Strong thunderstorms moved across parts of north central and northern Illinois during the evening hours of July 29th.
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 LOT wrote it up.
Strong thunderstorms moved across parts of north central and northern Illinois during the evening hours of July 29th.
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 Chicago, IL wrote its last area forecast discussion before the first event at Jul 29, 5:35 PM CST, 1 hour 35 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 635 PM CDT TUE JUL 29 2008 .DISCUSSION... 311 PM CDT THERE IS A CHANCE OF THUNDERSTORMS TONIGHT AND WEDNESDAY. SOME OF THE THUNDERSTORMS MAY PRODUCE SMALL HAIL AND HEAVY RAINS. THE HIGH TEMPERATURES ARE FORECAST TO BE IN THE UPPER 90S SATURDAY AND SUNDAY. THERE MAY SOME DANGEROUS HEAT INDEX FOR THOSE DAYS. A SURFACE TROUGH WILL MOVE INTO ILLINOIS THIS EVENING. THIS IS A WIND SHIFT LINE THAT MAY BE A RESULT OF AGEOSTROPHIC CIRCULATION FROM THE APPROACHING 500 MB TROUGH OVER KANSAS AND OKLAHOMA. THIS TROUGH CAN BE SEEN ON THE VISIBLE SATELLITE IMAGERY AS A CIRCULATION. THE VERTICAL MOTION FROM THIS THE ADJUSTMENT CAN BE INFERRED BY THE POTENTIAL TEMPERATURE CHANGES AS THE VORTICITY MAXIMUM MOVES INTO MISSOURI AND ILLINOIS. THERE IS SOME INSTABILITY AS THE LEVEL OF FREE CONVECTION IS AROUND 6,977 FEET AS SEEN ON THE FORECAST SOUNDING AT 2 AM CDT. THE LIFTED CONDENSATION LEVEL IS FORECAST TO BE AROUND 1,858 FEET. THE INSTABILITY IS RATHER DEEP. WE WILL KEEP THE THUNDERSTORM CHANCES TONIGHT WITH THE HIGHEST PROBABILITY BEFORE AND DURING WEDNESDAY MORNING. WE EXPECT SCATTERED THUNDERSTORMS. A COLD FRONT WILL MOVE SOUTH INTO NORTHERN ILLINOIS BY LATE WEDNESDAY MORNING. WE USED THE 12 UTC RUN OF LOCAL WRF MODEL AND 12 UTC RUN OF THE NAM MODELS. FOR WEDNESDAY THIS FRONT WILL WASH OUT OVER NORTHERN ILLINOIS. THERE MAY BE ENOUGH LIFT FOR A CHANCE OF THUNDERSTORMS WEDNESDAY. THE HIGH TEMPERATES ARE EXPECTED TO CLIMB INTO THE UPPER 80S WEDNESDAY AND THURSDAY. THE WEEKEND WILL BE SIGNIFICANT WITH VERY WARM AND HUMID AIR OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA. THE GFS MODEL SHOW A LARGE 500 MB RIDGE OVER NORTHERN ILLINOIS SATURDAY. THIS LESSER DENSE AIR INDICATES VERY HIGH TEMPERATURES. WE HAVE FORECAST THE HIGH TEMPERATURES IN THE UPPER 90S FOR SATURDAY AND SUNDAY. THIS WILL GIVE HEAT INDEX AROUND 100 IN SOME LOCATIONS. WE WILL MONITOR THIS FORECAST FOR POSSIBLE HEAT ADVISORIES AND WARNINGS FOR THE WEEKEND. && .AVIATION... 635 PM CDT FOR THE 00Z TAFS...MAIN AVIATION CONCERNS WILL BE CONVECTIVE POTENTIAL THIS EVENING...AND THEN WINDS. CONVECTIVE COMPLEX WHICH DEVELOPED EARLIER THIS AFTERNOON ACROSS SOUTHERN IOWA/NORTHERN MISSOURI HAS DEVELOPED STRONG OUTFLOW ACROSS WEST CENTRAL ILLINOIS. TAMDAR DATA FROM THIS AREA INDICATING FAIRLY LARGE 850 HPA DEW PT DEPRESSIONS WHICH SHOULD ACT TO MAINTAIN OUTFLOW STRENGTH OVER THE NEXT FEW HOURS...BUT IT APPEARS AS THOUGH THE GREATER WIND THREAT SHOULD REMAIN SOUTH OF THE TERMINALS. HOWEVER...SHOULD SEE PERIOD OF SHOWERS AND THUNDERSTORMS THIS EVENING IN THE 01Z-04Z TIME PERIOD AS A SHORT WAVE TROUGH ASSOCIATED WITH REMNANTS OF DOLLY MOVES INTO NRN ILLINOIS. THIS DISTURBANCE WILL GRADUALLY WEAKEN TONIGHT AS IT LIFTS NORTHEAST AND AS DIURNAL INSTABILITY WANES EXPECTING