Flash Flooding and Flooding in Illinois, July 18 to 19, 2007

Name: Flash Flooding and Flooding in Illinois, July 18 to 19, 2007
Start: 2007-07-18T18:22
End: 2007-07-19T00:00
Location: Illinois

July 18 to 19, 2007 · NWS LOT · 38 events in 10 counties and zones

Severe thunderstorms developed during the early evening hours of July 18th and moved across northern Illinois.

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 38

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.

What happened

The episode as NWS LOT wrote it up.

Severe thunderstorms developed during the early evening hours of July 18th and moved across northern Illinois.

What forecasters said that day

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 18, 6:00 PM CST, 22 minutes earlier.

Area forecast discussion, Jul 18, 6:00 PM CST, 22 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
700 PM CDT WED JUL 18 2007

.DISCUSSION...220PM
COMPLEX AND POTENTIALLY POTENT SITN CONTINUING WITH ASSORTED THREATS
DURING THE NOCTURAL HRS. LAST NIGHTS RAIN FROM OGLE AND LEE COUNTIES
SEWD INTO LASALLE AND LIVINGSTON COUNTIES MAKE THESE AREAS VERY
VULNERABLE TO ADDITIONAL RAIN AND SUBSEQUENT FLOODING TNGT AND
THURSDAY.

UPPER TROUGH WHICH HAS SUPPORTED SEWD MOVING MCS SYSTEMS PAST 2 DAYS
WILL BE BUCKLING LATER TONIGHT AND THURSDAY WITH SHORT WAVE PIVOTING
SWD FROM MANITOBA THROUGH THE MIDWEST DRAGGING COOLER AIR INTO
REGION LATER THURSDAY.  SECOND IMPULSE IS MOVING OUT OF THE WESTERN
DAKS THIS AFTN AND WILL SLIDE ESE AHEAD OF HIGHER AMPLITUDE DEVELMT.
THIS LATTER SYSTEM IS NOW BEGINNING TO INTERACT WITH BAROCLINIC ZONE
STRETCHING FROM SE SDAK ACROSS NRN IOWA INTO SRN WISC.  VERY MOSIT
AIR SOUTH OF THIS BOUNDARY WILL BE THE FUEL FOR TSTMS/MCS EXPECTED
TO FORM OVER WRN IOWA OR SW MINN DURING THE LATE AFTN.  WHOLE FLOW
PATTERN IS NOW MORE E-W SO EXPECT ANY ORGANIZED CONVECTION TO MOVE
TWD NRN ILL DURING THE NIGHT.  AVAILABLE ACARS SOUNDINGS AND MODEL
SOUNDINGS FROM ORD WESTWARD ACROSS IOWA SHOW A CONTINUED VERY DEEP
NEARLY ADIABATIC LAPSE RATE IN AN ELEVATED ZONE ABOVE 850MB.
POCKETS OF DRY AIR ALSO SEEN IN THESE WHICH SUGGESTS BOTH STRONG
BUOYANCY AS WELL AS WIND POTENTIAL.

AT THIS POINT EXPECT CONVECTION SHOULD ORGANIZE ALONG THE IOWA/MINN
BORDER MORE OR LESS..AND TRACK EAST OR ESE INTO NRN ILLINOIS DURING
THE LATE EVENING OR AFTER MIDNIGHT. CANNOT IGNORE SLOW APPROACH OF
MAIN CANADIAN FRONT INTO NRN WISC WHICH MAY INITIATE ITS OWN ZONE OF
CONVECTION BUT AT THIS POINT THE SHORT WAVE ENHANCED CONVECTION FROM
THE WEST IS OF MORE CONCERN.

FLOODING...SOUTH AND WESTERN PORTIONS OF CWA SATURATED. DIFFERENCE
IN TONIGHTS SITUATION IS A BETTER INFLOW EXPECTED ACROSS IOWA AND
NRN MISSOURI. 925MB AND 850MB MODEL WINDS ARE WELL ORGANIZED DURING
THE NIGHT WITH UP TO 35KTS SEEN ON THE NAM80. THUS LOW LEVEL FORCING
OF MOIST AIR INTO CONVECTIVE CLUSTERS MAY IMPROVE RAIN PRODUCTION.
WILL LEAVE FFA AS IS FOR NOW IT BOTH TIME...12Z THUR...AND AREA.
PRECIP WILL FADE OFF TO THE SE THUSDAY AFTERNOON.

