Thunderstorms developed along an approaching cold front during the afternoon of 7/20/08. A few of the storms across east-central Illinois produced hail and damaging wind gusts, particularly across Vermilion County.
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.
Thunderstorms developed along an approaching cold front during the afternoon of 7/20/08. A few of the storms across east-central Illinois produced hail and damaging wind gusts, particularly across 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 20, 2:00 PM CST, 0 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 300 PM CDT SUN JUL 20 2008 .DISCUSSION... ISSUED 300 PM CDT SUN JUL 20 2008 A COMPLEX...THOUGH RELATIVELY TYPICAL...SUMMER WEATHER PATTERN PERSIST ACROSS THE FORECAST AREA THIS AFTERNOON. THE ATMOSPHERE OVER MUCH OF THE FORECAST AREA HAS BECOME UNCAPPED AND HAS CAPE VALUES TO 3500 J/KG AND LI VALUES TO -6C. A WEAK SURFACE BASED CONVERGENT/CONFLUENT ZONE IS NOTED IN THE OBSERVED WIND FIELD... ROUGHLY ALONG THE I-74 CORRIDOR. AN ENHANCED CU FIELD IS ALSO EVIDENT IN THIS AREA. MAIN FORECAST CONCERN OVER THE NEXT FEW DAYS REVOLVES AROUND PRECIPITATION CHANCES INTO TUESDAY. THESE CHANCES WILL INITIALLY BE AROUND THE CONVERGENCE ZONE THIS EVENING...WITH AN MCS TONIGHT...AND ALONG/AHEAD OF A COLD FRONT THAT IS EXPECTED TO PASS THROUGH THE REGION MONDAY INTO EARLY TUESDAY. 12Z MODELS IN REASONABLE AGREEMENT WITH MAIN FEATURES EXPECTED TO IMPACT FORECAST AREA. DO NOT EXPECT STRONG MODEL AGREEMENT OR TRUST THE DETAILS OF ANY ONE MODEL IN THIS CONVECTIVELY INFLUENCED ENVIRONMENT. SHORT TERM...TONIGHT THROUGH WEDNESDAY... TONIGHT THROUGH TUESDAY...SCATTERED THUNDERSTORMS ARE POSSIBLE THIS EVENING ALONG THE ABOVE MENTIONED LOW LEVEL BOUNDARY...AT LEAST UNTIL DIURNAL INSTABILITY DIMINISHES. THEN...ATTENTION TURNS TOWARD NOCTURNAL MCS DEVELOPMENT UPSTREAM. OUR LOW LEVEL BOUNDARY EXTENDS WEST NORTHWEST TOWARD THE NEBRASKA/IOWA BORDER. MODEL PROGS GENERALLY AGREE THAT THIS IS WHERE THE LOW LEVEL JET WILL INITIALLY BE MAXIMIZED TONIGHT. EXPECT MCS TO INITIATE IN THIS AREA...AHEAD OF A DIGGING UPPER WAVE/WIND SPEED MAX IN THE UPPER MIDWEST...AND TRACK ALONG THE LOW LEVEL THETA-E RIDGE AXIS. THIS RIDGE AXIS HAPPENS TO COINCIDE WITH THE CURRENT SURFACE BOUNDARY ALONG I-74. ONCE THE MCS DEPARTS MONDAY MORNING...ADDITIONAL SHOWER/STORM CHANCES ARE EXPECTED MONDAY INTO MONDAY NIGHT AS UPPER MIDWEST WAVE PUSHES THE ACTUAL SURFACE COLD FRONT THROUGH THE REGION. DEPENDING ON THE SPEED OF THE UPPER WAVE/SURFACE FRONT...PRECIPITATION CHANCES MAY LINGER INTO EARLY TUESDAY. SEVERE WEATHER THREAT...PRECIPITABLE WATER VALUES ARE EXPECTED TO BE AROUND 2 INCHES THROUGH FRONTAL PASSAGE. ALSO...AT LEAST INITIALLY...THE WIND FIELDS ARE QUITE WEAK AND SUPPORT SLOW STORM MOVEMENT. THIS WOULD SUPPORT FLOODING AS A POTENTIAL THREAT. THE WIND FIELDS PICK UP LATER TONIGHT INTO MONDAY AS THE MAIN UPPER WAVE AND FRONT PUSH IN. THESE STRONGER WIND FIELDS MAY SUPPORT DAMAGING WIND