Service Assessment

Record Tornado Outbreaks of 

May 4-10, 2003 

U.S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

National Weather Service

Silver Spring, Maryland
Cover Photographs:

Left: F4 tornado near Girard, Kansas, May 4, 2003. (Chuck Robertson)

Right: The tornado that moved through Girard later destroyed this home in Liberal, Missouri.

The gun safe in the center of the basement was used as shelter by the residents of the

home. None of the residents were injured. (Ken Harding, NOAA, NWS 

Aberdeen, South Dakota)
 

Service Assessment

Record Tornado Outbreaks of 

May 4-10, 2003

December 2003

U.S. DEPARTMENT OF COMMERCE

Donald L. Evans, Secretary

National Oceanic and Atmospheric Administration

Vice Admiral Conrad C. Lautenbacher, Jr., Administrator

National Weather Service

John J. Kelly, Jr., Assistant Administrator
ii

Preface

During the period May 4-10, 2003, an unprecedented number of tornadoes affected the

central and southern United States. During this period, 393 tornadoes occurred across the central

and southern U.S. resulting in 39 deaths across 4 states. Six of these tornadoes were classified as

violent (F4) on the Fujita Tornado Intensity Scale.

Due to the magnitude of this event, a service assessment team was formed to examine the

warning and forecast services provided to emergency managers (EMs), government agencies and

the public. Service assessments are used to improve techniques of National Weather Service

products and services to the American public through the recommendations in the report. 

John J. Kelly, Jr.

Assistant Administrator

 for Weather Services

December 2003
iii

Table of Contents

Page

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

Service Assessment Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv

Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi

Service Assessment Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Event Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Warning and Forecast Services

A. Storm Prediction Center (SPC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

B. WFO Pleasant Hill, Missouri . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

C. WFO Springfield, Missouri . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

D. WFO Memphis, Tennessee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

E. WFO Paducah, Kentucky . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

 F. WFO Norman, Oklahoma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

 G. Issues Common to All Five WFOs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Best Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Appendix A Fujita Tornado Intensity Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

Appendix B Direct Fatalities in Each WFO’s CWA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

Appendix C Event Statistics, May 4-10, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1
iv

Service Assessment Team

The Service Assessment team was activated on May 12, 2003. Team members visited

damage areas and interviewed emergency managers, the media, and public in Oklahoma,

Missouri, Tennessee and Kentucky, and visited five Weather Forecast Offices (WFOs) located in

Norman, Oklahoma, Kansas City and Springfield, Missouri, Memphis, Tennessee, and 

Paducah, Kentucky, and the Storm Prediction Center (SPC) also in Norman, Oklahoma. 

The following members were on the team.

Jim Purpura Team Leader, Meteorologist In Charge (MIC), WFO 

Corpus Christi, Texas

Steve Letro MIC, WFO Jacksonville, Florida

Larry Ruthi MIC, WFO Dodge City, Kansas

Stan Levine Warning Coordination Meteorologist (WCM), WFO 

Buffalo, New York

Dennis Decker WCM, WFO Melbourne, Florida

Chris Jones WCM, WFO Riverton, Wyoming

Paul Sisson Science and Operations Officer (SOO), WFO Burlington, Vermont

Kurt Van Speybroeck SOO, WFO Brownsville, Texas

Ken Harding SOO, WFO Aberdeen, South Dakota

Jon Mittelstadt SOO, WFO Pendleton, Oregon

John Ferree Warning Decision Training Branch (WDTB), Norman, Oklahoma

Marilu Trainor Western Region Headquarters (WRH), Public Affairs

Kent LaBorde National Oceanic and Atmospheric (NOAA) Public Affairs
v

Other valuable contributors include:

William Lerner NWS Headquarters, Office of Climate, Water, and Weather

Services (OCWWS), Silver Spring, Maryland

Linda Kremkau NWS Headquarters, OCWWS, Silver Spring, Maryland

Wayne Presnell NWS Headquarters, OCWWS, Silver Spring, Maryland

Larry Dunn MIC, WFO Salt Lake City, Utah

Paul Kirkwood Southern Region Headquarters

Larry Mooney MIC, WFO Denver/Boulder, Colorado

Steve Weiss Storm Prediction Center

Russ Schneider Storm Prediction Center
vi

Acronyms

AWIPS Advanced Weather Interactive Processing System

CDT Central Daylight Time

CRH Central Region Headquarters

CRS Console Replacement System

CWA County Warning Area

DAPM Data Acquisition Program Manager

EAS Emergency Alert System

EM Emergency Manager

E-SPOTTER Near real-time, web-based, two-way spotter and emergency manager

communication and reporting system.

HMT Hydrometeorological Technician

HP Hewlett Packard

HWO Hazardous Weather Outlook

IDP Individual Development Plan

ITO Information Technology Officer

LP1 Local Primary 1

LSR Local Storm Report

MCS Mesoscale Convective System

MIC Meteorologist in Charge

MIS Meteorological Information Specialist

NCF Network Control Facility

NCEP National Centers for Environmental Prediction

NOAA National Oceanic and Atmospheric Administration

NWR NOAA Weather Radio

NWS National Weather Service

OCWWS Office of Climate, Water, and Weather Services

ORPG Open Radar Product Generator

OST Office of Science and Technology

PRF Pulse Repetition Frequency

PSDA Post-Storm Data Acquisition

QRT Quick Response Team

RPCCDS Radar Product Central Collection Dissemination Service

SDM Station Duty Manual

SLS Redefining Statement

SOO Science and Operations Officer

SPC Storm Prediction Center

SPS Special Weather Statement

SRM Storm Relative Motion

SVR Severe Thunderstorm Warning

SVS Severe Weather Statement

SWA Severe Weather Alert
vii

TOR Tornado Warning

WCM Warning Coordination Meteorologist

WDM Warning Decision Making

WDSS Warning Decision Support System

WES Weather Event Simulator

WIN Weather Information Network

WFO Weather Forecast Office

ZFP Zone Forecast Product
1

Service Assessment Report

Executive Summary

An unprecedented series of tornado outbreaks occurred in portions of the Great Plains,

Midwest, and Mid-South of the U.S. during the week of May 4 through 10, 2003. During this

seven day period, there was a total of 393 tornadoes resulting in 39 deaths. Tornado outbreaks

producing violent (F4) tornadoes occurred on May 4 in the Weather Forecast Office (WFO)

Kansas City and Springfield, Missouri county warning areas (CWAs) and WFO 

Memphis, Tennessee CWA, and on May 6 in the WFO Paducah, Kentucky CWA. A violent

(F4) tornado occurred in Oklahoma City (WFO Norman CWA) May 8, and on May 9 a second

tornado (F3) also struck Oklahoma City. 

An assessment was made of the performance of the National Centers for Environmental

Prediction’s (NCEP) Storm Prediction Center (SPC), which is responsible for issuing severe

weather outlooks and watches. Performances of the five WFOs responsible for issuing outlooks

and warnings in the counties where the violent tornadoes occurred, was also assessed. Due to

the magnitude of this event, the scope of the assessment was limited to the outbreak days of 

May 4, 6, 8 and 9, the SPC, and these five WFOs. 

The service assessment team found the assessment process is working well for the NWS.

SPC and all WFOs had anticipated the event in advance, adjusted staffing appropriate to the

event, and let the public, emergency managers and the media know of the potential for severe

weather and its impact. SPC and all five WFOs had read the Veteran’s Day Weekend Tornado

Outbreak of November 9-11, 2002 service assessment report, which had been distributed in 

April 2003, before the outbreaks in May began, and had either made improvements to severe

weather operations based on the assessment’s facts, findings, and recommendations, or already

had these improvements in place. Media, emergency management, and the public interviewed

by the service assessment team had praise for the outlooks, statements, watches, and warnings

issued before and during the event.

A high level of service was noticed by Congress as well. On June 10, 2003, the NWS

received a letter signed by 11 members of the House of Representatives’ House Science

Committee stating, “...many of your employees in the hardest hit areas literally lived in their

weather offices, working long, stressful hours to issue the warnings that saved lives...” and “We

greatly appreciate the outstanding service your agency provides to this nation and the lives you

save every day.”

The atmospheric features causing this extended tornado outbreak were predicted well in

advance in most cases. This allowed NWS offices to plan ahead and perform at the high level

noted. However, in some instances, the features leading to a tornado outbreak are not as evident
2

and can not be predicted as far in advance, giving NWS offices less time to prepare. Such a high

level of performance can not be expected with each tornado outbreak. 

During the entire 7 day period, the Probability of Detection (POD) for all tornadoes

occurring in all CWAs of the 5 WFOs was .910 and the False Alarm Ratio (FAR) was .722. The

average lead time for all Tornado Warnings from all 5 WFOs was 19 minutes with 70 of 73

tornadoes preceded by Tornado Warnings. The Tornado Watch average lead time to tornadoes

producing fatalities during the 7 day period was 2 hours and 3 minutes. Tornado Watches are

issued by the SPC. All of these values are better than national averages. 

The upper level wind pattern during the week of May 4-10 was characterized by a

persistent low pressure area over the western half of the United States, with a series of strong 

mid-level storm systems moving east daily into the central and southern Plains, and then

northeast into the upper Mississippi Valley. This did not change until May 11-12 when the

overall pattern shifted toward New England and an upper ridge of high pressure developed over

the Rocky Mountains, ending the series of unusually active severe weather days. At the surface,

a warm, moist, and unstable airmass was present across the central and southern Plains and east

across the Ohio Valley and the southeast United States during the entire outbreak period. This

persistent large scale pattern was accompanied by very strong west-southwest winds in the

middle and upper atmospheric levels across the tornado outbreak area. All these elements

combined to make ideal conditions for tornadoes across the Great Plains, Ohio Valley, and the

southeast United States.

 All 39 fatalities occurred within the boundaries of both watches and warnings.

 The five WFOs had an average lead time of 19 minutes for tornadoes occurring in their

CWAs during their respective outbreak days.

 Hazardous Weather Outlooks warned of the potential for severe weather as much as six

days in advance.

 Violent tornadoes killed only one person in Kansas City, and none in Oklahoma City,

even though they moved through densely populated areas. Media partnerships with the

NWS in these cities meant a consistent warning message reached the public through the

media. 

 Rick Mitchell, KOCO-TV in Oklahoma City said “It was like they knew what was going

to happen!”

 D.C. Rogers Clay County, Missouri Emergency Management said “There were no

surprises.”

Service Assessments are undertaken by the NWS to determine the level of service

provided to customers and partners. Best practices are identified for use throughout the NWS
3

when feasible. Service lapses, if any, are noted and recommendations for corrective actions are

made. Emergency managers, people in the media, and local residents were interviewed to obtain

feedback on NWS performance. 

As noted, NWS customers and partners were satisfied with services before and during the

outbreak, often expressing their gratitude for the high level of performance provided. This

report identifies 9 recommendations for improvements within the NWS severe weather warning

process. 

