An upper-level disturbance pushed into west-central Illinois during the afternoon of August 20th, triggering widespread showers and thunderstorms. Due to a very moist airmass and relatively slow storm motion, locally heavy rainfall of between 1 and 3 inches occurred.
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 ILX wrote it up.
An upper-level disturbance pushed into west-central Illinois during the afternoon of August 20th, triggering widespread showers and thunderstorms. Due to a very moist airmass and relatively slow storm motion, locally heavy rainfall of between 1 and 3 inches occurred. Minor flooding was reported in many typically flood-prone locations. One fatality occurred in Springfield when a woman fell partially into a manhole as she was attempting to push her car out of a flooded viaduct. Several of the thunderstorms produced gusty winds, with one cell downing numerous tree branches in Morgan County.
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 Lincoln, IL wrote its last area forecast discussion before the first event at Aug 20, 12:47 PM CST, 4 hours 23 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 147 PM CDT FRI AUG 20 2010 .DISCUSSION... ISSUED 130 PM CDT FRI AUG 20 2010 SCATTERED THUNDERSTORMS DEVELOPED ACROSS PARTS OF EAST CENTRAL MISSOURI EARLIER THIS MORNING AND WERE TRACKING NE INTO PARTS OF WEST CENTRAL ILLINOIS THIS AFTERNOON AHEAD OF A WEAK SHORTWAVE ACRS CNTRL MO. A SECOND UPPER LEVEL WAVE NOTED ACRS THE MISSOURI VALLEY WILL BRING A COLD FRONT INTO OUR AREA LATE TNT INTO SATURDAY MRNG. MORE ORGANIZED CONVECTION IS EXPECTED ALONG THIS FRONTAL BOUNDARY OVERNIGHT INTO SATURDAY. THE BETTER INSTABILITY ON THE 17Z SPC MESOANALYSIS WAS NOTED OVER WESTERN IL WITH MIXED LAYER CAPES OF 2500 TO 3000 J/KG. EARLY AFTN TEMPERATURES WERE ALREADY INTO THE UPPER 80S FAR WEST TO THE MIDDLE 90S FAR SOUTHEAST. SHORT TERM...TONIGHT THROUGH MONDAY NIGHT MAIN FORECAST CONCERN THIS PERIOD WILL BE COVERAGE OF THUNDERSTORMS ACRS THE FORECAST AREA OVERNIGHT INTO SATURDAY...FOLLOWED BY TEMPS AND HUMIDITIY LEVELS SUNDAY AND INTO EARLY NEXT WEEK. NO REAL SIG MODEL DIFFERENCES SEEN SO WL TREND MORE TWDS THE HIGH RES WRF MODEL WITH RESPECT TO THE TIMING OF THE FROPA AND CONVECTION CHANCES OVERNIGHT INTO SATURDAY. ALL MODELS SHOWING PWAT VALUES OF +2.3 INCHES OVERNIGHT INTO SATURDAY MRNG AHEAD OF THE COLD FRONT WITH FORECAST SOUNDINGS SHOWING SOME RATHER IMPRESSIVE WARM CLOUD DEPTHS OF GREATER THAN 13000 FEET ACRS WESTERN IL FOR A TIME LATE THIS EVENING. RAINFALL RATES OF 1 TO 2 INCHES PER HOUR WILL BE LIKELY WITH SOME OF THE STRONGER STORMS...BUT COVERAGE OVER OUR AREA TONIGHT IS STILL A CONCERN. 