FROM FRIDAY ONWARD ALL GUIDANCE SUGGESTS A LARGE SLOW MOVING
ANTICYCLONE WILL PARK OVER THE MIDWEST WITH SLOW MODIFICATION OF
TEMPS AFTER SUNDAY. NO READON TO ARGUE AS UPPER AIR PATTERN FEATURES
A HIGH AMPLITUDE RIDGE FROM THE PLAINS INTO THE MIDWEST.  KML

&&

.AVIATION...

00Z TAFS...AREA OF THUNDERSTORMS DEVELOPING ACROSS FAR NORTHERN IL
ACROSS THE PAST HR AND CONINTUING TO EXPAND TO THE SE. HAVE CARRIED
TEMPO TS FOR THE FIRST FEW HRS WITH THE EXPECTATION THAT THIS
ACTIVITY WOULD BE PUSHING EAST OF THE TERMINALS. BUT DEVELOPMENT
CONTINUES ACROSS NW IL/SW WI SO THIS WILL LIKELY NEED TO BE ADJUSTED
AS THE EVENING GOES ON. SECOND TEMPO TS WAS FOR THE MAIN LINE OF TS
ACROSS IA WHICH...NOW APPEARS LIKE IT WILL PUSH SOUTHEAST...MAINLY
SOUTH OF THE TAFS DURING THE LATE EVENING AND EARLY MORNING HRS BUT
RAIN WITH EMBEDDED TS STILL LOOKS REASONABLE. PRECIP CHANCES AROUND
SUNRISE QUESTIONABLE AND WILL NEED TO BE LOOKED AT WITH NEXT SET OF
TAFS. FRONT MOVES THRU THE AREA LATE THURSDAY MORNING SHIFTING WINDS
NORTH...THEN SPEEDS INCREASE IN THE AFTERNOON WITH GUSTS 20-25KTS.
CMS

&&

.MARINE DISCUSSION...

245 PM CDT

A WEAK AND DIFFUSE FRONTAL TROUGH FROM SOUTHERN
MINNESOTA...SOUTHEASTWARD ACROSS SOUTHERN LAKE
MICHIGAN WILL REMAIN STATIONARY THROUGH THIS EVENING. MEANWHILE...A
LOW PRESSURE CENTER OVER NEBRASKA WILL MOVE EASTWARD ACROSS THE
UPPER MIDWEST TONIGHT...TO A POSITION NEAR DETROIT BY THURSDAY
MORNING.  AS THIS LOW MOVES EAST OF THE LAKE TONIGHT...A
TRAILING COLD FRONT WILL SURGE SOUTHWARD ACROSS LAKE
MICHIGAN...CLEARING THE SOUTH END OF THE LAKE EARLY THURSDAY
MORNING. IN THE WAKE OF THIS FRONT...A HIGH PRESSURE CENTER WILL
BUILD ACROSS MINNESOTA AND INTO THE WESTERN GREAT LAKES THURSDAY AND
FRIDAY. THIS WILL CREATE HAZARDOUS CONDITIONS FOR SMALL CRAFT ACROSS
SOUTHERN LAKE MICHIGAN FROM THURSDAY AFTERNOON THROUGH FRIDAY DUE TO
NORTH WINDS IN EXCESS OF 20 KNOTS AND WAVES IN EXCESS OF 5 FEET
THROUGH THE PERIOD.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLOOD WATCH UNTIL 12Z THURSDAY FOR OGLE...LEE...LA SALLE...
GRUNDY...LIVINGSTON...IROQUOIS AND FORD.
IN...FLOOD WATCH UNTIL 12Z THURSDAY FOR BENTON.
LM...SMALL CRAFT ADVISORY 15Z THURSDAY THROUGH 03Z SATURDAY.

&&

Hazardous weather outlook, Jul 18, 3:00 PM CST, 3 hours 22 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
400 PM CDT WED JUL 18 2007

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
190930-
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-
400 PM CDT WED JUL 18 2007

THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR NORTH
CENTRAL AND NORTHEAST ILLINOIS...AND NORTHWEST INDIANA.

.DAY ONE...TONIGHT.

THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS MOST
OF NORTHERN ILLINOIS AND A SMALL PORTION OF NORTHWEST INDIANA.
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ELSEWHERE.