When implemented, the recommendations should allow for: 1) improved live

broadcasting of real time severe weather reports on NOAA Weather Radio (NWR); 2) increasing

the number of participants on conference calls which notify customers and partners of expected

hazardous weather; 3) improved interpretation of radar velocity data; 4) increased bandwidth

between Department of Defense (DOD) and NWS radars; 5) quicker methods of switching to

backup communication systems at the WFOs if the main one fails; 6) sufficient bandwidth to

provide customers and partners radar images during dissemination problems; 8) a summary of

Local Storm Reports (LSR) issued shortly after a major storm event ends and 9) quicker posting

of post event information on NWS Internet sites. 

Data contained in this report were compiled by the assessment team as of July 20, 2003. 

Final analyses may produce statistics not matching those contained in this report. 
4

Event Overview

Introduction

During the week of May 4-10, 2003, a record number of tornadoes occurred over the

central and eastern United States, with 393 tornadoes reported in 19 states. Eight tornadoes

caused 39 deaths, including 37 on May 4. The previous most active week on record was 

May 12-18, 1995, when there were 171 tornadoes reported. From May 4 through May 10,

National Weather Service Forecast Offices issued a total of 4,050 severe convective weather

warnings, with 1,090 Tornado Warnings and 2,960 Severe Thunderstorm Warnings issued. This

is the most in any seven day period. On May 6 alone, 921 warnings were issued, which is the

largest one day total since warning records began in 1986. The Storm Prediction Center issued

123 Tornado and Severe Thunderstorm Watches during this 7 day period, including 25 Tornado

Watches that contained the rarely used “Particularly Dangerous Situation” wording, which is

reserved for the most life threatening situations. At least 12 watches were issued each day

during this period, including three days when 20 or more watches were issued (May 6, 8, and

10). Perhaps most remarkably, severe weather watches were in effect continuously from 

11:40 a.m. CDT May 4 through 7:00 a.m. CDT May 9, a period of more than 115 hours. 

Although it is not uncommon for significant severe tornado episodes to occur during the early

part of May (in fact, the climatological frequency of a significant tornado day occurring in the

central U.S. is maximized at this time of year), it is extremely unusual for significant severe

convective weather to occur almost every day for a seven day period. 

NCEP’s Global Forecast System (GFS) computer model began to portray an extensive

upper level trough of low pressure developing over the western United States, indicating a

favorable pattern for severe weather episodes, 5-6 days prior to the beginning of the week of 

May 4. The GFS and another NCEP computer forecast model, the Eta, continued to indicate this

trend up to and through the 7 day period, providing strong guidance in forecasting the potential

for a period of widespread severe weather. 

 

Synoptic and Mesoscale Overview

The upper level wind pattern during the week of May 4-10 was characterized by a

persistent area of low pressure over the western half of the United States, with a series of strong 

mid-level storm systems moving east daily into the central and southern Plains, and then

northeast into the upper Mississippi Valley. This did not change until May 11-12 when the

pattern shifted toward New England and an upper ridge of high pressure developed over the

Rocky Mountains, ending the series of unusually active severe weather days. A warm, moist

airmass remained from across the central and southern Plains east across the Ohio Valley and the

southeast United States.

This persistent large scale pattern was accompanied by very strong west-southwest winds

in the middle and upper atmospheric levels across the tornado outbreak area. These strong winds

combined with persistent warm, moist surface conditions, significant change in wind speed and
5

direction with height and instability to create ideal conditions for tornado development across the

Great Plains, Ohio Valley, and the southeast United States.

A closer look at the four most active tornado producing days during the week-long event

is provided in the next section.

A Closer Look at Individual Outbreak Days

May 4

 May 4 was the most active tornado day, with 94 tornadoes reported (Figure 1),

including seven tornadoes that produced 37 fatalities. A total of 518 severe storm reports were

received by the SPC that day. A vigorous storm system in the middle levels of the atmosphere

moved northeast across the northern and central Plains toward the Mississippi Valley during the

afternoon and evening hours, contributing to a widespread region of severe weather extending

from the central Plains into the Tennessee Valley (Figure 2). A deep surface low was in place

over extreme northeast Kansas, with a cold front/dry line extending south and southwest from

the low, and a warm front extending southeast from the low into the Tennessee Valley. The

surface low combined with a vigorous mid-level storm system which moved northeast across the

Great Plains during the afternoon and evening hours to spawn a widespread region of severe

weather extending from the central plains into the Tennessee Valley. 

May 6

Sixty three tornadoes and a total of 533 severe weather reports were received on May 6

during an outbreak that covered a large part of the southeastern quarter of the nation (Figure 3). 

There was one killer tornado that struck southern Illinois resulting in two fatalities. Mid-level

analysis shows the winds were similar to the pattern just two days earlier, with a strong storm

system moving across the northern and central Plains (Figure 4). Strong southwest winds aloft

combining with warm, moist low level air were observed across the central and southern Plains

into the Ohio and Tennessee Valleys. A surface low was over southwest Missouri, and its

associated cold front, warm front, and dryline were the focus for severe storm development on

this day. 

May 8

Fifty four tornadoes and 313 total severe storm reports were received on May 8,

extending along an east to west axis from eastern Colorado into the Ohio Valley, with a separate

area of severe storms over eastern Virginia (Figure 5). Although no fatalities were caused by

tornadoes on this day, a violent (F4) tornado struck the southern Oklahoma City metropolitan

area during the afternoon rush hour, including parts of Moore, Oklahoma which were affected by

a devastating F5 tornado on May 3, 1999. The mid-level chart in Figure 6 is similar to patterns

earlier in the week, with a strong storm system lifting northeast across the central Plains and a

band of very strong southwest winds from California across the central Plains. Once again, the
6

surface conditions were warm and humid over the Plains creating favorable conditions for severe

storms.

May 9

Thirty five tornadoes and 444 total severe storm reports were received on May 9,

stretching in a large arc from southwest Texas across the middle Mississippi and Ohio Valleys

then into Virginia and North Carolina (Figure 7). The Oklahoma City metropolitan area was

struck by a significant tornado (an F3) for the second day in a row, an extremely rare occurrence. 

A strong low pressure area deepened over the Great Basin as a downstream high pressure

area built northward toward the Great Lakes, and an upper low moved northeast into the upper

Mississippi Valley (Figure 8). This resulted in a broad mid level jet stream extending from the

Plains into the Mississippi Valley and Great Lakes areas. A surface low was located over 

Lake Michigan, with a warm front extending southeast from the low into Virginia, and a cold

front trailed southwest from the low into a second low over the Oklahoma Panhandle. A dryline

extended southward over west Texas, with warm moist air to the east of the dryline over much of

Oklahoma and Texas. 

The intense mid-level storm system seen over the Great Basin in Figure 8 would prove to

be the last in a week long series of storms that moved from the Pacific Ocean into the western

U.S., and eventually across the central states. 
7

Figure 1. Tornado Reports in the U.S. for May 4, 2003. Courtesy of SPC. 

Figure 2. Composite Radar Reflectivity, Surface Fronts, 500 millibar and 850 millibar jet

streams at 0000 UTC, (7:00 p.m. CDT May 4, 2003) May 5, 2003. Courtesy of SPC. 
8

Figure 3. Tornado Reports in the U.S. for May 6, 2003. Courtesy of SPC.

Figure 4. Composite Radar Reflectivity, Surface Fronts, 500 millibar and 850 millibar jet

streams at 0000 UTC, (7:00 p.m. CDT May 6, 2003) May 7, 2003. Courtesy of SPC. 
9

Figure 5. Tornado Reports in the U.S. for May 8, 2003. Courtesy of SPC.

Figure 6. Composite Radar Reflectivity, Surface Fronts, 500 millibar and 850 millibar jet

streams at 0000 UTC, (7:00 p.m. CDT May 8, 2003) May 9, 2003. Courtesy of SPC.
10

Figu re

7. Tornado Reports in the U.S. for May 9, 2003. Courtesy of SPC.

Figure 8. Composite Radar Reflectivity, Surface Fronts, 500 millibar and 850 millibar jet

streams at 0000 UTC, (7:00 p.m. CDT May 8, 2003) May 9, 2003. Courtesy of SPC.
11

The following sections describe the chronology of events at the SPC and the five WFOs

where F4 tornadoes occurred in their CWAs. No F5 (strongest category on the Fujita Intensity

Scale) tornadoes occurred during this outbreak. The WFO sections are arranged chronologically

beginning with WFOs Pleasant Hill, Springfield, and Memphis on May 4, WFO Paducah on 

May 6, and WFO Norman on May 8 and 9. The quality of service provided and any issues

needing attention are discussed. Findings and recommendations, where appropriate, are included

at the end of each section. A section “Issues Common to All WFOs” was added and followed by

“Best Practices.” Preliminary Event Statistics from each WFO are provided in Appendix C. 

Warning and Forecast Services

A. Storm Prediction Center (SPC)

Overview

The assessment team received emphatic, positive comments regarding Storm Prediction

Center (SPC) service and skill during the week of May 4 through May 10. These comments

came from NWS forecasters, emergency managers, media, and the general public. 

Gary England, Oklahoma City KWTV Meteorologist, stated, “I check the day one outlook every

morning and night; it is like our bible...It’s excellent. On the (May) 8 and 9 (Oklahoma City

tornadoes) SPC did an excellent job.” 

Statistics back up these general perceptions. All 39 tornado-related fatalities occurred

within the bounds of an SPC Tornado Watch. Of the eight tornadoes that caused fatalities, seven

were within the bounds of an SPC high risk outlook, and one occurred just outside the bounds of

the high risk area but within a moderate risk outlook. The average lead time from tornado watch

issuance to first tornado in watches where fatalities occurred was 2 hours, 3 minutes. The

following table shows lead times in hours and minutes for the watches and outlooks that covered

locations where tornado fatalities occurred.

Day of Month Tornado Watch # Lead Time to First Tornado

4 232* 3:05

4 233 2:43

4 237 1:58

4 239 0:54

6 275 1:35

* Tornado Watch 232 was replaced by Tornado Watch 237 at 6:05 p.m.
12

The widespread and frequent nature of the convective weather during the week required

the issuance of a large number of products. SPC issued 217 Mesoscale Discussions during the

week, an average of 10 discussions per each eight-hour shift. A total of 127 Tornado or Severe

Thunderstorm Watches were coordinated with forecast offices and issued. Several times during

the week, four watches were coordinated and issued within a one hour period. SPC staff

successfully utilized technological and human resources to issue this large number of products with

sufficient lead times. 

In addition to the standard suite of SPC products, services were provided via the Internet

and telephone. The number of Internet visitors to the SPC web site averaged just over 5.6 million

hits per day (a hit is defined as an object downloaded from a web page). During the week, SPC

provided background information and interviews for more than 70 wire services, and national,

international and local media.
13

Veteran’s Day Weekend Tornado Outbreak of November 9-11, 2002 Recommendations

A service assessment report for the Veteran’s Day Weekend Tornado Outbreak of

November 9-11, 2002, released in April 2003, contained several recommendations for SPC 

(See table below). SPC has already completed or made progress in most areas and as a result,

actions from recommendations 2a and 2b were implemented during this event with success. 