4KM SPC WRF SUGGESTS THE ORGANIZED CONVECTION MAY TEND TO SPLIT...WITH ONE AREA SHIFTING ACRS OUR NW...WHILE A SECOND BAND OF STORMS SHIFTS SHARPLY TO THE SE TOWARDS THE HIGHER INSTABILITY AXIS OVER NE MO THRU SOUTHWEST IL. OPERATIONAL GFS AND HI-RES 4KM SPC MODELS ALL HINT AT AN MCV PUSHING ACRS THE AREA OVERNIGHT INTO SATURDAY MRNG. FLASH FLOOD GUID VALUES OF 2.5 TO 3 INCHES OVER MOST OF THE FCST AREA SO AT THIS POINT...WL HOLD OFF ANY FLOOD HEADLINES ACRS THE WEST WHERE SOME OF THE HIGHER QPF VALUES WILL OCCUR. STORMS WILL BE ONGOING SATURDAY MORNING AHEAD OF THE WEAK COLD FRONT WHICH SHOULD PUSH INTO SE IL BY 00Z SUNDAY. BEST CHANCES OF RAIN OVERNIGHT INTO SATURDAY MRNG ACRS THE WEST AND CENTRAL PORTIONS OF THE FORECAST AREA WILL SHIFT INTO THE EAST AND SOUTHEAST DURING THE DAY. STILL A QUESTION AS TO WHETHER CONVECTION WILL REFIRE DURING THE AFTN AHEAD OF THE COLD FRONT AND MCV ACRS EAST CENTRAL AND SOUTHEAST ILLINOIS. SHOWER AND THUNDERSTORM CHANCES WILL START TO SHIFT INTO EXTREME SOUTHEAST ILLINOIS SATURDAY EVENING AND THEN TRACK TO THE EAST OF THE AREA OVERNIGHT AS HIGH PRESSURE SLOWLY BUILDS SE INTO THE REGION. MODELS CONTINUE TO ADVERTISE UPPER LEVEL RIDGING BUILDING NE INTO THE MIDWEST SUNDAY AND INTO EARLY NEXT WEEK BRINGING WARM AND DRY WEATHER THROUGH MONDAY NIGHT. LONG TERM...TUESDAY THROUGH FRIDAY AMPLIFIED UPPER LEVEL RIDGE WILL BE SHORT-LIVED ACRS THE MIDWEST AS A FAIRLY POTENT UPPER LEVEL SHORTWAVE PUSHES ACRS THE NRN PLAINS ON TUESDAY. THIS SHOULD ALLOW A COLD FRONT TO TRACK EWD INTO THE REGION DURING THE DAY TUESDAY. DEEPER TROPICAL MOISTURE WILL HAVE BEEN SHUNTED TO OUR EAST AND SOUTH SATURDAY NIGHT ALONG THE COLD FRONT SO NOT A GREAT DEAL OF MOISTURE ASSOCIATED WITH THE TUESDAY WAVE IN ADDITION TO THE BEST FORCING BEING WELL TO OUR NORTH...SO HAVE OPTED TO KEEP THE FORECAST DRY FOR NOW AND SEE HOW MODELS TREND IN THE NEXT SEVERAL DAYS. AFTER TUESDAY...SEASONABLY WARM WEATHER IS EXPECTED TO CONTINUE ALONG WITH LITTLE IN THE WAY OF RAINFALL. SMITH && .AVIATION... ISSUED 1218 PM CDT FRI AUG 20 2010 CLUSTER OF SHOWERS AND STORMS BETWEEN KUIN-KSTL MOVING NORTHEAST BUT BECOMING LESS ORGANIZED. AWIPS TIME-OF-ARRIVAL TOOL WOULD SUGGEST THEM ARRIVING AT KSPI TOWARD 20Z IF THEY HOLD ON THAT LONG. OTHER SCATTERED STORMS IN WESTERN ILLINOIS WARRANT CONTINUING THE VCTS AT KPIA AS WELL. OTHERWISE...MAIN PROBLEM PERIOD WILL BE AFTER 00Z AS ADDITIONAL SHOWERS/STORMS FORM ALONG A COLD FRONT AND PUSH ACROSS ILLINOIS. WILL UPDATE THE TIMING REFLECTED IN THE PREVIOUS TAF ISSUANCE...SLOWING IT DOWN ACROSS AREAS NEAR KDEC/KCMI...WHERE IT WILL LIKELY LINGER LONGER AFTER 12Z AS A RESULT. FORECAST SOUNDINGS INDICATE MVFR CONDITIONS LIKELY IMMEDIATELY FOLLOWING THE FRONTAL PASSAGE SATURDAY MORNING...BEFORE LIFTING TOWARD THE END OF THE FORECAST PERIOD. GEELHART && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LINCOLN IL 308 PM CDT FRI AUG 20 2010 ILZ027>031-036-037-040-041-047-211200- CASS-FULTON-KNOX-MARSHALL-MASON-PEORIA-SCHUYLER-STARK-TAZEWELL- WOODFORD- 308 PM CDT FRI AUG 20 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL ILLINOIS. .DAY ONE...TONIGHT SCATTERED THUNDERSTORMS WILL BE