Powerful thunderstorms developed across eastern Iowa during the early morning hours of August 5th, then tracked eastward along an outflow boundary into the Illinois River Valley. The storms tapped into a mid-level wind max tracking through the region and were able to produce windespread wind gusts ranging from 60 to 80mph.
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.
Powerful thunderstorms developed across eastern Iowa during the early morning hours of August 5th, then tracked eastward along an outflow boundary into the Illinois River Valley. The storms tapped into a mid-level wind max tracking through the region and were able to produce windespread wind gusts ranging from 60 to 80mph. The hardest hit areas were from Peoria and Fulton counties eastward to McLean 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 5, 2:19 AM CST, 56 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 319 AM CDT TUE AUG 5 2008 .DISCUSSION... ISSUED 304 AM CDT TUE AUG 5 2008 REGION A MASS OF THUNDERSTORM CLUSTERS...FRONTS...AND OUTFLOW BOUNDARIES. ACTIVE GROUP OF THUNDERSTORMS MOVING INTO ACROSS THE MISS RIVER VALLEY THIS MORNING...SO THIS DISCUSSION WILL BE SHORTENED SOMEWHAT. APPROACHING FRONT SHOULD BE THE MAIN ISSUE FOR THE FORECAST TODAY. STORMS ALONG FRONTAL BOUNDARY AND LINGERING CLOUDS SHOULD KEEP THE NRN TIER OF COUNTIES OUT OF HEAT ADVISORY CRITERIA...THOUGH SOUTHERN AND SW COUNTIES MAY SEE HEAT INDICES IN EXCESS OF 100F. PROGRESSION OF THIS FRONT THROUGH THE FA IS REALLY THE MAIN PROBLEM FOR THE FORECAST. HAVE GONE WITH A BLEND OF THE GFS AND THE ECMWF FOR THE FORECAST AS THE NAM IS ODDLY BROADBRUSHED WITH ITS PRECIP THIS TIME AROUND. SHORT TERM...TODAY AND TOMORROW... HOT AND VERY MOIST AIR IN PLACE IN ADVANCE OF TODAYS FRONT SHOULD BRING A COUPLE ROUNDS OF TSTORMS FOR CENTRAL ILLINOIS. OUTFLOW BOUNDARY FROM LAST NIGHTS ACTIVITY ALREADY PUSHING THROUGH THE CENTRAL AND SERN PORTIONS. ANOTHER COMPLEX IS DROPPING INTO NRN CWA PRESENTLY... PROVIDING YET ANOTHER BOUNDARY. THINK AT THIS POINT THAT THE GUIDANCE MAY BE SLIGHTLY OVERDONE FOR TEMPS... BUT THE HUMIDITY MAY COMPENSATE...AS IT DID YESTERDAY...RESULTING IN HI OVER 100F. NOT MAKING ANY CHANGES TO THE ADVSY AS A RESULT. NRN TIER OF FA SHOULD END UP ON THE DRY SIDE TONIGHT AS THE FRONT MOVES THROUGH. BEST FOCUS FOR TSTORMS SHOULD BE SOUTH AND SOUTHWEST. HOWEVER... LAST COUPLE OF RUNS HAVE INDICATED A WAVE MOVING IN FROM THE WEST JUST AS THE FRONT MAY BE DRIFTING BACK NWD WITH WAA FROM THE SOUTH. HAVE GONE TO A CHANCE POP ACROSS THE FA FOR WED IN ANTICIPATION OF THIS MCS PERSISTING IN THE MODELS. LONG TERM...THURSDAY THROUGH SATURDAY... FORECAST DRIES OUT CONSIDERABLY IN THE MODELS BEYOND THURSDAY MORNING...BUT IN SKETCHY NWRLY FLOW...THAT SITUATION IS ALWAYS LIKELY TO CHANGE. BIG RIDGE BUILDING TO THE WEST...AND TS EDOUARD MOVING IN AND BEING PULLED INTO THE MIX FROM THE SW MID WEEK. TEMPERATURES IN THE LOW TO MID 80S AND NOT QUITE SO MUGGY. HJS && .AVIATION... ISSUED 1205 AM CDT TUE AUG 5 2008 TSTM COMPLEX THAT MOVED THRU NRN IL LAST EVE HAS PUSHED AN OUTFLOW BNDRY SWD THAT NOW EXTENDS BRL-BMI-DNV. ISOLD MID LVL SHOWERS FM ACCAS HAVE DVLPD SERN IA/ERN MO AND THIS ACTIVITY MAY HOLD TOGETHER AS FAR E AS PIA/SPI...BUT WILL BE DIMINISHING DUE TO SUBSIDENSE IN THE WAKE OF THE NRN IL CONVECTION. ADDITIONAL ELEVATED TSTM DVLPMT REMAINS PSBL MAINLY ALONG AND N OF OUTFLOW BNDRY...SO WILL KEEP A TEMPO FOR THUNDER IN PIA/BMI BEFORE 12Z TUE. MAIN COLD FRONT STILL BACK IN IA AND IS STILL SLATED TO REACH PIA BY 18Z AND INTO THE SPI-DEC-CMI CORRIDOR BY 21Z. WHATEVER CONVECTION DVLPS BEFORE 12Z TUE WILL HAVE A SIG IMPACT ON STORM DVLPMT/EVOLUTION THRU TUE. IN GENERAL...WILL PUT IN PROB30 FOR TSRA AFT 15Z MOST AREAS...THEN TEMPO FOR THE 4 HRS AROUND FROPA...THEN JUST A COUPLE OF HRS OF STRATOCU N OF THE FRONT. SMALL CHC FOR LINGERING CONVECTION AFTER FROPA...BUT RISK IS TOO SMALL FOR INCLUSION IN THE TAFS AT THIS TIME. 04 && .ILX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ049>052-061>063- 066>068-071>073. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LINCOLN IL 325 PM CDT MON AUG 4 2008 ILZ027>031-036>038-040>048-053>057-051100- CASS-CHAMPAIGN-COLES-DE WITT-DOUGLAS-EDGAR-FULTON-KNOX-LOGAN- MACON-MARSHALL-MASON-MCLEAN-MENARD-MOULTRIE-PEORIA-PIATT-SCHUYLER- STARK-TAZEWELL-VERMILION-WOODFORD- 325 PM CDT MON AUG 4 2008 ...HEAT ADVISORY IN EFFECT UNTIL 9 PM CDT THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL ILLINOIS AND EAST CENTRAL ILLINOIS. .DAY ONE...TONIGHT HEAT INDICES IN EXCESS OF 100 DEGREES WILL LINGER INTO THE EARLY EVENING HOURS BEFORE CONDITIONS BEGIN TO COOL DOWN AFTER SUNSET. THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS PARTS OF NEBRASKA AND IOWA THIS EVENING...THEN TRACK EASTWARD INTO NORTH CENTRAL ILLINOIS TONIGHT. CURRENT INDICATIONS SUGGEST THUNDERSTORMS WITH DAMAGING WINDS MAY IMPACT PARTS OF THE AREA...PRIMARILY ALONG AND NORTH OF A PEORIA TO BLOOMINGTON LINE. IF THE STORMS MATERIALIZE AS EXPECTED...THE MAIN TIME FRAME FOR POTENTIAL SEVERE WEATHER ACROSS CENTRAL ILLINOIS WOULD BE FROM 9 PM TO 3 AM. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THUNDERSTORMS WILL CONTINUE TO MOVE THROUGH THE REGION ON TUESDAY AS A COLD FRONT MOVES INTO ILLINOIS. THERE IS A SLIGHT RISK SOME OF THESE STORMS COULD BECOME SEVERE WITH LARGE HAIL AND DAMAGING WIND GUSTS POSSIBLE. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED LATER TONIGHT...PRIMARILY BETWEEN 9 PM AND 3 AM. ILZ049>052-061>063-066>068-071>073-051100- CHRISTIAN-CLARK-CLAY-CRAWFORD-CUMBERLAND-EFFINGHAM-JASPER- LAWRENCE-MORGAN-RICHLAND-SANGAMON-SCOTT-SHELBY- 325 PM CDT MON AUG 4 2008 ...HEAT ADVISORY IN EFFECT UNTIL 7 PM CDT TUESDAY... THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL ILLINOIS...EAST CENTRAL ILLINOIS AND SOUTHEAST ILLINOIS. .DAY ONE...TONIGHT HEAT INDICES IN EXCESS OF 100 DEGREES WILL LINGER INTO THE EARLY EVENING HOURS BEFORE CONDITIONS BEGIN TO COOL DOWN AFTER SUNSET. THUNDERSTORMS ARE EXPECTED TO TRACK ACROSS NORTH CENTRAL ILLINOIS LATER THIS EVENING INTO THE OVERNIGHT HOURS. SOME OF THESE STORMS MAY REACH AS FAR SOUTH AS THE I-72 CORRIDOR AFTER MIDNIGHT...HOWEVER THE PRIMARY SEVERE WEATHER THREAT WILL REMAIN FURTHER NORTH. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THUNDERSTORMS WILL MOVE THROUGH THE REGION TUESDAY AND TUESDAY NIGHT AS A COLD FRONT DROPS INTO ILLINOIS. THERE IS A SLIGHT RISK SOME OF THESE STORMS COULD BECOME SEVERE WITH LARGE HAIL AND DAMAGING WIND GUSTS POSSIBLE TUESDAY AND TUESDAY NIGHT. HEAT AND HUMIDITY WILL CONTINUE INTO TUESDAY WITH APPARENT TEMPERATURES AROUND 100 DEGREES BY THE AFTERNOON. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED THROUGH TONIGHT. BARNES
The Quad Cities radar (KDVN), 92 km away, was scanning. The volume nearest the first event began at 09:15 UTC.
15 thunderstorm wind. Local standard time, as filed.
Trees were blown down onto powerlines.
Several large trees were blown down.
Two and a half to three-foot diameter tree branches were blown down.
Two outbuildings were destroyed. A garage was damaged, with debris from the structure blocking a road. One horse was injured.
Numerous trees were blown down around the city of Peoria.
A thirty six-inch diameter tree was split by strong winds.
An aluminum flag pole was snapped by strong winds.
A three-foot diamter tree was blown down onto a house.
Three six to eight-inch diameter trees were snapped by strong winds.
Around a dozen oak trees were sheared off by high winds at Lake Eureka.
Several trees were blown down onto powerlines.
Trees were blown down onto powerlines on the north side of Normal.
Powerlines were blown down around Colfax, resulting in approximately 600 people losing power.
Twenty five to thirty large trees were blown down in Hoopeston. One tree destroyed a car.
Numerous trees were blown down in Danville.
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, August 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: 132186, 132187, 132201, 132188, 132189, 132204, 132190, 132191, 132202, 132521, 132193, 132195, 132196, 132197, 132198.