Recommendations SPC Actions 

Recommendation 1: The Office of Climate,

Water, and Weather Services (OCWWS),

SPC, and the regions should review policy on

issuing or upgrading weather watches for

WFOs already in warning operations. 

NWSI 10-512 will update the policy on

issuing or upgrading weather watches for

WFO’s already in warning operations. NWSI

10-512 will become effective October 1, 2003. 

Recommendation 2a: The SPC should modify

its SDM to provide guidance when extra staff

should be brought in to handle the workload

associated with a major outbreak by

September 1, 2003. 

Completed. The SDM has been modified

accordingly. Extra staff was used during the

May 4-10 period: The need for extra staff was

discussed and anticipated, and as needed extra

staff was called in during the weekend,

forecasters came in early, and forecasters were

held over at the end of shifts.

Recommendation 2b: The SPC should

reconfigure its operations area to handle

simultaneous multiple watch issuances by

multiple forecasters by September 1, 2003.

Completed. A second workstation was

implemented and has been utilized to

successfully prepare, coordinate and issue

simultaneous watches.

Recommendation 2c: The SPC should

reexamine its policy of allowing only lead

forecasters to be certified to issue watches.

Any changes should be completed by

September 1, 2003. 

 An SPC Forecaster Familiarization Program

for GS-13 forecasters was implemented May

15, 2003. Training is underway and some

participants have issued watches under the

supervision of Lead Forecasters. 

Recommendation 3: The SPC should modify

its training program to include Weather Event

Simulator (WES)-like simulations of major

severe weather outbreaks.

SPC expects to be able to have a system to

view historical data using N-AWIPS. This

requires NCEP- Operations Computer

Development Branch (NCO-CDB)

development. Target date for completion is

September 10, 2003. 
14

B. WFO Pleasant Hill, Missouri 

Overview

Significant severe weather struck the Kansas City metropolitan area during the afternoon

and evening of Sunday, May 4. Nine tornadoes (2 F-4s, 3 F-2s, 3 F-1s, and 1 F-0) as well as

large hail swept across the WFO Pleasant Hill (Kansas City), Missouri CWA over 9 hours. All

nine tornadoes were covered by Tornado Warnings. The average lead time for Tornado

Warnings was 24 minutes, with a range from 8 to 33 minutes. Only one storm fatality occurred. 

In Wyandotte County, Kansas, an 81-year-old man was crushed by debris as he headed for

shelter while his house collapsed during the tornado. There were 43 people injured. The fatality

and injury totals were minimal, considering the violent (F4) tornadoes touched down within

densely populated portions of suburban Kansas City. 

The WFO Pleasant Hill staff first mentioned severe weather potential for May 4 in the

early morning Hazardous Weather Outlook (HWO), issued on Monday, April 28. Subsequent

HWO products continued to mention the severe weather potential, gradually refining timing,

location, and forecast confidence. The HWO issued at 6 a.m. CDT, Saturday, May 3, noted an

increasingly favorable environment for large hail and isolated tornadoes. The next issuances of

the HWO contained headlines, highlighting a severe weather outbreak Sunday afternoon, May 4. 

This was in addition to a high risk area over eastern Kansas and western Missouri in the early

morning Convective Outlook issued by SPC at 7:53 a.m. CDT, Sunday, May 4. The SPC issued

Tornado Watch 233, with the headline, “this is a particularly dangerous situation,” for the

area at 12:45 p.m. CDT, valid through 7 p.m. CDT. The WFO Pleasant Hill senior forecaster

notified all off duty personnel after the Tornado Watch was issued. 

Situational awareness was high, and pre-planning and coordination allowed for effective,

efficient operations during the severe weather event. The updated public forecast issued at

1:22 p.m. CDT, Sunday, May 4, added the text “some thunderstorms may become severe with

large hail, damaging winds and isolated tornadoes.” 

The first warning, a Severe Thunderstorm Warning, was issued at 2 p.m. CDT. The final

warning expired at 11 p.m. During the event, 44 warnings (23 Tornado and 21 Severe

Thunderstorm) were issued, in addition to 107 Severe Weather Statements, 97 Short-Term

Forecasts, and 100 Local Storm Reports. The Tornado Warning for Clinton and Clay Counties

in Missouri stated, “a damaging tornado has been confirmed with the storm! This is a lifethreatening situation.” Several timely Severe Weather Statements were issued for every

Tornado Warning, with numerous statements providing specific tornado locations from spotter

reports and emphasizing a “tornado emergency for the northern half of the Kansas City

metro area.” 
15

This housing subdivision in north Kansas City suffered major damage on May 4. 

The Senior Forecaster and MIC (acting as the Warning Coordinator) delegated warning,

communications, and forecast duties. A total of 15 meteorologists worked the event, including

two meteorologists from Central Region Headquarters (CRH). The MIC, SOO, and Information

Technology Officer (ITO) were present from the management staff. Four amateur radio

operators also worked during the event to assure a steady supply of spotter reports to the warning

forecasters. 

A total of three teams consisting of seven meteorologists worked as radar/warning

meteorologists and Meteorological Information Specialists (MIS). The MIS is paired with a

warning forecaster to collect and disseminate information for his/her warning sector. The

philosophy of sectorizing the CWA assisted some radar warning teams in focusing on the most

damaging storms while others were concurrently warning on lesser severe storms.

WFO Topeka, Kansas, the backup office, assumed WFO Pleasant Hill’s aviation forecast

responsibility during the outbreak allowing the Pleasant Hill staff to concentrate on severe

weather services for the CWA. 
16

Pre-planning and intra-office coordination resulted in a smooth transition from nonsevere weather, through severe weather and into an emergency situation. Leadership from local

management through the Senior Forecasters produced timely decisions regarding staffing and

division of duties among the entire operations area. Pre-event and severe weather operational

checklists were completed the evening before the event and the day of the event. The ITO was

called in the night before the event and did a total restart of all AWIPS workstations. This

appeared to contribute to stable AWIPS operation during the event. Before severe weather

began, all communications systems were checked and the AWIPS Network Control Facility

(NCF) was notified and asked to list the WFO as being in “critical weather watch mode.” The

presence of a warning coordinator, operational teams of radar operators and several MIS’s, and

predefined severe weather shift duties, in “flash card” form, allowed the operational staff to

quickly focus on specific duties with knowledge that all necessary tasks were being completed. 

This practice minimized duplication of effort and maximized warning and communications

performance.

The staff received several training sessions in severe weather in 2003. The operations

staff had Warning Event Simulator (WES) training in February and March. The simulation

included long-track supercells. In March, a severe weather seminar on warning guidance and

severe weather forecast parameters was conducted, and in April, a climatology of Mesoscale

Convective Systems (MCSs) seminar was presented.

Outreach and community preparedness activities by the Pleasant Hill WFO have been

aggressive. Two counties (Leavenworth and Johnson in Kansas) are StormReady counties. Four 

municipalities in the Kansas City area (Lee’s Summit, Peculiar, Belton, and Knob Knoster) are

designated as StormReady cities. Discussions with emergency managers provided numerous

examples of how timely training and collaboration between local governments, businesses, and

the local WFO effectively saved lives. D. C. Rogers, the Director of Emergency Management in

Clay County, Missouri, stated, “There were no surprises!”

Project Community Alert, a joint venture between the Metropolitan Emergency

Manager’s Committee (MEMC) and the NWS helped to market NWRs at reduced prices in the

Kansas City area. At least 20,000 NWRs were sold in the Kansas City area from June 2002

through May 2003. 

Television media and emergency management interviewed by the assessment team (four

network television stations and five Emergency Managers) were extremely satisfied with the

level of service by WFO Pleasant Hill. The network stations provided continuous live coverage

of the tornado event by broadcasting Tornado Warnings, Severe Thunderstorm Warnings, Severe

Weather Statements, and Local Storm Reports from the WFO. The WFO issued these products

at intervals averaging 2 to 3 minutes at the peak of the event. Some of the media did mention

they would appreciate a summary of the Local Storm Reports at the end of the event to assure

they had all of the NWS reports (Recommendation 8). The QRT process took longer than

expected in getting the final rating to the media, but WFO Pleasant Hill kept the media informed
17

as the process continued, and held a press conference to announce the final F4 ratings for the

strongest tornadoes.

Gary Lezak, meteorologist for KHSB-TV, said it was a “solid ‘A’ effort by the NWS.” 

The assessment team also spoke to representatives of two companies representing eleven

radio stations in the Kansas City area, including the Emergency Alert System (EAS) Local

Primary 1 (LP1) and the Chairman of the local EAS committee. The radio media interviewed

also had high praise for the warning services from WFO Pleasant Hill. However, an issue with

a live NWR broadcast from the WFO was noted (Recommendation 1). 

Issues

Fact: Live broadcasts from NWR were used frequently during the event, and were praised by

the broadcasters. 

Fact: During one live NWR broadcast, a Tornado Warning had just been issued and the

Specific Area Message Encoder (SAME) tones on NWR activated EAS. Several radio stations

played the NWS audio of the warning. 

Fact: Before the end tones shutting off the NWR broadcast on EAS were received by the radio

stations, the NWR operator began a live update. This live update was also broadcast on EAS

radio stations across Kansas City.

Fact: The end tones of the EAS, needed to resume normal broadcasting, were never received

and the commercial radio stations carried 1 to 2 minutes of “dead air” due to an open, live

microphone at the WFO. Several broadcasters mentioned this error to the assessment team.

Finding 1: A live update of a Tornado Warning on NWR began before the end tones of the

EAS broadcast occurred. This did not allow the EAS broadcast to end properly and

resume normal broadcasting, leading to commercial radio stations carrying 1 to 2 minutes

of “dead air” due to an open, live microphone at the NWR console of the WFO. 

Recommendation 1a: Regions should ensure all WFOs are aware of this potential issue

and instruct offices on ways to avoid it.

Recommendation 1b: The Office of Science and Technology (OST) of the NWS should find

a solution to the conflict between automated CRS broadcasts and live broadcasts. NWS

Training Division should develop training on the Console Replacement System (CRS) for

live broadcasts, including live transmission of end tones. 
18

C. WFO Springfield, Missouri 

Overview

A total of fifteen tornadoes occurred in the WFO Springfield, Missouri CWA on Sunday,

May 4 between 4:35 p.m. CDT and 10:40 p.m. CDT. Tornado intensities included the following

ratings: 1 F-4; 4 F-3s; 1 F-1; and 9 F-0s. Five of these tornadoes resulted in 25 deaths. Many of

the fatalities occurred in mobile homes, modular homes, and frame homes, and many of the

homes in southwest Missouri do not have basements. Less live media coverage (as compared to

the Kansas City metro area) may also have contributed to the high number of fatalities. A list of

the fatalities and circumstances surrounding the deaths is given in Appendix B. There were 186

persons injured. More than 3,000 homes and businesses were damaged by the tornadoes, and

preliminary property damage estimates exceeded $159 million. All of the tornadoes were

covered by Tornado Warnings. The average lead time was 23 minutes, with individual county

lead times ranging from 6 minutes to 53 minutes. 

