Strong thunderstorms developed across Northern Missouri during the afternoon hours and crossed over a warm front in Northeast Missouri. A lone supercell thunderstorm became elevated after it crossed the warm front and moved across Clark County in Missouri, Lee County in Iowa, and Hancock and McDonough Counties in Illinois.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS DVN wrote it up.
Strong thunderstorms developed across Northern Missouri during the afternoon hours and crossed over a warm front in Northeast Missouri. A lone supercell thunderstorm became elevated after it crossed the warm front and moved across Clark County in Missouri, Lee County in Iowa, and Hancock and McDonough Counties in Illinois. Rotational velocity with the mesocyclone was 60 knots (69 mph) off of KLSX 88D in Clark County but storm surveys indicated only straight line wind damage of 43 to 52 knots (50 to 60 mph) with localized winds of 65 knots (75 mph) across Clark, Lee, Hancock, and McDonough counties. Surveys did indicate a continuous line of straight line wind damage from the north side of Keokuk, Iowa, northeast across the Mississippi River to between Ferris and Adrian in Illinois.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Quad Cities, IA wrote its last area forecast discussion before the first event at May 24, 12:50 PM CST, 6 hours 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 150 PM CDT MON MAY 24 2004 .DISCUSSION... THE PRIMARY CONCERN TODAY IS THE REAL THREAT OF SIGNIFICANT SEVERE WEATHER AND RIVER/FLASH FLOODING TONIGHT. LATEST SURFACE ANALYSIS SHOWS STRONG LOW PRESSURE OVER SOUTHEAST NEBRASKA...WITH A STRONG WARM FRONT EXTENDING SOUTHEAST THROUGH MISSOURI AND SOUTHERN ILLINOIS. THIS FRONT HAS STALLED AND IS NOW LIFTING NORTH OVER WESTERN MISSOURI. PRESSURE FALLS OVER EASTERN IOWA AND NORTHWEST ILLINOIS SHOW THAT WARM ADVECTION HAS BEGUN. STRONGER PRESSURE FALLS OF NEARLY 6MB ARE FOUND OVER WESTERN IOWA AS OF 18Z. THIS IS ASSOCIATED WITH INTENSE ELEVATED CONVECTION ALONG THE MISSOURI RIVER. OF GREATER CONCERN IS A MAXIMUM OF INSTABILITY OVER NORTHEAST KANSAS AND SOUTHEAST NEBRASKA...WHERE A COUPLE OF CELLS OF IGNITED IN THE PAST 20 MINUTES. THIS MAY BE THE BEGINNING OF A SEVERE MCS WHICH WILL TRACK OVER THE AREA TONIGHT. WE CONTINUE TO SEE AREAS SOUTH OF INTERSTATE 80 IN HIGH RISK BY SPC...PRIMARILY FOR HIGH WINDS AND TORNADIC STORMS (WHICH WILL BE MOST LIKELY NEAR THE WARM FRONT AND IN COMMA-HEAD VORTICIES IN BOW ECHO SEGMENTS.) THE AREA MOST AT RISK FOR THIS ACTIVITY WILL BE ALONG AND SOUTH OF HIGHWAY 34 IN IOWA...ILLINOIS AND NORTHEAST MISSOURI LATER THIS EVENING. A SECONDARY BUT SIGNIFICANT THREAT WILL BE HEAVY RAIN...WHICH IS LIKELY OVER ALL OF THE AREA. A DECENT SHORT WAVE...WILL HELP DRAW