A mesoscale convective system developed along a cold front that extended from Ohio southwest across southern Illinois to southern Missouri. The storms produced very heavy rain and isolated strong wind gusts.
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 PAH wrote it up.
A mesoscale convective system developed along a cold front that extended from Ohio southwest across southern Illinois to southern Missouri. The storms produced very heavy rain and isolated strong wind gusts.
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 Paducah, KY wrote its last area forecast discussion before the first event at Aug 20, 10:52 PM CST, 3 hours 8 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PADUCAH KY 1152 PM CDT SAT AUG 20 2011 .UPDATE... UPDATED FOR THE 06Z TAF ISSUANCE. && .DISCUSSION... AM CONVECTION IS ABOUT OVER..WITH ONLY ISOLATED/LINGERING LIGHT SHOWER ACTIVITY. UPSTREAM...SEE COMING TOGETHER OF NEXT PCPN CHANCE...WHICH WILL OCCUR TONIGHT...AS COLD FRONT MAKES APPROACH AND PASSAGE. MAINTAINED INHERITED LIKELY POPS. THESE POPS MAY LINGER IN OUR EASTERN ZONES THRU EARLY SUNDAY...DID MAKE THAT MODIFICATION ACCORDINGLY. POST FRONTAL AIRMASS IS THEN SLIGHTLY COOLER/DRIER...AND SHOULD CONTINUE INTO/THRU EARLY WEEK. UPPER TROF PASSAGE ON TUE-WED RE-INTRODUCES SMALL PCPN CHANCE...AFTER WHICH REMAINDER OF FORECAST RETURNS DRY AGAIN. TEMPS INHERITED WERE GOOD AND ONLY SLIGHTLY MODIFIED PER NEWEST DATA/COLLABORATIVE BLENDS. && .AVIATION... A WEAK COLD FRONT WILL MOVE SOUTHEAST ACROSS THE TAF SITES TONIGHT THROUGH EARLY SUNDAY MORNING. THUNDER CHANCES WILL INCREASE WITH THE PASSAGE OF THE FRONT. COULD SEE MVFR CONDITIONS IN TSRA...THEN FOLLOWING THE FRONTAL PASSAGE...EXPECT VFR CONDITIONS SUNDAY MORNING WITH LIGHT NORTHWEST WINDS. && .PAH WATCHES/WARNINGS/ADVISORIES... KY...NONE. MO...NONE. IL...NONE. IN...NONE. && JAP/RJP
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PADUCAH KY 1001 PM CDT SAT AUG 20 2011 ILZ075>078-080>094-INZ081-082-085>088-KYZ001>022-MOZ076-086-087- 100-107>112-114-211015- JEFFERSON-WAYNE IL-EDWARDS-WABASH-PERRY IL-FRANKLIN-HAMILTON- WHITE-JACKSON-WILLIAMSON-SALINE-GALLATIN-UNION IL-JOHNSON-POPE- HARDIN-ALEXANDER-PULASKI-MASSAC-GIBSON-PIKE-POSEY-VANDERBURGH- WARRICK-SPENCER-FULTON-HICKMAN-CARLISLE-BALLARD-MCCRACKEN-GRAVES- LIVINGSTON-MARSHALL-CALLOWAY-CRITTENDEN-LYON-TRIGG-CALDWELL- UNION KY-WEBSTER-HOPKINS-CHRISTIAN-HENDERSON-DAVIESS-MCLEAN- MUHLENBERG-TODD-PERRY MO-BOLLINGER-CAPE GIRARDEAU-WAYNE MO-CARTER- RIPLEY-BUTLER-STODDARD-SCOTT-MISSISSIPPI-NEW MADRID- 1001 PM CDT SAT AUG 20 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHERN ILLINOIS...SOUTHWEST INDIANA...WESTERN KENTUCKY AND SOUTHEAST MISSOURI. .DAY ONE...TONIGHT ISOLATED TO SCATTERED THUNDERSTORMS REMAIN POSSIBLE TONIGHT INTO SUNDAY MORNING...AS A COLD FRONT MOVES THROUGH. SEVERE WEATHER IS NOT ANTICIPATED...BUT LOCALLY HEAVY RAIN WILL BE POSSIBLE WITH THE HEAVIER DOWNPOURS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY A FEW THUNDERSTORMS WILL BE POSSIBLE FROM LATER IN THE DAY TUESDAY THROUGH MUCH OF THE WEEK. HOWEVER...SEVERE STORMS SHOULD BE ISOLATED AT BEST. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED.
The Paducah radar (KPAH), 50 km away, was scanning. The volume nearest the first event began at 08:00 UTC.
1 heavy rain, 1 thunderstorm wind. Local standard time, as filed.
A storm-total rainfall of 3.1 inches was reported by the general public. A two-mile stretch of a rural county road was washed out but passable.
Large tree limbs at least three inches in diameter were blown down. Underpinning was blown off mobile homes.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2011Every state in 2011This day in weather historyWarnings in Illinois, August 2011
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: 332055, 332054.