The staff in the WFO Springfield first mentioned the severe weather potential in the 

May 1 HWO. The May 2 HWO highlighted the threat of isolated tornadoes for Sunday

afternoon, May 4. The Saturday, May 3 2:35 a.m. CDT Zone Forecast Product (ZFP) included

the headline “severe weather outbreak possible Sunday afternoon.” The headline was

changed at 7:54 a.m. CDT Sunday, May 4 to read “tornadic storms possible this afternoon.” 

The SPC Day 1 Outlook, issued at 8:09 a.m. CDT, upgraded the risk category for the entire 

Springfield CWA from moderate to high. The HWO at 11:10 a.m. May 4, called for Athe 

potential of strong and particularly damaging tornadoes.@

Conference calls were hosted by the WFO for emergency managers on Saturday evening

May 3 and at 10:00 a.m. CDT Sunday. A media conference call was hosted at 11:15 a.m. CDT

Sunday, May 4. The conference calls were highly praised by those who participated in them, but

limitations in conference calling capabilities at the WFO resulted in some inefficiencies. A

number of emergency managers were unable to join the first conference call Saturday evening

because all available ports were used. WFO Springfield hosted three separate conference calls

with small groups of emergency managers starting at 10:00 a.m. CDT Sunday. A separate

conference call with media representatives was conducted at 11:15 a.m. CDT Sunday

(Recommendation 2). 

WFO Springfield began planning for adequate staffing at 10:00 a.m. CDT, Saturday, 

May 3. A maximum of 12 people staffed WFO Springfield Sunday evening, including eight

Meteorologists, two Hydrometeorological Technicians (HMTs), the MIC, WCM, ITO, one ET

and two amateur radio operators. Each staff member=s role was well defined, and office

operations went smoothly during the outbreak. The Severe Weather Operations Plan was praised

by the Lead Forecasters for providing guidance regarding staffing and task assignments. All

staff members interviewed noted that they felt that staffing was adequate to handle the outbreak

but not excessive. 
19

A total of 33 Tornado Warnings and 25 Severe Thunderstorm Warnings were issued

covering 57 total counties beginning at 4:19 p.m. CDT Sunday, May 4 and ending at 2:33 a.m.

CDT Monday, May 5. In addition, 132 Severe Weather Statements (SVSs) were issued during

the outbreak, with multiple SVSs issued with each warning. Fifty nine real-time Local Storm

reports (LSRs) were disseminated by the WFO during the event. 

The WFO Springfield forecasters found the eight bit, full resolution Reflectivity and

Storm Relative Motion (SRM) products extremely helpful in diagnosing storm structure and

mesocyclone strength. Since the eight bit Reflectivity and SRM products can be combined only

on the LINUX workstations, only two radar operators were able to make operational use of the

combined imagery. The staff expressed some disappointment that the high resolution combined

imagery was not available at all workstations.

All operational systems worked well during the severe weather outbreak. The AWIPS

PX-2 failed on May 1 and was not restored to operational status until May 7 (PX-1 and PX-2

process incoming data for use in AWIPS). Since PX-1 provides redundancy, the loss of PX-2

did not have any adverse effects on operations.

 The WFO Springfield staff participated in a Severe Weather Science Seminar on 

April 1, 2003. Topics covered include; 1) the importance of mesoanalysis; 2) an overview of

office severe weather operating procedures; and 3) a review of a tornado outbreak that occurred

in the WFO Springfield CWA in December 2002. In addition, the WFO Springfield SOO led the

staff through a Warning Decision Making (WDM) Workshop training module. All forecasters

completed two WES severe weather training simulations. The two meteorologists that issued

most of the warnings during the outbreak cited the importance of the recent office

reconfiguration that placed the two Linux workstations side-by-side. This allowed for better

verbal communication between the warning forecasters. 

Spotter training was provided to 36 of 37 counties served by WFO Springfield, including

all ten counties in which fatalities occurred on May 4. During the period from January 2001

through early May 2003, WFO Springfield conducted 116 spotter training seminars. All of the

county emergency managers interviewed by the assessment team indicated that frequent contact

was made with WFO Springfield. 

Media and emergency management officials mentioned the importance of the

unprecedented conference calls that were initiated by WFO Springfield. They discussed the way

the advance information allowed them to adjust staffing and make contingency plans.

“250% of service above and beyond what is normally expected.” 

Jimmie Swaggerty, Cedar County Emergency Manager.

“(WFO Springfield is) the most professional group I have worked with.” 

Jim Wakeman, Operations Director, Missouri State Emergency Management Agency.
20

Media in the three main markets served by WFO Springfield were interviewed. All

 expressed satisfaction with the overall service provided by WFO Springfield and several noted

that WFO Springfield performed very well during the outbreak. Communication with WFO

Springfield was described by Gary Bandy, Chief Meteorologist at KSNF TV in Joplin, Missouri

as, Aexemplary.@ Morris James, news director for KTTS Radio, the Springfield LP1 station,

stated, “I have worked with a number of (NWS) offices, but by far, Springfield is the best.”

All of the media interviewed stated that in addition to the warnings, LSRs and SVSs were

read on-air during the tornado outbreak. Three television stations and six radio stations provided

continuous live coverage of the tornado outbreak, ranging from 90 minutes to nearly 10 hours.

All six of the radio stations had spotters in the field prior to the first warning. One spotter for a

station in southeast Kansas provided live reports of the F4 tornado that tracked across Crawford

County, Kansas. Of the media interviewed, only one television station chose not to increase

staffing as a result of the conference calls.

Reports were relayed from the public by telephone, instant messaging, and amateur radio. 

Another avenue that proved successful was an Internet-based software program called

 “E-Spotter” developed at WFO Paducah, Kentucky. A review of WFO Springfield=s

communication logs showed that the earliest reports of the rotating wall cloud and subsequent

tornado that struck Pierce City, Missouri, came via E-Spotter. Several emergency managers and

media personnel said that they use the WFO Springfield web site each day, particularly to view

the HWO.

Fact: Conference calls were extremely useful to both emergency managers and the Media to plan

staffing and develop other contingency plans.

Fact: The number of participants in each conference call was limited to 20 by the conference

call plan.

Fact: This limitation forced the WFO to host three separate conference calls Sunday morning

for emergency managers to assure that all available emergency managers could participate.

Finding 2: Limitations in conference call arrangement with telecommunication companies

lessened the effectiveness and efficiency of the conference call process.

Recommendation 2: The Regional Headquarters should work with any WFOs using

conference calls for hazardous weather briefings. The Regions should assure conference

call capabilities of the WFO are adequate for the anticipated number of participants in the

call. This should be done by June 1, 2004.
21

Major damage to the armory in Pierce City, Missouri
22

D. WFO Memphis, Tennessee

Overview

During the evening of May 4 and into early May 5, a series of tornadoes swept across the

WFO Memphis CWA. The most significant was an F-4 tornado that moved along an 18 mile

path, killing 11 (See Appendix B for a list of fatalities). There were 18 tornadoes (1 F-4, 2 F-3s, 

3 F-2s, 9 F-1s, and 3 F-0s) that moved across the area over a 6 hour period. All of the tornadoes,

that developed in the Memphis CWA May 4 and 5, were covered by Tornado Warnings, with the

exception of the Craighead County, Arkansas, tornado. This was a weak tornado that touched

down briefly before moving into Mississippi County, Arkansas. The average lead time for

Tornado Warnings was 20 minutes with a range from 0 to 41 minutes. There were also 70

injuries and $100,000,000 property damage reported from these tornadoes.

This section will focus on the two most damaging tornadoes that occurred on the night of

May 4 into May 5. The first was an F2 tornado that swept across Dyer County, and the towns of

Dyersburg and Newbern. The second was an F4 tornado that struck Jackson in Madison County

and continued on into Henderson County. 

On the evening of May 1, WFO Memphis products began indicating the potential for

severe weather. The 6:45 p.m. Hazardous Weather Outlook (HWO) focused on “strong to

severe thunderstorms” for the period Saturday through Tuesday. On May 3, the 3:44 a.m.

HWO indicated that some storms would be severe, especially on Sunday afternoon and Sunday

night, and that spotter activation would be likely. By 5:35 p.m. Saturday, the HWO mentioned a

moderate risk of severe weather for Sunday and Sunday night. The morning of the outbreak,

Sunday May 4, the HWO stated the main threat would be from large hail with some tornadoes

possible. The 4 a.m. Sunday ZFP mentioned severe thunderstorms for Sunday night. At 

9:05 p.m. CDT May 4 WFO Memphis issued a HWO noting that the SPC had upgraded to a high

risk of severe weather with the main threat being tornadoes. Tornadoes were already occurring in

the area.

 Tornado Watch #239 was issued for the area at 6:55 p.m. May 4 mentioning, “this

is a particularly dangerous situation.” SPC also upgraded to a high risk of tornadoes at 8 p.m.

By 6:11 p.m., the first Severe Thunderstorm Warning was issued for Clay and Greene

counties in Arkansas. At 6:25 p.m. a Significant Weather Advisory (using the Special Weather

Statement header - SPS) was issued for Dunklin County in Missouri. By 7:06 p.m., the first

Tornado Warning was issued for Dunklin County. The last warning expired at 12:15 a.m. May

5. During the event, the Memphis WFO issued 36 Tornado Warnings, 20 Severe Thunderstorm

Warnings, 70 Severe Weather Statements, 2 Local Storm Reports, and 1 Significant Weather

Advisory. 

WFO Memphis worked well as a team during the event. Staffing levels were appropriate

to workload. The lead forecaster determined that additional staffing was needed and staff were
23

called in as the event began. Two amateur radio operators were also called and arrived by 7:20

p.m. The ITO, also a meteorologist, was the first to arrive and quickly took over a warning

position on a LINUX workstation. Even though WFO Memphis had four staff positions vacant

(including the WCM) during this event, staffing reached a maximum of 9 persons including the

SOO and IT. The Lead Forecaster assumed the role of a warning coordinator and monitored the

entire warning operation, as well as answered the telephone. The warning responsibilities were

split into two separate sector teams, each with two members. One member of the warning team

was responsible for performing radar interrogation and making warning decisions while the other

assisted in warning decisions, editing, and issuing the text warning products. One forecaster

handled public forecast responsibilities, SPC coordination and watch products. Another handled

the aviation forecasting duties. A team, consisting of an HMT and Data Acquisition Program

Manager (DAPM), monitored NOAA Weather Radio (NWR), answered the telephone, and

issued area wide Short Term Forecasts. Warnings were announced to the entire operations area

and automatically broadcast on NWR.

