newberry 

Volcano Oregon 

1202-

11- N 4343 W 12114 7986 CVO Seattle Kansas City Pendleton 

North Sister 

Field Oregon 

1202-

07- N 4410 W 12146 10086 CVO Seattle Kansas City 

Portland & 

Pendleton 

Sand Mtn 

Field Oregon 

1202-

04- N 4423 W 12156 5460 CVO Seattle Kansas City Portland 

South Sister Oregon 

1202-

08- N 4406 W 12146 10358 CVO Seattle Kansas City 

Portland & 

Pendleton 

Washington Oregon 

1202-

05- N 4420 W 12150 7796 CVO Seattle Kansas City 

Portland & 

Pendleton 

Amboy California 

1203-

20- N 3433 W 11547 945 LVO Los Angeles Kansas City Las Vegas 

Big Cave California 

1203-

04- N 4057 W 12122 4131 CVO Oakland Kansas City Sacramento? 

Brushy Butte California 

1203-

03- N 4111 W 12127 3852 CVO Oakland Kansas City 

Medford & 

Sacramento 

Clear Lake California 

1203-

10- N 3858 W 12246 4721 LVO Oakland Kansas City Sacramento 

Coso Volc 

Field California 

1203-

18- N 3602 W 11749 7874 LVO Los Angeles Kansas City Las Vegas 
D-6 

Volcano 

Name State Number 

Latitude 

DDMM 

Longitude 

DDDMM 

Elev. 

feet VO ARTCC MWO WFO 

Eagle Lake 

Field California 

1203-

09- N 4038 W 12050 5420 CVO Oakland Kansas City Reno 

Golden Trout 

Creek California 

1203-

17- N 3621 W 11819 9469 LVO Los Angeles Kansas City Las Vegas 

Inyo Craters California 

1203-

13- N 3742 W 11901 8626 LVO Oakland Kansas City Reno 

Lassen Volc 

Center California 

1203-

08- N 4030 W 12130 10457 CVO Oakland Kansas City Sacramento 

Lavic Lake California 

1203-

19- N 3445 W 11638 4905 LVO Los Angeles Kansas City Las Vegas 

Long Valley California 

1203-

14- N 3742 W 11852 11123 LVO Oakland Kansas City Reno 

Medicine 

Lake California 

1203-

02- N 4135 W 12134 7914 CVO Oakland Kansas City Medford 

Mono 

Craters California 

1203-

12- N 3753 W 11900 9174 LVO Oakland Kansas City Reno 

Mono Lake 

Volc Field California 

1203-

11- N 3800 W 11902 6959 LVO Oakland Kansas City Reno 

Red Cones California 

1203-

15- N 3735 W 11903 9016 LVO Oakland Kansas City Reno 

Shasta California 

1203-

01- N 4125 W 12212 14164 CVO Oakland Kansas City Medford 

Tumble 

Buttes California 

1203-

06- N 4041 W 12133 7189 CVO Oakland Kansas City Sacramento 

Twin Buttes California 

1203-

05- N 4047 W 12136 5351 CVO Oakland Kansas City Sacramento 

Ubehebe 

Craters California 

1203-

16- N 3701 W 11727 2467 LVO Los Angeles Kansas City Las Vegas 

Craters of 

the Moon Idaho 

1204-

02- N 4325 W 11330 6578 YVO 

Salt Lake 

City Kansas City Pocatello 

Hell's Half 

Acre Idaho 

1204-

04- N 4330 W 11227 5351 YVO 

Salt Lake 

City Kansas City Pocatello 

Shoshone 

Lava Field Idaho 

1204-

01- N 4311 W 11421 4849 YVO 

Salt Lake 

City Kansas City Pocatello 

Wapi Lava 

Field Idaho 

1204-

03- N 4253 W 11313 5263 YVO 

Salt Lake 

City Kansas City Pocatello 

Yellowstone Wyoming 

1205-

01- N 4426 W 11040 9203 YVO 

Salt Lake 

City Kansas City Riverton 

Steamboat 

Springs Nevada 

1206-

01- N 3923 W 11943 4643 LVO Oakland Kansas City Reno 

Bald Knoll Utah 

1207-

03- N 3720 W 11224 7005 YVO 

Salt Lake 

City Kansas City Salt Lake City 

Black Rock 

Desert Utah 

1207-

05- N 3858 W 11230 5906 YVO 

Salt Lake 

City Kansas City Salt Lake City 

Markagunt 

Plateau Utah 

1207-

04- N 3735 W 11240 9318 YVO 

Salt Lake 

City Kansas City Salt Lake City 

Santa Clara Utah 

1207-

01- N 3715 W 11338 4807 YVO 

Salt Lake 

City Kansas City Salt Lake City 

Dotsero Colorado 

1208-

01- N 3901 W 10702 7317 YVO Denver Kansas City 

Grand 

Junction 

Uinkaret 

Field Arizona 

1209-

01- N 3623 W 11308 5102 YVO Los Angeles Kansas City Las Vegas 
D-7 

Volcano 

Name State Number 

Latitude 

DDMM 

Longitude 

DDDMM 

Elev. 