LIKELY THROUGH THE OVERNIGHT HOURS. A FEW OF THE STORMS MAY BE SEVERE THROUGH 800 PM CDT...WITH THE MAIN SEVERE WEATHER THREAT BEING DAMAGING WINDS THIS EVENING. IN ADDITION...TORRENTIAL RAINFALL WILL BE LIKELY WITH A FEW OF THE STRONGER STORMS...WITH HOURLY RAINFALL RATES OF UP TO 2 INCHES IN A FEW LOCATIONS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY LINGERING SHOWERS AND A FEW THUNDERSTORMS WILL BE POSSIBLE FOR THE FIRST HALF OF THE DAY SATURDAY...BUT NO SEVERE STORMS ARE EXPECTED. QUIET WEATHER WILL THEN DOMINATE FOR THE REMAINDER OF THE PERIOD. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL BE NEEDED THROUGH 800 PM CDT. ILZ038-042-043-048>053-211200- CHRISTIAN-DE WITT-LOGAN-MACON-MCLEAN-MENARD-MORGAN-SANGAMON-SCOTT- 308 PM CDT FRI AUG 20 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL ILLINOIS. .DAY ONE...TONIGHT SCATTERED THUNDERSTORMS WILL BE LIKELY TONIGHT. HOWEVER...THE THREAT FOR SEVERE STORMS WILL BE LOW. THE STRONGER STORMS MAY PRODUCE GUSTY WINDS AND VERY HEAVY RAINFALL THROUGH THE OVERNIGHT HOURS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO AT LEAST THE FIRST HALF OF SATURDAY. THE THREAT FOR SEVERE STORMS WILL AGAIN BE LOW... HOWEVER...HEAVY RAIN WILL BE POSSIBLE WITH SOME OF THE MORE INTENSE STORMS. QUIET WEATHER WILL THEN DOMINATE FOR THE REMAINDER OF THE PERIOD. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED THROUGH TONIGHT. ILZ044>046-054>057-061>063-066>068-071>073-211200- CHAMPAIGN-CLARK-CLAY-COLES-CRAWFORD-CUMBERLAND-DOUGLAS-EDGAR- EFFINGHAM-JASPER-LAWRENCE-MOULTRIE-PIATT-RICHLAND-SHELBY- VERMILION- 308 PM CDT FRI AUG 20 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL ILLINOIS...EAST CENTRAL ILLINOIS AND SOUTHEAST ILLINOIS. .DAY ONE...TONIGHT THUNDERSTORMS WILL BE LIKELY LATE TONIGHT...HOWEVER THE THREAT FOR SEVERE STORMS WILL BE LOW. THE STRONGER STORMS MAY PRODUCE VERY HEAVY RAINFALL. THE PRECIPITATION IS FORECAST TO CONTINUE THROUGH THE OVERNIGHT HOURS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH SATURDAY. DURING THE AFTERNOON HOURS...SOME OF THE STRONGER STORMS MAY PRODUCE GUSTY WINDS AND VERY HEAVY RAIN ALTHOUGH THE THREAT FOR SEVERE STORMS WILL BE LOW. THE PRECIPITATION IS FORECAST TO MOVE EAST OF THE AREA SATURDAY EVENING...THEN QUIET WEATHER WILL DOMINATE FOR THE REMAINDER OF THE PERIOD. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED THROUGH TONIGHT. SMITH
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
218 PM CDT FRI AUG 20 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0203 PM HEAVY RAIN GALESBURG 40.95N 90.38W
08/20/2010 M1.40 INCH KNOX IL TRAINED SPOTTER
RAINFALL IN 45 MINUTES. MINOR STREET FLOODING.
&&
JANKOWSKIPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
256 PM CDT FRI AUG 20 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0245 PM HEAVY RAIN GALESBURG 40.95N 90.38W
08/20/2010 M2.60 INCH KNOX IL TRAINED SPOTTER
RAINFALL SINCE 1PM.
