Severe storms moved across northwest Illinois during the early morning hours of August 14th.
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.
Severe storms moved across northwest Illinois during the early morning hours of August 14th.
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 Aug 14, 2:30 AM CST, 48 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 330 AM CDT TUE AUG 14 2007 .DISCUSSION... 315 AM CDT GEARING UP FOR SEVERE WEATHER DURING THE EARLY MORNING HOURS FOR WESTERN PORTIONS OF THE CWA. HAVE BEEN MONITORING MCS MOVING SWD THROUGH WISCONSIN OVERNIGHT. EXPECTING THE MAIN CONVECTIVE LINE TO MOVE INTO NORTH CENTRAL AND NWRN ILLINOIS BY ZONE ISSUANCE TIME. THE AXIS OF STRONGEST INSTABILITY IS ALONG THE MISSISSIPPI RIVER AND A STRONG DEW POINT GRADIENT IS IN PLACE ALONG THE INTERSTATE 39 CORRIDOR. EXPECT THE CONVECTIVE LINE ASSD WITH THE MCS TO TRACK SWD ALG THE DEWPOINT GRADIENT. FOR THE REMAINDER OF THE SHORT TERM...HAVE GENERALLY GONE ALONG WITH THE NAM12 GUIDANCE AS FAR AS THE TIMING OF THE LARGE SCALE FEATURES...THOUGH DO NOT SEE A WHOLE LOT OF DIFFERENCE BETWEEN THE NAM AND GFS AS FAR AS THE SYNOPTIC SCALE IS CONCERNED. THE GENERAL PATTERN OF FRONTAL PASSAGES FOLLOWED BY BUILDING HIGH PRESSURE WILL CONTINUE FOR THE NEXT FEW DAYS. HAVE TIMED THE NEXT FRONTAL PASSAGE TO OCCUR BY LATE THIS AFTERNOON. WHILE THE AIRMASS ACROSS MUCH OF THE CWA...PARTICULARLY THE WRN PORTIONS...WILL BE WORKED OVER BY EARLY MORNING CONVECTION...THERE WILL STILL BE A CHANCE OF ADDITIONAL TSRA OVER ERN PORTIONS OF THE CWA WITH THE FROPA. SFC DEWPOINTS WILL GRADUALLY INCREASE THROUGH THE DAY TODAY AS SFC HIGH PRESSURE OVER THE OHIO VALLEY SHIFTS EWD AND INCRG SSWLY FLOW ENHANCES MOISTURE TRANSPORT. WEDNESDAY IS LOOKING TO BE QUITE ACTIVE AS WELL WITH A SFC LOW DEVELOPING OVER THE CNTRL PLAINS AND A WARM FRONT SETS UP OVER CNTRL IL WEDNESDAY MORNING. STRONG ISENTROPIC LIFT ASSD WITH THE WARM FRONT WILL ENHANCE TSTM DEVELOPMENT WEDNESDAY AFTERNOON...AND ANOTHER ROUND OF SEVERE WX IS LIKELY. THE UNUSUALLY ACTIVE PATTERN WILL CONTINUE INTO THURSDAY WITH YET ANOTHER FRONTAL PASSAGE EXPECTED. HAVE ONLY MADE MINOR ADJUSTMENT TO THE GOING FORECAST FOR THE LATTER PORTIONS OF THE SHORT TERM AND INTO THE LONGER TERM THE BETTER DEFINE THE FROPA ON THURSDAY. OTHERWISE...HAVE NOT MADE MUCH ADJUSTMENT TO THE LONGER TERM FORECAST PERIODS. KREIN && .AVIATION DISCUSSION REGARDING 06Z TAFS... 1230 AM CDT CONCERN OVERNIGHT WILL CONTINUE TO FOCUS ON TSTM CLUSTERS MOVG SEWD FROM SERN MN/W CNTRL WI. CURRENT SATLT RADAR TRENDS SHOW THESE STORMS MAINTAINING INTENSITY AS THEY HEAD FROM 320 DEG AT ABOUT 35 KTS. THIS WOULD PUT LEADING EDGE OF STGR STORMS...NOW ABOUT 20 W VOK...INTO RFD AREA ABOUT 08Z OR SHORTLY THEREAFTER. SECOND CLUSTER JUST N OF RST DISPLAYS SIMILAR MOVMT. CURRENT ANALYSES SHOW MOST PROLIFIC INFLOW OF WARM MOIST AIR INTO THESE STORMS COMING IN FROM W ACROSS IA/SRN MN. THEREFORE...EXPECT STGST STORMS TO AFFECT WRN PORTIONS OF TERMINAL AREA...ESP FROM RFD SSEWD THRU VYS/DKB AREAS...IN CLOSER PROXIMITY TO LLVL MOISTURE SUPPLY WHERE UPDRAFTS WILL LIKELY BE STGR AND MORE ACTIVE. BASED ON THIS...AND TYPICAL EVOLUTION OF THESE NOCTURNAL CLUSTERS...EXPECT TSTM OUTFLOW TO BCM MORE ORGANIZED WITH TIME DURG PRE DAWN HRS SO HAVE INCLUDED TEMPO NWLY WIND GUSTS IN RFD/DPA TAFS AS THESE STMS MOVE THRU. CHCS FOR STGR OUTFLOW WINDS APPEAR TO DMNSH FURTHER E WHERE AMS RMNS DRIER AND FURTHER REMOVED FROM STGR LLVL FORCING. WILL KEEP SOME RESIDUAL SHWRS IN FCST THRU MID MRNG AS CONVECTION SLIDES OFF TO SE AND BEGINS TO ENTER DIURNAL WEAKENING PERIOD. CONDS TO BCM GENLY VFR AFTR STORMS MOVE THRU...WITH CHCS FOR NEW TSTM DVLPMT S OF TERMINALS AS COLD FRONT PASSES THROUGH AREA MID-LATE AFTN AND INSTABILITY IS ALLOWED TO RECOVER ACROSS AREAS S OF I-80.../PNT-IKK-VPZ AREAS/. WINDS BHD FRONT TO TURN NNWLY...THEN NNELY DURG EVENING HRS. GUIDANCE FCSTS OF LLVL RH FIELDS SUGGEST LOW CLOUD LYR DVLPG IN FLOW OFF LK MI...OVR NERN IL/NWRN IND DURG EVENING HRS. FOR NOW WILL ONLY LWR CIGS IN CHI AREA TO MVFR RANGE AFT 03Z. MERZLOCK && .MARINE DISCUSSION... 