A constant flow of warnings and statements to the public and media was maintained by

the WFO during the event. On average, a product was issued approximately every 2.5 minutes. 

WFO Memphis had partially responded to Recommendation 4d (completed by 8/15/03) from the

Veteran’s Day Weekend Tornado Outbreak Service Assessment. 

March 2003 Recommendation WFO Memphis Actions on May 4

Regions should work with WFO

management to ensure issuance of SVSs

per directive 10-511 and LSRs per

Directive 10-517 are included in Severe

Weather Operations Plans and emphasized

in station drills. 

A total of 70 Severe Weather Statements and

2 Local Storm Reports were issued.

 

The media interviewed commented that they were pleased with the large number of

SVSs, but would like to have seen a constant flow of LSRs. The media mentioned a steady flow

of LSRs helps support their decision to go to full time coverage. 

There were, however, several issues associated with this event. Folded radar velocity

data was evident in the lower elevation slices from the Memphis WSR-88D as the F4 tornado

approached Jackson. The staff did not want to change the Pulse Repetition Frequency (PRF) to

eliminate the range folding for fear that it might adversely affect radar sampling of other storms 

(Recommendation 3). In this case, warnings operations did not appear to be affected.

Bandwidth to the associated Department of Defense (DOD) WSR-88D radar was also an

issue during these events. The data line from Columbus Air Force WSR-88D to WFO Memphis

had inadequate bandwidth on May 4 and 5, and suffered loadshedding of critical products,
24

including the 0.5 degree Storm Relative Motion (SRM) as a result. The 8-bit reflectivity and

velocity products now generated by the Open Radar Product Generator (ORPG) can not

consistently be sent to the WFOs connected to these radars because of bandwidth limitations

(Recommendation 4).

 

The CRS portion of NWR reported database errors after receiving a Severe

Thunderstorm

Warning product from WFO Little Rock, Arkansas at approximately 10:00 p.m. May 4.

Following the database errors, all Severe Thunderstorm Warnings had to be recorded manually.

Tornado Warnings and other products continued to be automatically broadcast on CRS. The

WFO self-diagnosed and fixed the database problem on the morning of May 5.

The WFO Memphis staff was prepared for this event. During the period March-May

2003 WFO Memphis completed procedural drills on severe weather and flash flooding, and two

WES training sessions, one of which was a supercell case from WFO Paducah, Kentucky.

Interviews of emergency management directors in Dyer County and Madison County,

(where the fatalities occurred) indicate WFO Memphis has maintained a close working

relationship with each. Dyer County has been recognized as StormReady and had hosted a

spotter training session in the fall of 2002, just prior to the severe weather season. 

In February 2003, a spotter training session was conducted in Jackson (Madison County)

sponsored by the Office of Emergency Management. Dan Vaughn, the Madison County’s

Assistant EM Director stated he has regular contact with WFO Memphis. He receives all the

warnings issued by the WFO via his pager. His first indication that a tornadic storm was

approaching May 4 was via the pager message that came from WFO Memphis. The county EM

director stated being StormReady, “definitely helped and likely saved lives.@ As the tornadoes

were approaching, they deployed their spotters and were able to get information even though the

NWR transmitter in Jackson was off the air as of 8:47 p.m. May 4, due to a power outage from a

previous tornado in Madison County, which affected the area before the Jackson tornado struck

at 11:23 p.m.

The director also stated he did not feel comfortable enough about the reliability of the

Jackson NWR site to stop relying on the county’s siren system to sound severe storm warnings

for the area. An interview with the Memphis MIC, however, indicated this NWR system had

undergone recent upgrades to its antenna and associated components and as a result, its

reliability had greatly improved.

WFO Memphis has a well established amateur radio SKYWARN severe weather spotter 

program. There are eight SKYWARN divisions across the CWA. A roster of net control

volunteers is maintained at the office and the amateur radio operators are called in during all

significant severe weather events. WFO Memphis trained 1478 spotters in FY 2002, and 758

spotters through May 2003.
25

Local media reported that it is a common practice for WFO Memphis to conduct a

briefing or press conference at the weather office prior to most significant severe weather

outbreaks or winter storms. However, the threat of severe weather on May 4 and 5 was not

apparent to the WFO Memphis forecasters early enough in advance to schedule a press

conference prior the event. 

Four of the major television stations covering the Memphis market area were

interviewed. In every contact, the local television meteorologist had high praise for the

performance of WFO Memphis the night of May 4 and into the morning of May 5. 

Brian Teigland, WPTY ABC 24, praised WFO Memphis for issuing Special Weather

Alerts during the event and the relationship between WFO Memphis and WPTY. 

“(WFO Memphis) did a good job of getting out Special Weather Alerts (SWAs...issued

under the SPS header)...it was a very thorough job.”

“We have a tremendous relationship with the Memphis office. I talk to Jim Duke (WFO

Memphis MIC) on a regular basis. We give them credit for their warnings and

complement them on the air.”

The station cut in live with the new SWA information and ran a severe weather message

across the screen. More than one TV station used the SWA information on the air. Most of the

television stations went with continuous live coverage about the time the first Dyersburg

Tornado Warning was issued at 7:57 p.m.

WBBJ ABC 7 is located in Jackson where there were 11 fatalities. Meteorologist 

Gary Pickens stated, “There was a good marriage between what they were putting out and what

we were seeing. It gave us the opportunity to project where the storm was going. I noticed that

they were able give up to 40 minutes of advanced notice, that’s great lead time. It gave

everyone a fighting chance to take cover and move to safety.”

 Jim Jaggers, WHBQ Fox 13, used the text from Tornado Watch Number 239 which

stated, “this is a particularly dangerous situation” to call the public=s attention to the

developing severe weather. Jim stated, “We have a great relationship with the Memphis

office...always have.”

Dave Brown, Chief Meteorologist for WMC NBC 5, echoed Jim Jaggers’ opinion about

their relationship with WFO Memphis, “I have had a partner relationship with WFO Memphis

for 26 years. They did as good a job as anyone could have expected. They made it easy for us.”

 A very successful means of communication initiated by WFO Memphis was an instant

messaging system. Typically, the system would be used to inform the media of an upcoming

severe warning, a change in a severe storm, or recent damage reports. The media uses the

system to relay damage reports to the WFO and ask questions of the forecasters. All of the area
26

television stations that were interviewed, mentioned the usefulness of the instant messaging

system and would like to see its use greatly expanded. 

New warnings are reformatted and sent out every five minutes from WFO Memphis to

computers in the office that are connected to area pager companies. This was a significant

source of information for emergency management directors of Madison County and Dyer

County. Both indicated it was the primary way they knew there was severe weather approaching

on May 4. 

Issues

Fact: Range folded Storm Relative Velocity data was evident in the lower elevation slices of

the Memphis WSR-88D during a portion of the event. 

Fact: The staff seemed reluctant to change the pulse repetition frequency (PRF) even though

the new Open Radar Product Generator (ORPG) has simplified this task. 

Finding 3: Storm Relative Velocity data from the WFO Memphis WSR-88D were not

optimized for warning operations.

Recommendation 3: WFO Memphis Operational Staff should review their training on

monitoring and adjusting radar sectors and PRFs to optimize velocity data for warning

operations. 

Fact: Frequent load shedding on the Columbus Air Force WSR-88D radar caused 0.5 degree

SRM data to be lost to WFO Memphis during the May 4 severe weather event. The WFO

effected a workaround, reducing the number of products on the Radar Product Set (RPS) list. 

Fact: The bandwidth between NWS and DOD radars is also inadequate to view 8 bit radar

data,

including Reflectivity and Storm Relative Motion. 

Finding 4: Bandwidth to associated DOD WSR-88D sites is inadequate to ensure a flow of

the required number and type of radar products, including 8 bit data, to enhance detection

of severe weather.

Recommendation 4: NWS should work with DOD to increase bandwidth between a WFO

and an associated WSR-88D. The connection should have sufficient bandwidth to assure

that radar products needed for severe weather detection (including 8-bit data) are

available to the warning forecasters.
27

E. WFO Paducah, Kentucky

Overview

 

A total of 21 tornadoes (1 F-4, 1 F-3, 1 F-2, 11 F-1s and 7 F-0s) were recorded across the

Paducah, Kentucky CWA during the evening of May 6 through early morning on May 7. The

strongest of these was a violent (F-4) tornado which moved through Pulaski, Massac, and Pope

Counties in extreme southern Illinois. This tornado was on the ground between 9:32 p.m. and

10:42 p.m. on May 6, creating a 33-mile continuous path length with an average width of 2/3 of

a mile. There were two fatalities from this tornado. Both fatalities occurred within the

boundaries of Tornado Watch 275 and the respective Tornado Warnings for Pulaski and Massac

Counties. 

Nineteen of the 21 tornadoes were covered by Tornado Warnings. One weak tornado

was covered by a Severe Thunderstorm Warning and there was another weak tornado that moved

across portions of Hickman and Graves Counties in Kentucky that was not in a warning. The

average lead time for counties in which a tornado occurred was 9 minutes and ranged from 0 to

37 minutes.

The Paducah WFO was included in the SPC’s Day 2 Outlook on May 4. The WFO began

to first emphasize the threat for severe weather in a HWO issued at 5:21 a.m., Monday, May 5. 

The HWO mentioned, “damaging winds...large hail...and a few tornadoes will be possible.”

The HWO issued at 5:05 a.m., Tuesday, May 6, indicated the area was included in SPC’s

Day 1 moderate risk area. The product stated, “Supercell storms with large hail...damaging

winds and the potential for tornadoes will be possible across southeast Missouri this

afternoon and evening. Damaging winds and large hail can be expected later as the storm

form a line.” 

The HWO was again updated at 5:41 p.m., Tuesday, May 6. The product was updated to

include Tornado Watch 275 issued at 5:40 p.m. for the entire WFO Paducah’s CWA. The

product mentioned a significant severe weather outbreak was expected. A Special Weather

Statement, issued shortly thereafter at 6:04 p.m., advised all to “Remain vigilant. Be prepared

to take quick action should severe weather be observed or a warning be issued.”

A 20-minute “Meet Me” conference call was initiated by the WCM around 7 p.m., 

May 6, to alert the WFO’s customers and partners. Two hours prior to the call, approximately

50 persons, including emergency managers, state police, and media, were contacted via cell

phone, pager, and e-mail with the use of “EM Notification” software. In addition, storm

spotters, emergency managers, etc., participating in a locally developed program known as “ESpotter” were notified. 

The WFO Paducah staff met briefly the morning of May 6 at 8 a.m. for both a weather

briefing and to assess staff availability. Additional staff were called in early in the event. 
28

The WFO Paducah Station Duty Manual (SDM) defined the roles for each position

during severe weather events. For an event where moderate to extensive severe weather is

expected, the staffing guidelines are to have 10 people on duty. For the event on May 6, staffing

ranged between 12 and 14, and included the MIC, SOO, WCM, and ESA. Due to staff

familiarization with roles as defined in the SDM, no one perceived any duplication of duties, yet

all felt the level of service provided would have been impossible with any lesser staffing.