THE MODERATE RISK AREA IS ALONG AND SOUTH OF A LINE FROM
ROCKFORD...TO DOWNTOWN CHICAGO...TO PORTAGE INDIANA.

ISOLATED THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING
WILL GIVE WAY TO MORE ORGANIZED STORMS MOVING IN FROM THE WEST
TOWARD AND AFTER MIDNIGHT.

THESE STORMS MAY EVOLVE INTO A LINEAR CLUSTER CAPABLE OF PRODUCING
DAMAGING WINDS AS IT MOVES EAST SOUTHEASTWARD INTO NORTHERN ILLINOIS
LATER THIS EVENING.

FLOODING...
HEAVY RAINFALL RESULTING FROM LAST NIGHTS THUNDERSTORMS HAS CAUSED
FLOODING FROM LEE COUNTY ILLINOIS...SOUTHEASTWARD THROUGH THE
PONTIAC AREA.  OVER 5 INCHES OF RAIN WAS REPORTED THROUGH EARLY
THIS MORNING IN THESE AREAS.

DUE TO THE POTENTIAL FOR ADDITIONAL THUNDERSTORM DEVELOPMENT THIS
AFTERNOON AND TONIGHT...THE FLASH FLOOD WATCH FOR SOUTHERN AND
WESTERN PORTIONS OF THE OUTLOOK AREA HAS BEEN EXTENDED UNTIL 7AM
THURSDAY.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THUNDERSTORMS WILL LIKELY BE ONGOING SOUTH OF THE KANKAKEE AND
ILLINOIS RIVERS THURSDAY MORNING...WITH A CHANCE OF MORNING
THUNDERSTORMS NORTH.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TONIGHT. MEASUREMENTS OF HEAVY
RAINFALL OR REPORTS OF FLOODING WOULD BE APPRECIATED.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO

LMZ740>745-766-190930-
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 OPEN WATERS FROM WINTHROP HARBOR IL EASTWARD TO THE
MID POINT OF THE LAKE AND SOUTHWARD TO MICHIGAN CITY MI BEYOND 5 NM
OFFSHORE-
400 PM CDT WED JUL 18 2007

THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS
AND INDIANA WATERS OF LAKE MICHIGAN.

.DAY ONE...TONIGHT.

THUNDERSTORMS ARE LIKELY TONIGHT.  SOME OF THESE STORMS MAY BE
SEVERE WITH WIND GUSTS IN EXCESS OF 34 KNOTS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

HAZARDOUS WINDS AND WAVES FOR SMALL CRAFT ARE EXPECTED TO DEVELOP BY
THURSDAY AFTERNOON...AND CONTINUE INTO FRIDAY.  NORTH WINDS
SUSTAINED AROUND 25 KNOTS WILL LIKELY RESULT IN WAVES IN EXCESS OF 6
FEET AND AN INCREASED THREAT OF RIP CURRENTS ALONG THE INDIANA
SHORELINE.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO

KL

In the hours before

Local storm report, Jul 18, 3:52 PM CST, 2 hours 30 minutes before

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
452 PM CDT WED JUL 18 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1207 AM     TSTM WND DMG     POLO                    41.98N 89.58W
07/18/2007                   OGLE               IL   AMATEUR RADIO

            3 TO 4 INCH TREE BRANCHES DOWN

1217 AM     TSTM WND DMG     DIXON                   41.85N 89.48W
07/18/2007                   LEE                IL   LAW ENFORCEMENT

            TREE DOWN AT 9TH AND HIGHLAND...RADAR TIME ESTIMATED

1245 AM     FLASH FLOOD      POLO                    41.98N 89.58W
07/18/2007                   OGLE               IL   AMATEUR RADIO

            DIVISION AND WEST COVEN STREETS FLOODED - 2 INCHES OF
            RAIN IN POLO SINCE BEGINNING OF STORM

0126 AM     FLOOD            5 E POLO                41.98N 89.48W
07/18/2007                   OGLE               IL   AMATEUR RADIO

            PINE CREEK OVER ITS BANKS IN WHITE PINES STATE PARK.
            FLOODING IN PARK IS BEGINNING.