feet VO ARTCC MWO WFO 

Sunset 

Crater Arizona 

1209-

02- N 3522 W 11130 8029 YVO Albuquerque Kansas City Flagstaff 

Carrizozo New Mexico 

1210-

01- N 3347 W 10556 5679 YVO Albuquerque Kansas City Albuquerque 

Valles 

Caldera New Mexico 

1210-

03- N 3552 W 10634 11254 YVO Albuquerque Kansas City Albuquerque 

ZuniBandera New Mexico 1210-

02- N 3448 W 10800 8367 YVO Albuquerque Kansas City Albuquerque 

Kilauea Hawaiian Is 

1302-

01- N 1926 W 15518 4009 HVO Honolulu Honolulu Honolulu 

Haleakala Hawaiian Is 

1302-

06- N 2042 W 15615 10023 HVO Honolulu Honolulu Honolulu 

Hualalai Hawaiian Is 

1302-

04- N 1942 W 15552 8278 HVO Honolulu Honolulu Honolulu 

Mauna Kea Hawaiian Is 

1302-

03- N 1949 W 15528 13797 HVO Honolulu Honolulu Honolulu 

Mauna Loa Hawaiian Is 

1302-

02= N 1929 W 15536 13682 HVO Honolulu Honolulu Honolulu 

Agrigan Mariana Is 

0804-

16= N 1846 E 14540 3166 HVO Honolulu Honolulu Guam 

Ahyi Mariana Is 

0804-

141 N 2025 E 14502 -449 HVO Honolulu Honolulu Guam

Alamagan Mariana Is 

0804-

18= N 1736 E 14550 2441 HVO Honolulu Honolulu Guam

Anatahan Mariana Is 

0804-

20= N 1621 E 14540 2585 HVO Honolulu Honolulu Guam

Asuncion Mariana Is 

0804-

15= N 1940 E 14524 2812 HVO Honolulu Honolulu Guam

Esmeralda 

Bank Mariana Is 

0804-

21= N 1500 E 14515 -141 HVO Honolulu Honolulu Guam

Farallon de 

Pajaros Mariana Is 

0804-

14= N 2032 E 14454 1181 HVO Honolulu Honolulu Guam

Guguan Mariana Is 

0804-

19= N 1719 E 14551 942 HVO Honolulu Honolulu Guam

Maug Islands Mariana Is 

0804-

143 N 2001 E 14513 745 HVO Honolulu Honolulu Guam

Pagan Mariana Is 

0804-

17= N 1808 E 14548 1870 HVO Honolulu Honolulu Guam

Ruby Mariana Is 

0804-

201 N 1537 E 14534 -755 HVO Honolulu Honolulu Guam

Sarigan Mariana Is 

0804-

191 N 1642 E 14547 1765 HVO Honolulu Honolulu Guam

Supply Reef Mariana Is 

0804-

142 N 2008 E 14506 -26 HVO Honolulu Honolulu Guam

Federal Committee for Meteorological Services and Supporting Research 

National Aviation Weather Program Council 

Committee for Aviation Services and Research 

Working Group for Volcanic Ash 

Subject Matter Experts: 

Ms. Gail Carter, Federal Aviation Administration

Mr. Jamie Kibler, NOAA National Environmental Satellite, Data, and Information Service

Capt. Edward K. Miller (retired), Air Line Pilots Association 

Mr. John Murray, National Aeronautics and Space Administration

Dr. David Rhodenhuis, Federal Aviation Administration

Mr. Len Salinas, United Airlines Dispatch

Mr. George Stephens, NOAA National Environmental Satellite, Data, and Information Service

Mr. Chris Strager, NOAA National Weather Service

Ms. Davida Street, NOAA National Environmental Satellite, Data, and Information Service 

Mr. Steven Albersheim 

Aerospace Weather Policy 

and Standards 

Federal Aviation Administration 

Department of Transportation 

Ms. Marianne C. Guffanti 

Volcano Hazards Program 

U.S. Geological Survey 

Department of Interior 

Ms. Barbara J.B. Stunder 

Air Resources Laboratory 

Office of Oceanic and Atmospheric Research 

National Oceanic and Atmospheric Administration 

Department of Commerce 

Mr. Jeffrey M. Osiensky 

National Weather Service 

National Oceanic and Atmospheric Administration 

Department of Commerce 

Mr. Charles R. Holliday 

Air Force Weather Agency 

United States Air Force 

Department of Defense 

Ms. Grace Swanson 

Washington Volcanic Ash Advisory Center 

National Oceanic and Atmospheric 

Administration/NESDIS 

Department of Commerce 

Mr. John A. Haynes 

Aviation Applications Program 

Science Mission Directorate 

National Aeronautics and Space Administration 

Dr. Richard Wunderman 

Global Volcanism Program 

Department of Mineral Sciences 

National Museum of Natural History 

Smithsonian Institution 

Mr. Anthony R. Ramirez 

Executive Secretary 

Office of the Federal Coordinator for 

Meteorological Services and Supporting Research 

Science and Technology Corporation

Ms. Mary M. Cairns 

(Former) Executive Secretary 

Office of the Federal Coordinator for 

Meteorological Services and Supporting Research