GUSTS. TUESDAY NIGHT AND WEDNESDAY...NORTHWEST FLOW BECOMES ESTABLISHED ALOFT AS THE SURFACE FRONT SETTLES INTO THE OHIO VALLEY. THIS SIGNALS THE RETURN OF QUIETER WEATHER...AS WELL AS SOMEWHAT COOLER AND LESS HUMID CONDITIONS. LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...MODELS/ENSEMBLES CONTINUE TO SHOW GENERAL AGREEMENT ON THE LARGER SCALE FLOW... BUT DIFFER CONSIDERABLY ON THE SMALL SCALE DETAILS. MAIN SURFACE FRONT/LOW LEVEL BAROCLINIC ZONE EXPECTED TO BE DRAPED ACROSS THE OHIO VALLEY...NOT TOO FAR SOUTH OF THE FORECAST AREA...WITH PREDOMINANTLY NORTHWEST FLOW ALOFT. TWO SCENARIOS WOULD BRING ENHANCED CHANCES OF PRECIPITATION TO THE REGION WITH THIS GENERAL SETUP. THE FIRST IS AN IMPULSE DROPPING ACROSS THE REGION IN THE NORTHWEST FLOW. THE SECOND IS UPPER RIDGING OVER WESTERN NORTH AMERICA BUILDING TO THE EAST AND LIFTING THE LOW LEVEL FRONT/BAROCLINIC ZONE BACK INTO THE FORECAST AREA. NEITHER OF THESE SCENARIOS IS AGREED UPON BY THE MODELS...SO WILL NOT CARRY ABOVE A SLIGHT CHANCE OF SHOWERS/STORMS AT THIS TIME. ASSUMING THE FRONT STAYS TO OUR SOUTH AND THE UPPER RIDGE TO OUR WEST... TEMPERATURES/HUMIDITIES WILL BE AT LEAST SLIGHTLY BELOW THOSE AT THE START OF THE WEEK. BAK && .AVIATION... ISSUED 1232 PM CDT SUN JUL 20 2008 MULTIPLE OUTFLOW BOUNDARIES FROM OLD CONVECTION CREATING A BIT OF A FORECAST PROBLEM WITH THE MODEL PERFORMANCE. VERY ISOLATED AND SCATTERED THUNDERSTORMS ACROSS MUCH OF THE MIDWEST. AS A RESULT...HAVE KEPT VCTS IN TAFS FOR MUCH OF THE FIRST PERIOD. COVERAGE IS THIN ENOUGH TO KEEP FROM BEING THE PREDOMINANT WEATHER... AT LEAST UNTIL CLOSER TO MIDNIGHT AS THE WAVE PUSHING THROUGH THE UPPER MIDWEST ACTUALLY GETS HERE...KEEPING THE MAJORITY OF THE PRECIP IN THE NRN TERMINAL SITES. HJS && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LINCOLN IL 1104 AM CDT SUN JUL 20 2008 ILZ027>031-036>038-040>057-061-211100- CASS-CHAMPAIGN-CHRISTIAN-COLES-DE WITT-DOUGLAS-EDGAR-FULTON-KNOX- LOGAN-MACON-MARSHALL-MASON-MCLEAN-MENARD-MORGAN-MOULTRIE-PEORIA- PIATT-SANGAMON-SCHUYLER-SCOTT-SHELBY-STARK-TAZEWELL-VERMILION- WOODFORD- 1104 AM CDT SUN JUL 20 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL ILLINOIS AND EAST CENTRAL ILLINOIS. .DAY ONE...THIS AFTERNOON AND TONIGHT THE COMBINATION OF AIR TEMPERATURES IN THE LOWER TO MIDDLE 90S THIS AFTERNOON ALONG WITH HIGH HUMIDITY LEVELS WILL PRODUCE HEAT INDEX VALUES IN THE UPPER 90S. DRESS PROPERLY FOR THE HEAT TODAY AND DRINK PLENTY OF FLUIDS. THERE WILL BE A SLIGHT CHANCE FOR THUNDERSTORMS THIS AFTERNOON AND EARLY THIS EVENING. HOWEVER...THE BETTER CHANCES FOR MORE ORGANIZED AND POSSIBLY SEVERE THUNDERSTORMS WILL BE LATER TONIGHT INTO EARLY MONDAY MORNING AS A COLD FRONT SLIPS SOUTH INTO CENTRAL ILLINOIS. THE PRIMARY THREAT OVERNIGHT WILL BE FROM DAMAGING WINDS...LARGE HAIL AND TORRENTIAL RAINFALL WHICH MAY LEAD TO FLASH FLOODING. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY THERE WILL BE A CHANCE FOR THUNDERSTORMS INTO AT LEAST TUESDAY AS THE COLD FRONT MAKES SLOW PROGRESS SOUTHWARD ACROSS THE STATE. ONCE AGAIN...THE THREAT FOR SEVERE THUNDERSTORMS WILL PREVAIL ACROSS THE AREA ON MONDAY WITH THE PRIMARY THREAT BEING FROM STRAIGHT LINE WIND DAMAGE AND LARGE HAIL. THE STORM THREAT WILL SHIFT SOUTH OF THE AREA TUESDAY NIGHT THROUGH WEDNESDAY AS WEAK HIGH PRESSURE BUILDS IN FROM THE NORTH. HOWEVER...AS THE BOUNDARY STARTS TO RETURN NORTH AS A WARM FRONT LATE WEDNESDAY NIGHT INTO THURSDAY...THUNDERSTORM CHANCES WILL BEGIN TO INCREASE AGAIN ACROSS THE AREA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY...HOWEVER ACTIVATION MAY BE REQUIRED LATER THIS EVENING INTO EARLY MONDAY MORNING. ILZ062-063-066>068-071>073-211100- CLARK-CLAY-CRAWFORD-CUMBERLAND-EFFINGHAM-JASPER-LAWRENCE-RICHLAND- 1104 AM CDT SUN JUL 20 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL ILLINOIS AND SOUTHEAST ILLINOIS. .DAY ONE...THIS AFTERNOON AND TONIGHT THE COMBINATION OF AIR TEMPERATURES IN THE MIDDLE 90S THIS AFTERNOON ALONG WITH HIGH HUMIDITY LEVELS WILL PRODUCE HEAT INDEX VALUES APPROACHING 100 DEGREES. DRESS PROPERLY FOR THE HEAT TODAY AND DRINK PLENTY OF FLUIDS. THERE WILL BE A SLIGHT CHANCE FOR THUNDERSTORMS THIS AFTERNOON AND EARLY THIS EVENING. HOWEVER...THE BETTER CHANCES FOR MORE ORGANIZED AND POSSIBLY SEVERE THUNDERSTORMS WILL BE LATER TONIGHT INTO EARLY MONDAY MORNING AS A COLD FRONT SLIPS SOUTH INTO CENTRAL ILLINOIS. THE PRIMARY THREAT OVERNIGHT WILL BE FROM DAMAGING WINDS AND TORRENTIAL RAINFALL. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY THERE WILL BE A CHANCE FOR THUNDERSTORMS INTO AT LEAST TUESDAY AS THE COLD FRONT MAKES SLOW PROGRESS SOUTHWARD ACROSS THE STATE. ONCE AGAIN...THE THREAT FOR SEVERE THUNDERSTORMS WILL PREVAIL ACROSS THE AREA ON MONDAY WITH THE PRIMARY THREAT BEING FROM STRAIGHT LINE WIND DAMAGE AND LARGE HAIL. THE STORM THREAT WILL SHIFT SOUTH OF THE AREA TUESDAY NIGHT THROUGH WEDNESDAY AS WEAK HIGH PRESSURE BUILDS IN FROM THE NORTH. HOWEVER...AS THE BOUNDARY STARTS TO RETURN NORTH AS A WARM FRONT LATE WEDNESDAY NIGHT INTO THURSDAY...THUNDERSTORM CHANCES WILL BEGIN TO INCREASE AGAIN ACROSS THE AREA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY...HOWEVER ACTIVATION MAY BE REQUIRED LATER THIS EVENING AND INTO EARLY MONDAY MORNING. HJS
The Indianapolis radar (KIND), 128 km away, was scanning. The volume nearest the first event began at 20:01 UTC.
4 thunderstorm wind, 1 hail. Local standard time, as filed.
Numerous 2 to 3 foot diameter trees were blown down in Catlin.
Power lines were blown down on the southeast side of Danville.
Numerous power lines were blown down in Georgetown.
Three quarter inch hail fell 3 miles south of Georgetown.
Three foot diameter tree was blown over onto an unoccupied truck.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2008Every state in 2008This day in weather historyWarnings in Illinois, July 2008
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: 123788, 123790, 123792, 123787, 123794.