0126 AM     TSTM WND DMG     5 E POLO                41.98N 89.48W
07/18/2007                   OGLE               IL   AMATEUR RADIO

            LARGE TREE BRANCH BLOWN DOWN NEAR THE ENTRANCE OF WHITE
            PINES STATE PARK

0130 AM     FLOOD            DIXON                   41.85N 89.48W
07/18/2007                   LEE                IL   LAW ENFORCEMENT

            FLOODING OFF OF ROUTE 2 ON THE NORTHEAST SIDE OF DIXON

0130 AM     FLASH FLOOD      AMBOY                   41.72N 89.33W
07/18/2007                   LEE                IL   LAW ENFORCEMENT

            WATER COMING UP THROUGH THE STORM DRAINS IN THE
            ROADWAYS...PER LEE COUNTY SHERIFFS OFFICE

0355 AM     TSTM WND DMG     PAXTON                  40.46N 88.10W
07/18/2007                   FORD               IL   LAW ENFORCEMENT

            LARGE TREE LIMBS BLOWN DOWN.

0700 AM     HEAVY RAIN       PERU                    41.34N 89.13W
07/18/2007  M3.05 INCH       LA SALLE           IL   TRAINED SPOTTER

0700 AM     HEAVY RAIN       5 NNE CORNELL           41.06N 88.69W
07/18/2007  M3.40 INCH       LIVINGSTON         IL   TRAINED SPOTTER

0700 AM     HEAVY RAIN       DIXON                   41.85N 89.48W
07/18/2007  M4.36 INCH       LEE                IL   CO-OP OBSERVER

0700 AM     HEAVY RAIN       3 NW DIXON              41.88N 89.52W
07/18/2007  M4.08 INCH       LEE                IL   TRAINED SPOTTER

0700 AM     HEAVY RAIN       POLO                    41.98N 89.58W
07/18/2007  M3.85 INCH       OGLE               IL   CO-OP OBSERVER

0700 AM     HEAVY RAIN       1 N MENDOTA             41.57N 89.12W
07/18/2007  M3.18 INCH       LA SALLE           IL   TRAINED SPOTTER

0700 AM     HEAVY RAIN       1 SE PONTIAC            40.87N 88.63W
07/18/2007  M2.95 INCH       LIVINGSTON         IL   TRAINED SPOTTER

0700 AM     HEAVY RAIN       1 E OREGON              42.01N 89.32W
07/18/2007  M2.87 INCH       OGLE               IL   TRAINED SPOTTER

0700 AM     HEAVY RAIN       DIXON                   41.85N 89.48W
07/18/2007  M4.36 INCH       LEE                IL   CO-OP OBSERVER

0700 AM     HEAVY RAIN       POLO                    41.98N 89.58W
07/18/2007  M4.27 INCH       OGLE               IL   TRAINED SPOTTER

0721 AM     FLASH FLOOD      3 E PONTIAC             40.88N 88.58W
07/18/2007                   LIVINGSTON         IL   LAW ENFORCEMENT

            WATER FLOWING ACROSS IL ROUTE 116

0755 AM     FLASH FLOOD      7 NW PONTIAC            40.95N 88.74W
07/18/2007                   LIVINGSTON         IL   EMERGENCY MNGR

            WATER COVERING ROADWAYS

0755 AM     FLASH FLOOD      5 S PONTIAC             40.80N 88.64W
07/18/2007                   LIVINGSTON         IL   EMERGENCY MNGR

            WATER COVERING ROADWAYS

0801 AM     HEAVY RAIN       3 S OREGON              41.97N 89.34W
07/18/2007  M5.19 INCH       OGLE               IL   CO-OP OBSERVER

0830 AM     HEAVY RAIN       1 ESE STREATOR          41.12N 88.81W
07/18/2007  M2.55 INCH       LA SALLE           IL   TRAINED SPOTTER

            PRECIPITATION RECORDED SINCE MIDNIGHT. DRY CREEK BED HAS
            RISEN TO 16 INCHES OF FLOWING WATER. COCORAH OBSERVER.

0425 PM     FLOOD            SAUNEMIN                40.89N 88.41W
07/18/2007                   LIVINGSTON         IL   LAW ENFORCEMENT

            ROADS REMAIN FLOODED ON WEST SIDE OF TOWN NEAR CEMETARY.

0425 PM     FLOOD            PONTIAC                 40.88N 88.64W
07/18/2007                   LIVINGSTON         IL   LAW ENFORCEMENT

            VEHICLE REMAINS SUBMERGED IN FLOOD WATERS ON NORTHEAST
            SIDE OF TOWN.