330 AM CDT A LOW PRESSURE CENTER OVER CENTRAL ONTARIO HAS A COLD FRONT TRAILING SOUTHWEST ACROSS WESTERN LAKE SUPERIOR...AND ON TO THE CENTRAL PLAINS STATES. THIS FRONT WILL MOVE SOUTHEASTWARD ACROSS THE WESTERN GREAT LAKES TODAY...CROSSING LAKE MICHIGAN THIS AFTERNOON. STRONG THUNDERSTORMS ARE EXPECTED TO STAY WEST OF LAKE MICHIGAN TODAY...BUT MORE STORMS ARE POSSIBLE AGAIN ON WEDNESDAY. HIGH PRESSURE WILL THEN BUILD ACROSS THE UPPER LAKES TONIGHT AND EARLY WEDNESDAY...BEFORE SETTLING OVER THE UPPER OHIO VALLEY AND GIVING WAY TO YET ANOTHER DEVELOPING LOW OVER NORTHWEST ONTARIO. THIS LOW IS FORECAST TO DEEPEN CONSIDERABLY BY THE TIME IT REACHES JAMES BAY THURSDAY MORNING. A STRONG COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL SWEEP ACROSS LAKE MICHIGAN LATE WEDNESDAY NIGHT AND THURSDAY. MERZLOCK && .LOT WATCHES/WARNINGS/ADVISORIES... IL...SEVERE THUNDERSTORM WATCH 596 UNTIL 7AM CDT FOR NWRN AND NCNTRL IL. IN...NONE. LM...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 420 PM CDT MON AUG 13 2007 ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019- 142130- 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- 420 PM CDT MON AUG 13 2007 /520 PM EDT MON AUG 13 2007/ THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND NORTHEAST ILLINOIS...AND NORTHWEST INDIANA. .DAY ONE...TONIGHT. THERE IS A CHANCE OF THUNDERSTORMS MOVING INTO NORTH CENTRAL AND NORTHEAST ILLINOIS AFTER MIDNIGHT. SOME OF THESE THUNDERSTORMS MAY PRODUCE SEVERE WEATHER. THE PRIMARY THREAT WOULD BE DAMAGING WIND AND HEAVY RAIN. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. THERE WILL BE A CHANCE OF THUNDERSTORMS TUESDAY THROUGH THURSDAY. THERE IS A SLIGHT RISK THAT THE THUNDERSTORMS DURING TUESDAY MAY BE SEVERE. THE MAIN THREAT WOULD BE DAMAGING WIND AND HEAVY RAIN. THERE WILL BE ANOTHER CHANCE OF THUNDERSTORMS SATURDAY THROUGH MONDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED LATE TONIGHT AND EARLY TUESDAY MORNING. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO LMZ740>745-766-142130- WINTHROP HARBOR TO WILMETTE HARBOR IL- WILMETTE HARBOR TO NORTHERLY ISLAND IL- NORTHERLY ISLAND TO CALUMET HARBOR IL- CALUMET HARBOR IL TO GARY IN-GARY INDIANA TO BURNS HARBOR- BURNS HARBOR TO MICHIGAN CITY- LAKE MICHIGAN, WINTHROP HARBOR IL EASTWARD TO THE MID- POINT OF THE LAKE AND SOUTHWARD TO MICHIGAN CITY MI BEYOND 5 NM OFFSHORE- 420 PM CDT MON AUG 13 2007 THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS AND INDIANA WATERS OF LAKE MICHIGAN. .DAY ONE...TONIGHT. THERE WILL BE A CHANCE OF THUNDERSTORMS TONIGHT. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. THERE WILL BE A CHANCE OF THUNDERSTORMS TUESDAY THROUGH THURSDAY. THERE WILL BE ANOTHER CHANCE OF THUNDERSTORMS SATURDAY THROUGH MONDAY. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
332 AM CDT TUE AUG 14 2007
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0332 AM TSTM WND GST ROCKTON 42.45N 89.07W
08/14/2007 M52 MPH WINNEBAGO IL TRAINED SPOTTER
&&
ALLSOPPThe Milwaukee radar (KMKX), 99 km away, was scanning. The volume nearest the first event began at 09:16 UTC.
11 thunderstorm wind. Local standard time, as filed.
A large tree was blown down at the intersection of Best and Norris Roads.
A tree was blown down.
A tree was blown down at Pine and West Lane, blocking traffic.
Tree down at State and Alpine Roads.
Large parts of two trees were blown down, both onto power lines.
A tree and limbs were blown down near Lake Summerset and the Winnebago Stephenson County line.
Tree limbs were blown down.
Tree limbs and power lines were blown down on Hillside Avenue in northern Ottawa.
A grain silo was blown over near 2276th Road.
A tree was blown down blocking one lane of traffic.
A tree limb was blown down onto power lines causing a fire.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2007Every state in 2007This day in weather historyWarnings in Illinois, August 2007
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: 54795, 54796, 54797, 54798, 54799, 54800, 54801, 56731, 56725, 54802, 54803.