&&
JANKOWSKIPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
317 PM CDT FRI AUG 20 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0258 PM HEAVY RAIN ABINGDON 40.80N 90.40W
08/20/2010 M2.28 INCH KNOX IL MESONET
RAINFALL IN ABOUT AN HOUR.
&&
JANKOWSKISPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LINCOLN IL
535 PM CDT FRI AUG 20 2010
ILZ040-202300-
SCHUYLER-
535 PM CDT FRI AUG 20 2010
...SIGNIFICANT WEATHER ALERT FOR SCHUYLER COUNTY UNTIL 600 PM CDT...
AT 532 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 8 MILES NORTHWEST OF
GOLDEN TO MOUNT STERLING...MOVING NORTHEAST AT 40 MPH.
WINDS AROUND 50 MPH ARE EXPECTED WITH THESE STORMS.
PEOPLE IN SCHUYLER COUNTY...INCLUDING THE CITIES OF BROOKLYN...
RUSHVILLE AND LITTLETON...SHOULD MONITOR THE WEATHER SITUATION
CLOSELY. LISTEN FOR POSSIBLE WARNINGS...AND BE PREPARED TO TAKE
APPROPRIATE ACTION SHOULD SEVERE WEATHER THREATEN.
A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 8 PM.
LAT...LON 4028 9092 4028 9046 4015 9046 4000 9061
4001 9062 4002 9062 4002 9065 4004 9069
4007 9068 4008 9071 4010 9071 4010 9086
4011 9093
TIME...MOT...LOC 2235Z 223DEG 35KT 4023 9109 4004 9080
GEELHARTPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
602 PM CDT FRI AUG 20 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0558 PM HEAVY RAIN GILSON 40.87N 90.20W
08/20/2010 M2.41 INCH KNOX IL MESONET
RAINFALL SO FAR TODAY. SWOP.
&&
JANKOWSKIPRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE LINCOLN IL
603 PM CDT FRI AUG 20 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0203 PM HEAVY RAIN GALESBURG 40.95N 90.38W
08/20/2010 M1.40 INCH KNOX IL TRAINED SPOTTER
RAINFALL IN 45 MINUTES. MINOR STREET FLOODING.
0209 PM HEAVY RAIN ABINGDON 40.80N 90.40W
08/20/2010 E1.50 INCH KNOX IL MESONET
RAINFALL IN ABOUT 40 MINUTES. SWOP.
0245 PM HEAVY RAIN GALESBURG 40.95N 90.38W
08/20/2010 M2.60 INCH KNOX IL TRAINED SPOTTER
RAINFALL SINCE 1PM.
0258 PM HEAVY RAIN ABINGDON 40.80N 90.40W
08/20/2010 M2.28 INCH KNOX IL MESONET
RAINFALL IN ABOUT AN HOUR.
0558 PM HEAVY RAIN GILSON 40.87N 90.20W
08/20/2010 M2.41 INCH KNOX IL MESONET
RAINFALL SO FAR TODAY. SWOP.
&&
JANKOWSKIThe Lincoln radar (KILX), 89 km away, was scanning. The volume nearest the first event began at 23:08 UTC.
1 thunderstorm wind, 1 flood. Local standard time, as filed.
Numerous tree limbs were blown down across Jacksonville. A tree was snapped at the trunk and fell onto Hoagland Boulevard. A large window at a bridal shop was broken and several homes lost shingles from their roofs.
A woman drowned in downtown Springfield near the intersection of 3rd and Capitol after her car stalled in an underpass which was flooded due to a storm sewer backup. As she was trying to push her car out of about three feet of standing water, she slipped partially into a manhole cover and was submerged. The area had received 1.52 of rain, with 1.41 falling during the two hours prior to the drowning. Minor flooding of typically flood-prone areas was reported elsehwere around Springfield.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Flood, Sangamon | 2010-08-20 | 23 | Female | Vehicle/Towed Trailer | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2010Every state in 2010This day in weather historyWarnings in Illinois, August 2010
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: 258076, 266437.