A LARGE STRATIFORM HEAVY RAIN SHIELD NORTH OF THE MAIN SEVERE CONVECTION THIS EVENING...THIS SHOULD IMPACT THE ENTIRE CWA AT SOME POINT THIS EVENING...THEREFORE HIGH POPS AND A FLOOD WATCH WILL BE CARRIED THROUGH THE TONIGHT PERIOD. AFTER PLENTY OF COORDINATION WITH OFFICES AND RFC...WE WILL BE ISSUING RIVER FORECAST PRODUCTS/FLOOD PRODUCTS SHORTLY. ADDITIONAL STORMS MAY BE POSSIBLE OVER SOUTHEAST SECTION TOMORROW AS THE FRONT MOVES AWAY FROM THE AREA...WILL GO LOW ON POPS AS GOOD SUBSIDENCE IS LIKELY BEHIND TONIGHTS STORMS. THE REMAINDER OF THE FORECAST IS LARGELY UNCHANGED. THE REGION WILL DRY OUT TUESDAY THROUGH THURSDAY AS HIGH PRESSURE UNDER ZONAL UPPER FLOW BUILDS INTO THE MIDWEST. BEYOND...A CUT OFF WEAKENING LOW IS EXPECTED TO LIFT NORTHEAST OVER THE AREA FRIDAY. MAY NEED POPS FOR THIS...AND WILL THROW IN POPS FRIDAY NIGHT FOR LLJ ACTIVITY. SATURDAY THROUGH MONDAY A STRONG AND SLOW MOVING TROUGH WILL BUILDING INTO THE ROCKIES. SEEMS LIKE WEVE SEEN THIS BEFORE WILL KEEP THUNDERSTORM CHANCES GOING SAT-MON. HEAVY RAIN...SEVERE WILL AGAIN BE A DAILY THREAT. ...ERVIN... && .DVN WATCHES/WARNINGS/ADVISORIES... IA...FLOOD WATCH TONIGHT. IL...FLOOD WATCH TONIGHT. MO...FLOOD WATCH TONIGHT. && ERVIN
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE QUAD CITIES IA IL 140 PM CDT MON MAY 24 2004 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-251100- BENTON IA-BUCHANAN IA-BUREAU IL-CARROLL IL-CEDAR IA-CLARK MO- CLINTON IA-DELAWARE IA-DES MOINES IA-DUBUQUE IA-HANCOCK IL- HENDERSON IL-HENRY IA-HENRY IL-IOWA IA-JACKSON IA-JEFFERSON IA- JO DAVIESS IL-JOHNSON IA-JONES IA-KEOKUK IA-LEE IA-LINN IA-LOUISA IA- MCDONOUGH IL-MERCER IL-MUSCATINE IA-PUTNAM IL-ROCK ISLAND IL- SCOTLAND MO-SCOTT IA-STEPHENSON IL-VAN BUREN IA-WARREN IL- WASHINGTON IA-WHITESIDE IL- 140 PM CDT MON MAY 24 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST IOWA... EAST CENTRAL IOWA...SOUTHEAST IOWA...NORTHWEST ILLINOIS...NORTH CENTRAL ILLINOIS...WEST CENTRAL ILLINOIS AND NORTHEAST MISSOURI. .DAY ONE...THIS AFTERNOON AND TONIGHT ...HIGH RISK FOR SEVERE WEATHER TONIGHT... A POTENTIALLY DANGEROUS WEATHER SITUATION IS SETTING UP FOR MUCH OF THE OUTLOOK AREA FOR LATE THIS AFTERNOON AND OVERNIGHT. THE AREA OF HIGH RISK IS SOUTH OF INTERSTATE 80 WITH A SLIGHT TO MODERATE RISK FOR AREAS TO THE NORTH. A LINE OF SEVERE THUNDERSTORMS WITH LARGE HAIL AND HIGH WINDS... POSSIBLY WITH EMBEDDED SUPERCELL THUNDERSTORMS AND TORNADOES...ARE EXPECTED TO DEVELOP OR MOVE INTO SOUTHEAST IOWA AND FAR NORTHEAST MISSOURI ALONG AN APPROACHING WARM FRONT LATE THIS AFTERNOON. THE THREAT WILL THEN EXTEND INTO WEST CENTRAL ILLINOIS IN THE EVENING. ALONG AND NORTH OF INTERSTATE 80...THUNDERSTORMS MAY DEVELOP WITH THE POTENTIAL TO PRODUCE HEAVY RAINFALL AND LARGE