Widespread showers and thunderstorms occurred along a nearly stationary frontal boundary extending from Iowa northeastward into the southern Great Lakes. An outflow boundary from this convection served as the focus for scattered thunderstorms across central Illinois during the afternoon of July 21st.
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.
Widespread showers and thunderstorms occurred along a nearly stationary frontal boundary extending from Iowa northeastward into the southern Great Lakes. An outflow boundary from this convection served as the focus for scattered thunderstorms across central Illinois during the afternoon of July 21st. The most concentrated area of storms developed from Lincoln eastward to the Indiana border. Numerous funnel clouds were reported, and one tornado briefly touched down in Vermilion 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 Jul 21, 11:21 AM CST, 1 hour 3 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1221 PM CDT WED JUL 21 2010 .DISCUSSION... ISSUED 1015 AM CDT WED JUL 21 2010 SYNOPTIC BOUNDARY APPEARS TO BE IN THE GENERAL VICINITY OF I-80 IN NORTHERN ILLINOIS LATE THIS MORNING...EXTENDING SOUTHWEST ACROSS FAR SOUTHERN IOWA. HAD A FEW SHOWERS/STORMS EARLIER TRACKING ACROSS NORTHERN PORTIONS OF THE CWA...AND CURRENTLY LINGERING AROUND CHAMPAIGN AND DANVILLE. ALSO HAVE SOME SCATTERED STORMS FROM CENTRAL MISSOURI INTO SOUTHEAST ILLINOIS JUST SOUTH OF OUR CWA...APPARENTLY ALONG AN OLD OUTFLOW BOUNDARY THAT ARCS ACROSS THIS REGION. MAIN QUESTION TODAY INVOLVES RENEWED SHOWER/STORM DEVELOPMENT. CONFIDENCE IN THE MODELS IS STILL RELATIVELY LOW...IN TERMS OF THE EXACT PLACEMENT OF ANY CONVECTIVE INITIATION. 12Z RUC/NAM MODELS SUGGEST A SOUTHWARD DRIFT IN THE SYNOPTIC BOUNDARY CLOSER TO THE NORTHERN CWA...WITH DECENT INSTABILITY SOUTH OF THE FRONT AND A WEAKENING CAP. THE RESIDUAL BOUNDARIES AND AN MCV MOVING EAST OUT OF THE CENTRAL PLAINS MAY HELP TO TRIGGER A FEW MORE STORMS THIS AFTERNOON. ZONES/GRID UPDATE FROM ABOUT 15 MINUTES AGO WAS MAINLY TO TWEAK THE HOURLY GRID ELEMENTS. GEELHART && .AVIATION... ISSUED 1220 PM CDT WED JUL 21 2010 CONVECTION BEGINNING TO FIRE AGAIN GENERALLY IN BETWEEN THE TAF SITES. AM EXPECTING A LITTLE BETTER COVERAGE AROUND KPIA/KSPI AROUND 20Z OR SO AS STORMS CURRENTLY NEAR THE MISSISSIPPI RIVER MOVE EAST...SO WILL INCLUDE TEMPO PERIODS AT THESE TWO SITES AND ONLY VCTS ELSEWHERE. LONGER RANGE...A FRONTAL BOUNDARY SHOULD SERVE AS THE FOCUS FOR SOME MORE THUNDERSTORM DEVELOPMENT IN THE 05-10Z TIME FRAME...BEFORE THE FRONT BEGINS TO LIFT NORTHWARD. BESIDES THE CONVECTIVE CHANCES...THE PERSISTENT LIGHT AND VARIABLE WIND PATTERN SHOULD BECOME MORE OF A STEADY SOUTH WIND AFTER SUNRISE...ONCE THE FRONT IS NORTH OF THE AREA. GEELHART && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LINCOLN IL 1127 AM CDT WED JUL 21 2010 ILZ027>031-037-038-221100- KNOX-MARSHALL-MCLEAN-PEORIA-STARK-TAZEWELL-WOODFORD- 1127 AM CDT WED JUL 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL ILLINOIS. .DAY ONE...THIS AFTERNOON AND TONIGHT SCATTERED THUNDERSTORMS WILL BE POSSIBLE ACROSS THE AREA THIS AFTERNOON AND EVENING...DUE TO A STATIONARY FRONT IN NORTHERN ILLINOIS...AND A RESIDUAL OUTFLOW BOUNDARY ACROSS MISSOURI. THERE IS A SLIGHT RISK THAT THESE STORMS WILL BECOME SEVERE...WITH DAMAGING WIND GUSTS THE PRIMARY CONCERN. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE WITH SOME OF THE STRONGER STORMS. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THUNDERSTORMS ARE EXPECTED ON THURSDAY..AS THE FRONTAL BOUNDARY GRADUALLY SHIFTS NORTHWARD ACROSS THE AREA. ANY STORMS THAT OCCUR WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL AND POSSIBLY SOME DAMAGING WINDS. AFTER A SHORT BREAK...THUNDERSTORMS WILL BE POSSIBLE AGAIN LATE FRIDAY AND SATURDAY AS A COLD FRONT SLOWLY APPROACHES THE AREA FROM THE NORTHWEST. HEAT INDEX VALUES ARE EXPECTED TO BE AROUND 100 DEGREES FRIDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND EVENING...PRIMARILY THROUGH SUNSET. ILZ036-040-041-047-049-050-221100- CASS-FULTON-MASON-MORGAN-SCHUYLER-SCOTT- 1127 AM CDT WED JUL 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WEST CENTRAL ILLINOIS. .DAY ONE...THIS AFTERNOON AND TONIGHT SCATTERED THUNDERSTORMS WILL BE POSSIBLE THIS AFTERNOON AND EVENING...DUE TO A RESIDUAL OUTFLOW BOUNDARY ACROSS MISSOURI AND SOUTHERN ILLINOIS. THERE IS A SLIGHT RISK THAT THESE STORMS WILL BECOME SEVERE...WITH DAMAGING WINDS THE PRIMARY THREAT. A FEW OF THE STRONGER STORMS WILL ALSO BE CAPABLE OF PRODUCING AND HEAVY RAINFALL. AS A WARM FRONT APPROACHES TONIGHT...BETTER COVERAGE OF THUNDERSTORMS IS EXPECTED. THE PRIMARY THREAT TONIGHT FROM THE THUNDERSTORMS WILL BE FROM HEAVY RAINFALL AND GUSTY WINDS. MINOR FLOODING IS EXPECTED ALONG PORTIONS OF THE ILLINOIS RIVER...PERSISTING INTO THE WEEKEND. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY ADDITIONAL THUNDERSTORMS WILL BE POSSIBLE THURSDAY...AS THE WARM FRONT SHIFTS NORTH OF THE AREA. ANY STORMS THAT OCCUR WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL AND POSSIBLY SOME DAMAGING WINDS. RUN OFF FROM THIS RAINFALL WILL LEAD TO SIGNIFICANT RISES ON MANY AREA CREEKS AND STREAMS. AFTER A PERIOD OF QUIET WEATHER...THUNDERSTORMS WILL BE POSSIBLE AGAIN ON SATURDAY AS A COLD FRONT APPROACHES FROM THE NORTHWEST. HEAT INDEX VALUES ARE EXPECTED TO BE AROUND 100 DEGREES THURSDAY... AND FROM 100 TO 105 DEGREES FRIDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND EVENING...PRIMARILY THROUGH SUNSET. ILZ042>046-048-051>057-061>063-221100- CHAMPAIGN-CHRISTIAN-CLARK-COLES-CUMBERLAND-DE WITT-DOUGLAS-EDGAR- LOGAN-MACON-MENARD-MOULTRIE-PIATT-SANGAMON-SHELBY-VERMILION- 1127 AM CDT WED JUL 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL ILLINOIS AND EAST CENTRAL ILLINOIS. .DAY ONE...THIS AFTERNOON AND TONIGHT SCATTERED THUNDERSTORMS WILL BE POSSIBLE THIS AFTERNOON AND EVENING...DUE TO A RESIDUAL OUTFLOW BOUNDARY ACROSS MISSOURI AND SOUTHERN ILLINOIS. THERE IS A SLIGHT RISK THAT THESE STORMS WILL BECOME SEVERE...WITH DAMAGING WINDS THE PRIMARY THREAT. A FEW OF THE STRONGER STORMS WILL ALSO BE CAPABLE OF PRODUCING AND HEAVY RAINFALL. AS A WARM FRONT APPROACHES TONIGHT...BETTER COVERAGE OF THUNDERSTORMS IS EXPECTED. THE PRIMARY THREAT TONIGHT FROM THE THUNDERSTORMS WILL BE FROM HEAVY RAINFALL AND GUSTY WINDS. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY ADDITIONAL THUNDERSTORMS WILL BE POSSIBLE THURSDAY...AS THE WARM FRONT SHIFTS NORTH OF THE AREA. ANY STORMS THAT OCCUR WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL AND POSSIBLY SOME DAMAGING WINDS. RUN OFF FROM THIS RAINFALL WILL LEAD TO SIGNIFICANT RISES ON MANY AREA CREEKS AND STREAMS. AFTER A PERIOD OF QUIET WEATHER...THUNDERSTORMS WILL BE POSSIBLE AGAIN ON SATURDAY AS A COLD FRONT APPROACHES FROM THE NORTHWEST. HEAT INDEX VALUES ARE EXPECTED TO RANGE FROM 95 TO 100 DEGREES THURSDAY...AND FROM 100 TO 105 DEGREES FRIDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND EVENING...PRIMARILY BETWEEN 2 PM AND 8 PM. ILZ066>068-071>073-221100- CLAY-CRAWFORD-EFFINGHAM-JASPER-LAWRENCE-RICHLAND- 1127 AM CDT WED JUL 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST ILLINOIS. .DAY ONE...THIS AFTERNOON AND TONIGHT SCATTERED THUNDERSTORMS WILL BE POSSIBLE THIS AFTERNOON AND EVENING...DUE TO A RESIDUAL OUTFLOW BOUNDARY ACROSS MISSOURI AND SOUTHERN ILLINOIS. THERE IS A SLIGHT RISK THAT THESE STORMS WILL BECOME SEVERE...WITH DAMAGING WINDS THE PRIMARY THREAT. A FEW OF THE STRONGER STORMS WILL ALSO BE CAPABLE OF PRODUCING AND HEAVY RAINFALL. AS A WARM FRONT APPROACHES TONIGHT...BETTER COVERAGE OF THUNDERSTORMS IS EXPECTED. THE PRIMARY THREAT TONIGHT FROM THE THUNDERSTORMS WILL BE FROM HEAVY RAINFALL AND GUSTY WINDS. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY ADDITIONAL THUNDERSTORMS WILL BE POSSIBLE THURSDAY AS THE WARM FRONT SHIFTS NORTH OF THE AREA. ANY STORMS THAT OCCUR WILL ONCE AGAIN BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL. RUN OFF FROM THIS RAINFALL WILL LEAD TO ADDITIONAL RISES ON MANY AREA CREEKS AND STREAMS. AFTER A PERIOD OF QUIET WEATHER...THUNDERSTORMS WILL BE POSSIBLE AGAIN LATER ON SATURDAY AS A COLD FRONT APPROACHES FROM THE NORTHWEST. HEAT INDEX VALUES ARE EXPECTED TO BE NEAR 100 DEGREES TODAY AND THURSDAY...AND APPROACHING 105 DEGREES ON FRIDAY. THE LITTLE WABASH RIVER WILL REMAIN ABOVE FLOOD STAGE MUCH OF THE WEEK. LOWER PORTIONS OF THE EMBARRAS RIVER MAY RISE ABOVE FLOOD STAGE BY THIS EVENING. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND EVENING...PRIMARILY BETWEEN 3 PM AND 9 PM. GEELHART
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
740 AM CDT WED JUL 21 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0530 AM HEAVY RAIN 2 E JACKSONVILLE 39.73N 90.20W
07/21/2010 M2.04 INCH MORGAN IL CO-OP OBSERVER
24 HOUR TOTAL SINCE 7 AM YESTERDAY MORNING, 7/20/2010.
0700 AM HEAVY RAIN JACKSONVILLE 39.73N 90.23W
07/21/2010 M2.24 INCH MORGAN IL CO-OP OBSERVER
24 HOUR TOTAL SINCE 7 AM YESTERDAY MORNING, 7/20/2010.
&&
BOUSLEYThe Lincoln radar (KILX), 131 km away, was scanning. The volume nearest the first event began at 18:22 UTC.
1 tornado. Local standard time, as filed.
A tornado briefly touched down in a field north of Sidell. No damage was reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2010Every state in 2010This day in weather historyThe tornado archive for Illinois, 2010Warnings in Illinois, July 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: 252558.