In addition, two amateur radio net controllers reported to the WFO Paducah office at

8:30 p.m. Prior to the arrival of the net controller, the WCM, who is a licensed amateur radio

operator, had been monitoring, since 6 p.m., the Cape Girardeau, Missouri, amateur radio

repeater for communications describing storms approaching the Paducah WFO.

WFO Paducah issued 144 severe weather products between 7:44 p.m., May 6, and 

1:28 a.m., May 7. There were 40 Tornado Warnings, 45 Severe Thunderstorm Warnings, 36

Local Storm Reports, and 23 Severe Weather Statements. 

 There were some significant communications issues at WFO Paducah during this event.

At approximately 10:54 p.m. CDT, the AWIPS frame-relay circuits for WFO Paducah failed.

AWIPS Network Control Facility (NCF) was notified at 10:58 p.m. and worked quickly to

reestablish a backup connect via a 56-kbps dial connection at 11 p.m. CDT. This dial backup

circuit was used until 5:27 a..m., May 7. The telephone company’s trouble ticket indicated the

outage was caused by a power problem at their Pulaski, Illinois, facility.

Four high-priority severe weather products sent from Paducah were delayed more than

60 seconds. All four appear to have been sent during the outage. The products were as follows:

S Tornado Warning for Ballard County Kentucky took 5 minutes and 24 seconds to

reach NCF

S Severe Weather Statement took 5 minutes and 11 seconds

S Preliminary Local Storm Report took 3 minutes and 19 seconds

S Tornado Warning for Pope County Illinois took 1 minute and 2 seconds

When the AWIPS frame-relay network fails, dial backup can take several minutes to

implement. There is no alarm at the local office that the primary AWIPS frame-relay has failed 

(Recommendation 5).

After dial backup was initiated, it became apparent that the 56 kbps bandwidth was

insufficient to transmit lower priority products, such as radar data from three associated 

WSR-88Ds and Internet traffic, in a timely manner. Radar data reaching NCF were delayed by

times ranging from 16 minutes to 2 hours, 45 minutes from 11:16 p.m., May 6 through 
29

6:07 a.m. May 7. Connectivity with the Central Region Internet web server was also disrupted. 

This also delayed communication for Internet-based applications such as E-Spotter

(Recommendation 6). 

WFO Paducah utilized E-Spotter extensively during the event to receive and provide

critical information. This software also allowed for the rapid sharing and heightened

seriousness (“extremely dangerous situation”) simultaneously relayed to multiple emergency

managers for the deadly F4 tornado. 

WFO Paducah had extensive coordination during the event with local and state officials. 

One example of this coordination was the repeated contact with the Illinois State Police Post in

Ullin, Illinois. Accurate forecasts were provided to the post of where the F4 tornado could

potentially cross Interstate 24. Contact with Metropolis, Illinois 9-1-1 Communication

Dispatcher led to the movement of Massac County firemen away from the tornado to a safe

shelter. 

A late winter/early spring staff training program at WFO Paducah had just concluded

prior to the week of May 4. As part of this program, each forecaster completed at least two WES

cases. One case was on high precipitation supercells intersecting a boundary which produced a

tornado in April 2002 in the Paducah CWA. The second case was from WFO Des Moines, Iowa

on April 11, 2001, that included mini-supercells producing multiple tornadoes. Additional

training encompassed various COMET (Cooperative Program for Operational Meteorology,

Education, and Training) modules and webcast seminars. Severe Weather seminars earlier in the

year reviewed the April 2002 tornado case. A full staff Severe Weather Roundtable Session was

held in February 2003. This dedicated session included discussion of total office operations

during severe weather.

The following WFO Paducah special teams were key contributors to the overall readiness

of this event: the WFO Paducah Tornado Team (responsible for post-event assessments), the

WFO Paducah Quick Response Verification Team (responsible for calling individuals and

businesses for storm reports), and the WFO Paducah Storm Damage Survey Team (responsible

for field surveys of storm damage). All of these team members had gone through early 2003

spring meetings to review procedures and mission goals. 

 WFO Paducah accomplished an aggressive 2003 SKYWARN spotter training campaign.

From January through March 2003, 48 SKYWARN spotter training seminars were taught by a

team of eight WFO Paducah staff instructors. In addition, the Paducah WCM and MIC have been

very active in working with counties and communities in the Storm Ready program. WFO

Paducah’s SOO also developed a specialized radar training course for emergency managers that

has been frequently requested.

The WFO Paducah staff is active in preparedness and outreach events. Numerous public,

emergency management, and media workshops and outreach activities were noted by the service

assessment team. 
30

The WFO Paducah staff received a number of positive comments from both EMs and

media:

Keith Davis, Massac County, Illinois, 9-1-1 Coordinator, stated, “Based on the

warning phone call you (the NWS) made to his cell phone, a number of firemen were able

to make it to safe shelter near Round Knob just before the second (tornadic) storm got to

them. Needless to say, they are very, very grateful to you (the NWS) for making that

extra call.”

Justin Gibbs, SKYWARN Coordinator at Murray State University in Calloway County,

 Kentucky, “It happened again and you all still nailed it. As always, you all handled a

very dangerous situation well. Impeccable work on the (Massac) event, the northern

Graves damage, and our damage here. We really appreciated having the amateur radio

operator in there, and having us well informed on E-spotter.”

A recorded telephone message to WFO Paducah’s WCM , “I just wanted to tell the

Paducah staff that they saved some people’s lives out here tonight. We were not looking

especially for that second storm. We lost all power and lost pretty much everything but

the NOAA weather radios. Tell your people they did a phenomenal, phenomenal job

tonight and we are very much appreciative down here in Calloway County.” 

Through their Weather Information Now (WIN) telephone tree, WFO Paducah keeps an

open telephone to the public 24 hours a day, seven days a week. This service provides direct

access to a staff member any time a need arises. During this tornado outbreak, 3 to 4 staff

members staffed the phones at all times. This communication outlet served to pass on vital

information to the general public. The Local Emergency Planning Committee from Henderson

County Kentucky said, 

“Thank you for your immediate telephone availability, so we can talk to a person. This

also gives us the opportunity to ask quick questions and get immediate response and

answers. Keep up the good work on communications!!”

The Paducah Sun Newspaper featured a front page article on May 11, 2003, that focused

 on “what it’s like to work at the National Weather Service” when an ongoing event of this

magnitude occurs. “Controlled Chaos” was the descriptive term used to begin the article. It was

then quickly defined by staff members that qualified it by, “Everybody knew what their job was

and they did it.” 

Issues

Fact: On May 6, 2003, at approximately 10:54 p.m. CDT, the AWIPS frame-relay circuits for

WFO Paducah failed. Connectivity was reestablished by NCF (AWIPS Network Control

Facility) on a 56 kbps dial connection by about 11:00 p.m. CDT. This dial backup circuit was
31

used until 5:27 a.m. on May 7, 2003. The phone company’s trouble ticket indicated the outage

was caused by a power problem at their Pulaski, Illinois facility.

Fact: AWIPS met applicable requirements for high priority message availability during this

event. 

Fact: The NCF operator’s performance was exemplary in restoring WFO Paducah’s connectivity

within two minutes of receiving the IT Operations (ITO) alarm from the site, even though the

alarm arrived four minutes after the actual frame relay outage occurred. 

Fact: Four high-priority severe weather products sent from WFO Paducah, including Tornado

Warnings, were delayed on the AWIPS WAN from 62 seconds to 5 minutes, 24 seconds due to

the failure. The products were not delayed for other methods of dissemination such as NOAA

Weather Radio. 

Fact: When the AWIPS frame-relay network fails, dial backup can take several minutes for

NCF to implement. 

Fact: There is no alarm at the local office that the AWIPS frame relay line has failed.

Finding 5: Time needed to send critical severe weather products was lost during this failure

of the frame-relay circuit. 

Recommendation 5a: NWS should assure the AWIPS software notifies the WFO

operations staff that a frame relay circuit failure has occurred and dial backup has been

implemented.

 

Recommendation 5b: NWS should develop methods to reduce the amount of elapsed time

between a frame relay outage and when this outage generates an IT Operations (ITO)

alarm at the NCF operator’s console.

Fact: The 56 kbps dial backup to the AWIPS frame-relay network is used to transmit lower

priority products including radar images. 

Fact: Radar data reaching NCF was delayed in excess of 16 minutes from 11:16 p.m. CDT 

May 6 through 6:07 a.m. May 7 due to the limited bandwidth of the dial backup line. The

peak delay reached was 2 hours 45 minutes. 

Fact: Media and Emergency Managers rely on timely radar images via the Radar Product

Central Collection Dissemination Service (RPCCDS) to make timely decisions or

provide information for their communities. 

Finding 6: The 56K bandwidth currently used by the NWS for frame-relay backup is

inadequate in situations such as severe weather outbreaks. In these instances, multiple
32

radars may be sending images to the RPCCDS, and critical partners and customers depend

on timely receipt of these images. 

Recommendation 6: The Office of Science and Technology (OS and T) should re-evaluate

bandwidth requirements for AWIPS dial backup or determine other ways to reduce delays

in customer receipt of radar and other critical data. 

This two-story home in western Massac County, Illinois suffered F4 damage. The remnants

of the upper floor are seen in the distance.

F. WFO Norman, Oklahoma

Overview

During the five day period between May 6 and May 10, the CWA of WFO 

Norman, Oklahoma was impacted by an extended period of severe weather. The WFO

experienced severe weather in its CWA every day, including tornadoes on May 7, 8, and 9.

By far, the most significant day was May 8 and this day will be the primary focus of this
33

 section. On May 8, a violent (F4) tornado swept across Moore and south Oklahoma City along a

19 mile path. The tornado injured 135 and caused significant damage to a General Motors

assembly plant and Tinker Air Force Base. There was a 21 minute lead time for the Tornado

Warning on this storm and it produced no fatalities. The tornado produced $110,000,000

damage. Two other tornadoes, both F0 intensity, struck south Oklahoma City, and Red Rock (in

northern Oklahoma) with no injuries or fatalities and only tree damage reported. All 3 tornadoes

were covered by Tornado Warnings. Average lead time was 17 minutes, with a range from 15 to

21 minutes.

May 9 was also a significant severe weather day as seven tornadoes moved across

southwest and central Oklahoma. The most significant was a strong (F3) tornado that moved

through northwest Oklahoma City along an 18 mile path. This tornado caused 10 minor injuries

and no direct fatalities. There was a 41 minute lead time for the Tornado Warning on this storm.

All seven tornadoes (1 F-3, 4 F-1s and 2 F-0S) were covered by Tornado Warnings. The

tornadoes had an average lead time of 38 minutes, with a range from 26 to 45 minutes. The

tornadoes produced $10,000,000 damage. 