HAIL. OVERNIGHT...THE MAIN THREAT FROM ANOTHER ROUND OF THUNDERSTORMS WILL BE HEAVY RAINFALL...WITH A SMALLER RISK OF LARGE HAIL AND DAMAGING WIND. A FLOOD WATCH IS IN EFFECT FOR THE ENTIRE OUTLOOK AREA TONIGHT. ANY ADDITIONAL HEAVY RAINFALL TONIGHT WILL AGGRAVATE SIGNIFICANT RIVER FLOODING ALREADY OCCURRING OR FORECAST ACROSS THE AREA AND MAY ALSO LEAD TO FLASH FLOODING WHERE THE GROUND IS SATURATED FROM RECENT RAIN. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY A STORM SYSTEM WILL MOVE OUT OF THE SOUTHERN PLAINS INTO THE MIDWEST OVER THE WEEKEND. IT WILL BRING A THREAT OF SEVERE WEATHER TO THE AREA POSSIBLY ON SATURDAY...BUT MORE LIKELY SUNDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL BE NEEDED LATE THIS AFTERNOON AND TONIGHT FOR BOTH SEVERE WEATHER AND RAINFALL REPORTS. SHEETS
PRELIMINARY LOCAL STORM REPORT ... CORRECTION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
228 PM CDT MON MAY 24 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
1110 PM TSTM WND DMG SAVANNA 42.09N 90.14W
05/21/2004 CARROLL IL LAW ENFORCEMENT
TWO FOOT DIAMETER TREES DOWNED.
&&
JEBPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
238 PM CDT MON MAY 24 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
1159 PM HAIL 1 S WARREN 42.48N 89.99W
05/22/2004 1.00 INCH JO DAVIESS IL PUBLIC
DELAYED REPORT
&&
JEBPRELIMINARY LOCAL STORM REPORT ... CORRECTION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
302 PM CDT MON MAY 24 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0659 AM FLASH FLOOD MANCHESTER 42.49N 91.46W
05/23/2004 DELAWARE IA LAW ENFORCEMENT
SANDBAGGING HAS BEGUN.
0659 AM FLASH FLOOD BACKBONE STATE PARK 42.62N 91.55W
05/23/2004 DELAWARE IA LAW ENFORCEMENT
EVACUATING CAMPERS FROM PARK.
0830 AM FLASH FLOOD CEDAR RAPIDS 41.97N 91.67W
05/22/2004 LINN IA PUBLIC
DELAYED REPORT. CREEKS OUT OF BANKS.
1006 PM FLASH FLOOD 1 E STANLEY 42.64N 91.81W
05/21/2004 BUCHANAN IA EMERGENCY MNGR
ROAD AND BRIDGE WASHED OUT NEAR QUINN AND 100 STREET.
0530 PM FLASH FLOOD 4 E MARTELLE 42.02N 91.28W
05/21/2004 JONES IA PUBLIC
CREEKS OUT OF BANKS. DELAYED REPORT.
0530 PM FLASH FLOOD MARION 42.03N 91.59W
05/21/2004 LINN IA AIRPLANE PILOT
DELAYED REPORT. INDIAN CREEK OVERFLOWED ITS
BANKS...FLOODING A FOOTBALL FIELD AND STRANDING 4
STUDENTS.
&&
ALL REPORTS ARE DELAYED. SOME ARE CORRECTED TIMES.
JEBThe national radar mosaic for the moment the first event began.
2 thunderstorm wind. Local standard time, as filed.
Windows blown out of a house with numerous 8 inch limbs down.
Numerous 6 inch trees down.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Missouri in 2004Every state in 2004This day in weather historyWarnings in Missouri, May 2004
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5416178, 5416179.