&&

The radar

The Milwaukee radar (KMKX), 72 km away, was scanning. The volume nearest the first event began at 00:22 UTC.

Open the radar archive at this moment

Event by event

21 thunderstorm wind, 6 flood, 5 flash flood, 5 heavy rain, 1 hail. Local standard time, as filed.

Thunderstorm Wind, McHenry

When: July 18, 6:22 PM CST
Where: McHenry County, Woodstock
Measured: 58 kt (67 mph) measured gust
Reported by: Trained Spotter
Coordinates: 42.320, -88.450

A gust to 67 mph was measured.

Thunderstorm Wind, Winnebago

When: July 18, 6:28 PM CST
Where: Winnebago County, Durand
Measured: 50 kt (58 mph) estimated gust
Reported by: Emergency Manager
Coordinates: 42.430, -89.330

Two trees blown down.

Thunderstorm Wind, McHenry

When: July 18, 6:30 PM CST
Where: McHenry County, Woodstock
Measured: 50 kt (58 mph) estimated gust
Reported by: Law Enforcement
Coordinates: 42.320, -88.450

A tree was blown down.

Thunderstorm Wind, Lake

When: July 18, 6:30 PM CST
Where: Lake County, Fox Lake
Measured: 50 kt (58 mph) estimated gust
Reported by: Newspaper
Coordinates: 42.400, -88.170

Several trees were blown down onto roads.

Thunderstorm Wind, McHenry

When: July 18, 6:34 PM CST
Where: McHenry County, Woodstock
Measured: 52 kt (60 mph) measured gust
Reported by: Trained Spotter
Coordinates: 42.320, -88.450

A gust to 60 mph was measured near Route 47 and Lucus.

Flash Flood, Winnebago

When: July 18, 6:52 PM CST to 9:00 PM CST
Where: Winnebago County, Roscoe
Cause: Heavy Rain
Reported by: Trained Spotter
Coordinates: 42.420, -89.020

East Rock Road closed due to flooding.

Flash Flood, Winnebago

When: July 18, 6:58 PM CST to 9:00 PM CST
Where: Winnebago County, South Beloit
Cause: Heavy Rain
Reported by: Law Enforcement
Coordinates: 42.480, -89.030

Blackhawk Road closed due to flooding.

Thunderstorm Wind, Kane

When: July 18, 7:20 PM CST
Where: Kane County, West Dundee
Measured: 50 kt (58 mph) estimated gust
Reported by: Emergency Manager
Coordinates: 42.100, -88.280

Trees were blown down.

Hail, Cook

When: July 18, 7:29 PM CST to 7:31 PM CST
Where: Cook County, Schaumburg
Measured: 1 in hail
Reported by: Public
Coordinates: 42.030, -88.080

Nickel to quarter size hail reported.

Heavy Rain, Kane

When: July 18, 7:35 PM CST to 7:55 PM CST
Where: Kane County, South Elgin
Reported by: Trained Spotter
Coordinates: 42.000, -88.280

One inch of rain in 20 minutes.

Thunderstorm Wind, Cook

When: July 18, 7:38 PM CST
Where: Cook County, Arlington Hgts
Measured: 50 kt (58 mph) estimated gust
Reported by: Law Enforcement
Coordinates: 42.080, -88.000

A tree was blown down blocking a road.

Thunderstorm Wind, Du Page

When: July 18, 7:40 PM CST
Where: Du Page County, Bensenville
Measured: 52 kt (60 mph) estimated gust
Reported by: Emergency Manager
Coordinates: 41.950, -87.930

A gust to 60 mph estimated at Route 83 and Thorndale.

Thunderstorm Wind, Cook

When: July 18, 7:44 PM CST
Where: Cook County, Mt Prospect
Measured: 50 kt (58 mph) estimated gust
Reported by: Law Enforcement
Coordinates: 42.070, -87.930

A tree was blown down blocking a road.

Heavy Rain, McHenry

When: July 18, 7:50 PM CST to 9:00 PM CST
Where: McHenry County, Crystal Lake
Reported by: Trained Spotter
Coordinates: 42.230, -88.330

Storm total rainfall 2.40 inches with minor ponding of water on roads.

Flood, Du Page

When: July 18, 8:00 PM CST to 10:00 PM CST
Where: Du Page County, West Chicago
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 41.880, -88.200

Four to five inches of standing water Route 59 and Route 64.