THREAT OF PRECIP TO DIMINISH AFTER 04Z-05Z ONCE CONVECTIVE COMPLEX TO THE SOUTH EXITS THE AREA. DID MAINTAIN MENTION OF MVFR VSBYS IN LIGHT FOG/HAZE TONIGHT GIVEN WEAK WIND FIELD IN ADVANCE OF SFC FRONT THAT WILL MOVE THROUGH NRN IL TOMORROW MORNING AND ABUNDANT LOW LEVEL MOISTURE. WIND SHIFT TO THE WEST/NORTHWEST STILL LOOKS REASONABLE BY MID MORNING TOMORROW WITH WIND DIRECTIONS IN THE 270-300 DEGREE RANGE EXPECTED TOMORROW AFTERNOON AND WIND SPEEDS AROUND 10 KNOTS. HAVE KEPT TAFS DRY FOR TOMORROW WITH NEXT UPPER LEVEL SHORT WAVE OF SIGNIFICANCE NOT EXPECTED UNTIL TOMORROW EVENING. MARSILI && .MARINE... 303 PM CDT RELATIVELY DEEP LOW PRESSURE ACROSS WESTERN ONTARIO FOR LATE JULY WILL CONTINUE TO TRACK EASTWARD NORTH OF LAKE SUPERIOR TONIGHT INTO EARLY WEDNESDAY...AND INTO SOUTHERN QUEBEC WEDNESDAY NIGHT. IN THE PROCESS...A TRAILING COLD FRONT WILL MOVE SOUTHEAST ACROSS NORTHERN LAKE MICHIGAN LATE TONIGHT...AND SAG ACROSS SOUTHERN LAKE MICHIGAN WEDNESDAY. SURFACE PRESSURE FALLS ACROSS THE NORTHERN LAKES IN ADVANCE OF THIS LOW WILL TIGHTEN THE PRESSURE GRADIENT ESPECIALLY OVER NORTHERN LAKE MICHIGAN THIS EVENING...RESULTING IN STRENGTHENING SOUTHERLY WINDS OVERNIGHT. WINDS WILL THEN SHIFT TO THE WEST AND NORTHWEST WITH THE PASSAGE OF THE COLD FRONT WEDNESDAY...WITH THE GRADIENT QUICKLY DECREASING AS WEAK HIGH PRESSURE MOVES INTO THE WESTERN LAKES WEDNESDAY NIGHT AND THURSDAY. THIS HIGH WILL MOVE SOUTHEAST OF THE LAKE BY SATURDAY...WITH SOUTHERLY FLOW RETURNING AS LOW PRESSURE DEVELOPS ACROSS THE NORTHERN PLAINS. THIS LOW WILL WEAKEN BY EARLY SUNDAY AS ANOTHER LOW PUSHES ACROSS CENTRAL CANADA...AND DRAGS ANOTHER COLD FRONT SOUTHEAST ACROSS THE WESTERN LAKES. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 430 PM CDT TUE JUL 29 2008 ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019- 300930- WINNEBAGO-BOONE-MCHENRY-LAKE ILLINOIS-OGLE-LEE-DE KALB-KANE- DUPAGE-COOK-LA SALLE-KENDALL-GRUNDY-WILL-KANKAKEE-LIVINGSTON- IROQUOIS-FORD-LAKE INDIANA-PORTER-NEWTON-JASPER-BENTON- 430 PM CDT TUE JUL 29 2008/430 PM CDT TUE JUL 29 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL ILLINOIS...NORTHEAST ILLINOIS AND NORTHWEST INDIANA. .DAY ONE...TONIGHT WEATHER HAZARDS EXPECTED: A CHANCE OF THUNDERSTORMS. POSSIBLE SMALL HAIL AND STRONG GUSTS OF WIND. AREAS AFFECTED AND TIMING: THUNDERSTORMS ARE MOST LIKELY AFTER 9 PM CDT OVER NORTH CENTRAL ILLINOIS...WITH THUNDERSTORM POTENTIAL SPREADING EASTWARD TO NORTHWESTERN INDIANA AFTER MIDNIGHT. DISCUSSION: A COLD FRONT WILL MOVE ACROSS WESTERN WISCONSIN AND NORTHERN IOWA TONIGHT. AS THE FRONT APPROACHES THE MUGGY AIR MASS OVER NORTHERN ILLINOIS...THE CHANCE OF THUNDERSTORMS WILL INCREASE. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. THUNDERSTORM CHANCES WILL LINGER INTO WEDNESDAY AHEAD OF A PUSH OF HOT AIR FROM THE PLAINS STATES. HEAT WILL BE BUILDING FROM THE PLAINS STATES...INTO THE MIDWEST AS THE WEEKEND APPROACHES. TEMPERATURES MAY APPROACH 100 DEGREES BY SUNDAY...WITH THE HEAT INDEX POSSIBLY EXCEEDING 100 SATURDAY AND SUNDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED TONIGHT. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO LMZ740>745-300930- WINTHROP HARBOR TO WILMETTE HARBOR- WILMETTE HARBOR TO NORTHERLY ISLAND- NORTHERLY ISLAND TO CALUMET HARBOR-CALUMET HARBOR TO GARY- GARY TO BURNS HARBOR-BURNS HARBOR TO MICHIGAN CITY- 430 PM CDT TUE JUL 29 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF THE ILLINOIS NEARSHORE WATERS OF LAKE MICHIGAN AND THE INDIANA NEARSHORE WATERS OF LAKE MICHIGAN. .DAY ONE...TONIGHT. SCATTERED THUNDERSTORMS ARE POSSIBLE TONIGHT...ESPECIALLY AFTER MIDNIGHT. NIGHT. SOME OF THE STORMS MAY PRODUCE BRIEF GUSTY WINDS IN EXCESS OF 30 KNOTS. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. THERE WILL BE A CHANCE OF THUNDERSTORMS AGAIN ON WEDNESDAY. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868- 870-872-874-876-878-300930- LAKE MICHIGAN FROM MICHIGAN CITY IN TO ST. JOSEPH MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM SEUL CHOIX POINT TO ROCK ISLAND PASSAGE 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN SOUTH OF A LINE FROM SEUL CHOIX POINT TO THE MACKINAC BRIDGE AND NORTH OF A LINE FROM CHARLEVOIX MI TO SOUTH FOX ISLAND 5 NM OFFSHORE- LAKE MICHIGAN FROM CHARLEVOIX TO POINT BETSIE MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM POINT BETSIE TO MANISTEE MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM ROCK ISLAND PASSAGE TO STURGEON BAY WI- LAKE MICHIGAN FROM STURGEON BAY TO TWO RIVERS WI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM TOW RIVERS TO SHEBOYGAN WI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM SHEBOYGAN TO PORT WASHINGTON WI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM PORT WASHINGTON TO NORTH POINT LIGHT WI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM NORTH POINT LIGHT TO WIND POINT WI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM WIND POINT WI TO WINTHROP HARBOR IL 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM WINTHROP HARBOR TO WILMETTE HARBOR IL 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM WILMETTE HARBOR IL TO MICHIGAN CITY IN 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM PENTWATER TO MANISTEE MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM WHITEHALL TO PENTWATER MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM GRAND HAVEN TO WHITEHALL MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM HOLLAND TO GRAND HAVEN MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM SOUTH HAVEN TO HOLLAND MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM ST. JOSEPH TO SOUTH HAVEN MI 5 NM OFFSHORE TO MID LAKE- 430 PM CDT TUE JUL 29 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF THE OPEN WATERS OF LAKE MICHIGAN. .DAY ONE...TONIGHT. THUNDERSTORMS DEVELOPING ACROSS NORTHEAST WISCONSIN WILL BE MOVING OUT OVER NORTHERN LAKE MICHIGAN THIS EVENING. SOME OF THESE STORMS MAY PRODUCE WIND GUSTS IN EXCESS OF 35 KNOTS. OTHER...MORE ISOLATED THUNDERSTORMS ARE POSSIBLE OVER THE REMAINDER OF THE LAKE AFTER MIDNIGHT. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. THERE IS A CHANCE OF THUNDERSTORMS OVER THE NORTHERN PORTIONS OF LAKE MICHIGAN THROUGH SATURDAY. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO MERZLOCK
The Chicago radar (KLOT), 50 km away, was scanning. The volume nearest the first event began at 01:11 UTC.
1 thunderstorm wind. Local standard time, as filed.
Numerous tree limbs were blown down. Wind gusts were estimated between 60 and 65 mph.
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: 124162.