Services Before and During May 8 event

Severe weather awareness in this area was already elevated by recent severe weather and

by the anniversary of the May 3, 1999 F5 tornado which killed over 40 people in Grady County,

Moore and south Oklahoma City. The Moore and south Oklahoma City area were again affected

by the May 8 event.

The WFO recognized early on May 8 that severe weather was likely. The 7:00 a.m.

Hazardous Weather Outlook (HWO) noted the SPC slight risk covering the area, and mentioned

“The most likely time...will be from mid afternoon through late tonight.” The HWO also

urged storm spotter groups and emergency management officials to plan for severe weather

operations “...from around 3 p.m. through this evening.” The WFO updated the HWO at

noon, upgrading the severe risk from slight to moderate, and mentioning the “...risk of a few

tornadoes.”

At 1:35 p.m., the SPC issued Tornado Watch #304 including much of WFO Norman’s

CWA. By 2:26 p.m., the first storms began to appear on radar, and the WFO began issuing

experimental Warning Decision Updates, discussing the potential for severe weather in the

developing cells. At 2:30 p.m., the WFO conducted a live NOAA Weather Radio (NWR)

briefing on all of their transmitters, discussing the likelihood of severe weather. Extra staffing

was made available. Frequent Regional Weather Discussions, Warning Decision Updates and

Significant Weather Advisories were issued as storms continued to develop. The HWO was

updated at 3:40 p.m. to include a high risk, including the Oklahoma City metropolitan area.

From the time of the first Tornado Warning in Grady County at 4:33 p.m., until the last

Tornado Warning expired at 6:45 p.m., the WFO issued a total of 60 products, including 5

Tornado Warnings, 3 Severe Thunderstorm Warnings, 24 Severe Weather Statements, 6 Local
34

Storm Reports, 9 Significant Weather Alerts, 8 Warning Decision Updates, and 5 Regional

Weather Discussions. (The Significant Weather Alerts and Regional Weather Discussions are

experimental products). In addition, live NWR coverage was provided from 5:13 p.m. through

6:00 p.m. 

Throughout the day, the WFO website included experimental graphics depicting the

increasing threat of severe weather and likely time and area of development. 

The thunderstorm which spawned the F4 tornado was first identified in a Warning

Decision Update at 3:45 p.m. This was followed by several intervening update products. A

Severe Thunderstorm Warning was issued for Grady County at 4:09 p.m., and was upgraded to a

Tornado Warning at 4:33 p.m. While this initial warning was not verified, it did heighten

awareness for the next downstream counties, McClain and Cleveland, which mark the beginning

of the Oklahoma City metro area.

The WFO issued a Tornado Warning for McClain County, Cleveland County and

southern portions of Oklahoma County at 4:49 p.m., specifically mentioning the city of Moore in

Cleveland County. It was in Moore the first reports came in of a tornado touching down near

state Highway 37 and Western Avenue at 5:10 p.m. Upon receiving this report, the WFO went

to Alive@ coverage on the Oklahoma City NWR for the duration of the event, providing near realtime information from spotters via amateur radio and telephone reports. The WCM provided

live broadcasts on NWR. The tornado continued through Oklahoma County, striking a General

Motors plant and Tinker Air Force Base, and finally lifted near Choctaw in eastern portions of

the county at 5:40 p.m. A second storm produced a brief F0 tornado in Red Rock in northern

Oklahoma with no injuries and only damage to trees. 

There were eleven operational staff members working during the event, including the

MIC, SOO, and WCM. There were two routine product forecasters, 2 warning forecasters

utilizing a sectorized warning approach, two warning coordinators (the MIC and SOO), and one

forecaster dedicated to writing Significant Weather Advisories as a Aheads-up@ for downstream

counties. There were also 3 public service personnel to collect data and handle phone calls.

Services Before and During the May 9 event

The May 9 morning Hazardous Weather Outlook mentioned SPC=s moderate risk of

severe weather from late afternoon Friday through early Saturday morning, and specifically

mentioned that A...tornadoes will also be possible.” SPC issued Tornado Watch #320 for central

Oklahoma at 3:35 p.m., valid until 9:00 p.m.

The WFO had been issuing warnings for storms in the north Texas part of their CWA

throughout the day. During the afternoon, severe storms producing large hail developed in

central and southwest Oklahoma, including the Oklahoma City metro area, and continued into

the evening hours. WFO products were plentiful in number, frequency and variety. Throughout
36

the 16 hour event, a total of 211 products were issued, including 61 Severe Weather Statements,

38 Local Storm Reports, 38 Severe Thunderstorm Warnings, 29 Significant Weather Advisories,

16 Warning Decision Updates and 13 Tornado Warnings. Live NWR broadcasts were also done

from 10:00 PM to 11:30 PM as the storms moved across the Oklahoma City metro area. 

 Staffing during the event was comparable to that on May 8, with as many as 12

operational meteorological staff on duty, including the MIC, SOO, and WCM. Three sectors of

warning operations were utilized to provide greater focus on individual storm systems.

Information common to both events

 Staff interviewed expressed concern with regard to the performance of the AWIPS HP

 workstation to keep up with a rapidly developing event in multiple locations. At least one

forecaster had to revert to manually editing Severe Weather Statements to maintain a constant

flow of products. (The AWIPS workstation upgrades being implemented nationwide will address

this performance concern.) During both events, the WFO provided constant live coverage on the

Oklahoma City NWR transmitter. These live broadcasts provided a constant flow of the latest

information from all available sources, including WSR-88D and Terminal Doppler Weather

Radar (TDWR), storm spotters, then media, and other sources. At the same time, traditional text

products, such as the Severe Weather Statement were still being issued frequently

(Recommendation 7). 

With a history of repeated tornado strikes (the most recent being the May 3, 1999 F5

 tornado in virtually the same location as as the tornado on May 8), the Oklahoma City

population is well aware of the threats tornadoes pose to their area. The WFO outreach efforts

capitalize on this built-in awareness, and the emergency management and media outlets surveyed

indicate considerable effort on the part of the WFO to build and maintain relationships and assist

in education and outreach efforts. One emergency manager stated that he is in contact with the

WFO WCM A...at least every other week.@ 

Feedback from the emergency management community at the state, county and local

levels was unanimously positive. All individuals contacted indicated that they were briefed 

“well in advance” of the actual event, and were fully aware that a dangerous situation existed.

All expressed great confidence in the local WFO staff and specifically mentioned that they

considered the local WFO as their most valuable source of real-time weather information.

Oklahoma emergency managers have efficient access to real-time NWS radar and forecast

information through an Internet decision support system.

The following items were specifically mentioned by the emergency management

personnel as being especially valuable:

- Proactive coordination and communication efforts to provide a two-way flow of

information
37

- Experimental graphics posted on the Internet

- Timely post-event evaluations and information, especially on the Internet

- Numerous, timely, short and to the point Severe Weather Statements 

Gayland Kitch, The Emergency Management Director in Moore, whose community has

been struck by tornadoes on October 4 , 1998, May 3, 1999, and May 8, 2003 said, “Thanks

once again for having made possible over the years a tremendously strong program of weather

support for the emergency managers of the state of Oklahoma, and also in providing the training

for us to properly use the products.”

The quote below, from Oklahoma Governor Brad Henry, illustrates how well customers

perceived services and products from WFO Norman during the event. 

“They (NWS) did such a tremendous job of giving early warning to the residents of

Oklahoma about these storms in such a manner that it enabled people to seek

appropriate shelter. I believe that was a major factor contributing to the fact that we had

only one (indirect) fatality, and frankly, minimal serious injuries.” 

Service Assessment team members interviewed two televison meteorologists, one from 

KOCO and one from KWTV in Oklahoma City. Both of them said they have excellent rapport

with staff at both the NOAA SPC and the WFO in Norman. During both events, broadcasters

provided continuous coverage featuring updated warnings and forecasts from the NWS as well

as reports from their storm spotters who were chasing the tornadoes. Broadcasters were in

unison in their accolade that the ANWS warnings were excellent, timely, and the forecasts were

out there in advance.@ Broadcasters said they agreed with the urgent tone of the Tornado

Warning issued May 9 as an F3 tornado moved across northwest portions of the Oklahoma City

metro area. 

The WCM sent a note to broadcast meteorologists on May 8 informing them that the

NWS would be experimenting with a new product, the Warning Decision Update. Reactions

include:

“Both products are excellent. OKC guys probably didn’t get to monitor the warning

decision bulletins, but I followed them closely and they were right on...giving critical

information. I got to use them last night, and again an awesome product. Regional

weather discussions are well appreciated, especially from spotters.” 

Andy Wallace, KSWO. 

“It was like they knew in advance what was going to happen!” Rick Mitchell, 

KOCO-TV
37

“We found the Warning Decision Update useful on Thursday and Friday. It was nice to

read what you guys were thinking, and to get a heads up on the potential for warnings. It

was also helpful to read about things that you were noticing that we may have

overlooked. All in all, I found this product very useful, and I hope it will continue.”

Frank Johnson, KOCO-TV 

Service Assessment team members interviewed 26 people in Moore about the

May 8 tornado. Everyone in this sample group acknowledged awareness of the possibility of

severe weather in the area as early as the previous day and said they remember hearing media

reports of impending severe weather the morning of their events. 

Issues

Fact: Severe Weather Statements were not individually broadcast on NWR during live

programming. 

Finding 7: Severe weather reports received from phone, amateur radio, and other sources

for inclusion in Severe Weather Statements were simultaneously broadcast during live

NWR programming, thus speeding the process of disseminating critical information to the 

public.

Recommendation 7: WFO Norman station instructions should assure that the information

from Severe Weather Statements, and other pertinent information from other sources, be

included in the live NWR broadcasts to speed the dissemination of fast changing

information.
38

The General Motors Manufacturing Plant in southeast Oklahoma City after the May 8

tornado. 

G. Issues Common to All Five WFOs

Since most WFOs are issuing numerous LSRs during severe weather outbreaks, a

common request from the media was a summary LSR be issued shortly after the event ends.

Since so many LSRs are issued during major events, they felt it would possible to miss some

reports (Recommendation 8).
39

 The public and the media continue to increase use of the Internet for information such as

forecasts and data such as radar data. For the period May 4 through 10, Southern Region web

server computers recorded an average of over 22.5 million hits per day (a hit is defined as an

object downloaded from a web page), Central Region recorded an average of over 16.5 million

hits per day and SPC alone had an average of 5.6 million hits per day. Since there is high

demand on Internet resources during major severe weather outbreaks, Central Region

Headquarters has set up a priority username and password system for emergency managers to

obtain the most timely radar data.FF

Figure 9. Number of “hits” on web servers (in millions) for Southern Region Headquarters,

Central Region Headquarters and the Storm Prediction Center during the period May 4-10, 2003. 

All of the WFOs and the SPC posted information including maps of storm surveys and

tornado damage images to their pages after their respective events. Many favorable comments

were received by the service assessment team with regard to information posted on the

WFO’s/SPC Web Page. However, some WFOs began to post information as soon as 2 to 3 hours

after the event, while one WFO did not post any information until 4 days after their outbreak. 

May 4 May 5 May 6 May 7 May 8 May 9 May 10

0

5

10

15

20

25

30

35

Southern Region Central Region

Storm Prediction Center

Internet Hits Per Day
The regions should encourage WFOs to, as resources permit, quickly post storm information on

their web pages (Recommendation 9). 

Issues

Fact: Most WFOs issued numerous real-time LSRs during their tornado outbreaks.

Fact: A frequent media request during interviews was for summary LSRs to be issued at the end

of the event.

Fact: There is no requirement in NWS Directive 10-517 for summary LSRs at the end of major

weather events. 

Finding 8: Since real-time LSRs may be numerous during severe weather outbreaks, the

media and emergency mangers need a summary LSR issued at the end of the event. This

summary will recount all LSRs issued during the event. 

Recommendation 8: NWS Directive 10-517 should be revised to require summary LSRs

shortly after the end of a major severe weather outbreak.

Fact: Media and emergency managers interviewed praised both the WFOs and the SPC for

information posted to web pages. The most used information included text forecasts, graphical

forecasts, and storm survey and damage images.

Fact: SPC and all WFOs posted information concerning their respective outbreaks on their web

pages.

Fact: Some WFOs posted information concerning their respective outbreaks several hours after

the event, while others posted no information until 4 days after the event. 

Finding 9: WFOs should place priority on timely posting of storm information on their web

pages, including damage surveys and storm damage images after major events. 

Recommendation 9: The Regions should work with all WFOs to emphasize the value of

quickly placing post-storm information on their Internet web pages for their respective

media, emergency managers, and the public. 

40
41

Best Practices

Improved Services to Customers and Partners

1. WFO Memphis, Tennessee utilized instant messaging and paging to notify partners of

impending severe weather.

2. WFO Paducah, Kentucky and Pleasant Hill, Missouri used a notification system called

“E-Spotter” to alert spotters and emergency managers of severe weather potential.

3. WFOs Pleasant Hill and Springfield, Missouri and Norman, Oklahoma routinely stop and

restart their AWIPS workstations before an outbreak of severe weather, to help assure

adequate workstation performance. The WFO Pleasant Hill ITO did a complete restart of

all workstations prior to their May 4 outbreak.

4. WFO Springfield, Pleasant Hill, and Paducah utilized conference calls with emergency

managers to alert them of the severe weather threat well in advance.

5. WFO Pleasant Hill mapped out their severe weather position utilization plan in advance.

The warning coordinator for the event assigned “flash cards” to each person during the

event with clearly defined duties for each position. 

6. WFO Norman conducted a live severe weather briefing on NOAA Weather Radio.

7. Central Region Headquarters staff members were dispatched to WFO Pleasant Hill to

augment staffing during their May 4 severe weather event, and assisted office operations

in the days after the event. 
1

 From J. Atmos. Sci., August 1981, p. 1517-1519.

A-1

Appendix A

Fujita Tornado Intensity Scale1

The Fujita Tornado Intensity Scale is a scale of wind damage intensity which wind speeds are

inferred from an analysis of wind damage.

Tornadoes are rated using the Fujita Tornado Intensity Scale or F-scale, named after the late

Dr. T. Theodore Fujita, former professor of Meteorology, University of Chicago. The F-scale is a

subjective visual interpretation used by the NWS to rate the worst building damage anywhere along the

path from 0 to 5, with 5 being the most destructive. Empirically-derived wind speed ranges are also

associated with the F-scale. An accurate F-scale rating is important for historical, statistical, and

climatological reasons and allows the public to get a sense of the storm’s destructive force.

Category Definition and Effect

F0 Gale tornado (40-72 mph): Light damage. Some damage to chimneys; break

branches off trees; push over shallow-rooted trees; damage sign boards.

F1 Moderate tornado (73-112 mph): Moderate damage. The lower limit is the

beginning of hurricane wind speed; peel surface off roofs; mobile home pushed off

foundations or overturned; moving autos pushed off the roads.

F2 Significant tornado (113-157 mph): Considerable damage. Roofs torn off frame

houses; mobile homes demolished; boxcars pushed over; large trees snapped or

uprooted; light-object missiles generated.

F3 Severe tornado (158-206 mph): Severe damage. Roofs and some walls torn off

well-constructed houses; trains overturned; most trees in forest uprooted; heavy cars

lifted off ground and thrown.

F4 Devastating tornado (207-260 mph): Devastating damage. Well-constructed

houses leveled; structure with weak foundation blown off some distance; cars thrown

and large missiles generated.

F5 Incredible tornado (261-318 mph): Incredible damage. Strong frame houses lifted

off foundations and carried considerable distance to disintegrate; automobile-sized

missiles fly through the air in excess of 100 yards; trees debarked; steel-reinforced

structures badly damaged; incredible phenomena will occur.
B-1

Appendix B

Direct Fatalities in Each WFO’s CWA

WFO Pleasant Hill - May 4 

No. Age Gender Location Circumstances

1 81 M Kansas City, Ks. Heading for Shelter

WFO Springfield - May 4 

No. Age Gender Location Circumstances

1 50 F Cherokee County, Ks.

4N/2W Galena

At home. Thrown 500 feet from

home.

2 80 M Cherokee County, Ks

near Badger

In frame home which was destroyed

3 73 F Cherokee County, Ks

near Badger

In frame home which was destroyed

4 48 F Crawford County, Ks

Ringo

In mobile home

5 68 M Crawford County, Ks.

Ringo

In mobile home

6 87 F Crawford County, Ks.

Franklin

In frame home 

7 40 F Greene County, Mo

Battlefield

Outdoors

8 53 M Camden County, Mo

5 SW Camdenton

In mobile home

9 75 M Camden County, Mo

6 S Camdenton

At home

10 76 F Camden County, Mo

6 S Camdenton

At home
B-2

11 70 M Jasper County, Mo.

Carl Junction

In frame home. 

12 62 F Jasper County, Mo

Carl Junction

In frame home

13 63 F Christian County, Mo

4.5 N Clever

In frame home

14 88 M Barton County, Mo

2 W Liberal

In frame home, on way to basement

15 52 F Lawrence County, Mo.

Marionville

Modular home

16 39 F Lawrence County, Mo.

1 N Marionville

Mobile home

17 20

wks

M Lawrence County, Mo

2 N Monett

In mobile home

18 46 F Lawrence County, Mo

2 N Monett 

In mobile home

19 Unk M Lawrence County, Mo

Pierce City

In field house

20 40 M Cedar County, Mo

Stockton

In frame home

21 34 M Cedar County, Mo

Stockton

Outdoors

22 86 M Cedar County, Mo

Stockton

Handicapped, could not get to

basement

23 49 M Dallas County, Mo

Urbana

In modular home

24 47 M Dallas County, Mo

Urbana

In modular home

25 83 F Camden County, Mo

4 NNW Decaturville

In frame home
B-2

11 70 M Jasper County, Mo.

Carl Junction

In frame home. 

12 62 F Jasper County, Mo

Carl Junction

In frame home

13 63 F Christian County, Mo

4.5 N Clever

In frame home

14 88 M Barton County, Mo

2 W Liberal

In frame home, on way to basement

15 52 F Lawrence County, Mo.

Marionville

Modular home

16 39 F Lawrence County, Mo.

1 N Marionville

Mobile home

17 20

wks

M Lawrence County, Mo

2 N Monett

In mobile home

18 46 F Lawrence County, Mo

2 N Monett 

In mobile home

19 Unk M Lawrence County, Mo

Pierce City

In field house

20 40 M Cedar County, Mo

Stockton

In frame home

21 34 M Cedar County, Mo

Stockton

Outdoors

22 86 M Cedar County, Mo

Stockton

Handicapped, could not get to

basement

23 49 M Dallas County, Mo

Urbana

In modular home

24 47 M Dallas County, Mo

Urbana

In modular home

25 83 F Camden County, Mo

4 NNW Decaturville

In frame home
B-3

WFO Memphis

No. Age Gender Location Circumstances

1 31 F Rural Madison County, Tn. In mobile home

2 34 M Rural Madison County, Tn. In mobile home

3 8 M Rural Madison County, Tn. In mobile home

4 40 F Rural Madison County, Tn. In mobile home

5 39 M Rural Madison County, Tn. In mobile home

6 44 F Rural Madison County, Tn. In mobile home

7 23 F Rural Madison County, Tn. In mobile home

8 7 M Rural Madison County, Tn. In mobile home

9 53 M Rural Madison County, Tn. Found in street, was visiting a

mobile home in area

10 22 F Jackson Apartment building

11 1 M Jackson Apartment building

WFO Paducah

No. Age Gender Location Circumstances

1 65 F Massac County, Il

NW of Joppa

In mobile home

2 53 M Pulaski County, Il

Grand Chain

In home

WFO Norman - May 8/9

None
C-1

Appendix C

Event Statistics

WFO Kansas City, Missouri (EAX)

May 4, 2003

# Tornadoes 9

# Tornado Warnings 23

Average Lead Time for Tornado Warnings 24 minutes

# Severe Thunderstorm Warnings 21

Fatalities 1

Injuries 43

Homes Destroyed 223

Homes Damaged 1103

Damage Costs ~$143 million

WFO Springfield, Missouri (SGF)

May 4, 2003

# Tornadoes 15

# Tornado Warnings 33

Average Lead Time for Tornado Warnings 23 minutes

# Severe Thunderstorm Warnings 25

Fatalities 25

Injuries 143

Homes Destroyed 1143

Homes Damaged 2024

Damage Costs ~$159 million
C-2

WFO Memphis, Tennessee (MEG)

May 4, 2003

# Tornadoes 18

# Tornado Warnings 34

Average Lead Time for Tornado Warnings 20

# Severe Thunderstorm Warnings 20

Fatalities 11

Injuries 70

Homes Destroyed 353

Homes Damaged 4834

Damage Costs $100,000,000

WFO Paducah, Kentucky (PAH)

May 6, 2003

# Tornadoes 21 

# Tornado Warnings 40

Average Lead Time for Tornado Warnings 9

# Severe Thunderstorm Warnings 32

Fatalities 2 

Injuries 38

Homes Destroyed 205

Homes Damaged 453

Damage Costs $27,000,000
C-3

WFO Norman, Oklahoma (OUN)

May 8, 2003

# Tornadoes 3

# Tornado Warnings 5

Average Lead Time for Tornado Warnings 17

# Severe Thunderstorm Warnings 3

Fatalities 0

Injuries 135

Homes Destroyed 375

Homes Damaged 1923

Damage Costs ~$110 million

WFO Norman, Oklahoma (OUN)

May 9, 2003

# Tornadoes 7 

# Tornado Warnings 13

Average Lead Time for Tornado Warnings 38 

# Severe Thunderstorm Warnings 38 

Fatalities 0

Injuries 7

Homes Destroyed 57

Homes Damaged 930

Damage Costs ~$10 million