Thunderstorm Wind, Kendall

When: July 18, 8:10 PM CST
Where: Kendall County, Boulder Hill
Measured: 50 kt (58 mph) estimated gust
Reported by: Emergency Manager
Coordinates: 41.720, -88.350

Six inch diameter tree limbs blown down.

Heavy Rain, Cook

When: July 18, 8:11 PM CST to 8:41 PM CST
Where: Cook County, Palos Hgts
Reported by: Trained Spotter
Coordinates: 41.670, -87.800

Two inches of rain in 30 minutes near 135th and Ridgeland.

Thunderstorm Wind, Du Page

When: July 18, 8:18 PM CST
Where: Du Page County, Winfield
Measured: 50 kt (58 mph) estimated gust
Reported by: COOP Observer
Coordinates: 41.870, -88.170

A 10 inch diameter tree limb was blown down.

Heavy Rain, Cook

When: July 18, 8:20 PM CST
Where: Cook County, Chicago
Reported by: Public
Coordinates: 41.830, -87.650

Two inches of rain measured in Wrigleyville.

Thunderstorm Wind, Du Page

When: July 18, 8:21 PM CST
Where: Du Page County, West Chicago
Measured: 50 kt (58 mph) estimated gust
Reported by: Emergency Manager
Coordinates: 41.880, -88.200

One foot diameter tree blown down.

Thunderstorm Wind, Lee

When: July 18, 8:23 PM CST
Where: Lee County, 4 mi W of Amboy
Measured: 50 kt (58 mph) estimated gust
Reported by: Law Enforcement
Coordinates: 41.720, -89.407

A tree was blown down near Route 26 and Sterling Road.

Thunderstorm Wind, Will

When: July 18, 8:25 PM CST
Where: Will County, Romeoville
Measured: 53 kt (61 mph) estimated gust
Reported by: Official NWS Observations
Coordinates: 41.630, -88.070

A gust to 61 mph was measured at the National Weather Service Office.

Thunderstorm Wind, Kendall

When: July 18, 8:27 PM CST
Where: Kendall County, 1 mi N of Yorkville
Measured: 50 kt (58 mph) estimated gust
Reported by: Emergency Manager
Coordinates: 41.645, -88.450

Numerous trees blown down near Route 47 and Kennedy.

Thunderstorm Wind, Ogle

When: July 18, 8:30 PM CST
Where: Ogle County, Kings
Measured: 50 kt (58 mph) estimated gust
Reported by: Law Enforcement
Coordinates: 42.000, -89.100

A tree was blown onto Route 64 near Kings.

Thunderstorm Wind, Will

When: July 18, 8:30 PM CST
Where: Will County, Romeoville
Measured: 52 kt (60 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 41.630, -88.070

A gust to 60 mph was measured at 135th and Macon.

Flash Flood, Du Page

When: July 18, 8:31 PM CST to 11:00 PM CST
Where: Du Page County, Naperville
Cause: Heavy Rain
Reported by: Public
Coordinates: 41.780, -88.150

Water up to 3 feet deep on Naper Blvd, one mile south of 75th.

Flood, Lake

When: July 18, 8:32 PM CST to 11:00 PM CST
Where: Lake County, Lake Bluff
Cause: Heavy Rain
Reported by: Law Enforcement
Coordinates: 42.280, -87.830

Two feet of standing water at Route 41 and Route 176.

Thunderstorm Wind, Ogle

When: July 18, 8:35 PM CST
Where: Ogle County, Oregon
Measured: 50 kt (58 mph) estimated gust
Reported by: Law Enforcement
Coordinates: 42.020, -89.330

A tree was blown down just south of Oregon on Route 2.

Flood, Ogle

When: July 18, 8:37 PM CST
Where: Ogle County, Rochelle
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 41.920, -89.070

Water bumper deep on Capron Road. Rochelle measured 2.75 inches of rain.

Thunderstorm Wind, Lee

When: July 18, 8:45 PM CST
Where: Lee County, 3 mi S of West Brooklyn
Measured: 50 kt (58 mph) estimated gust
Reported by: Law Enforcement
Coordinates: 41.657, -89.150

A tree was blown down at Route 251 and Cottage Hill.

Flash Flood, Kane

When: July 18, 8:45 PM CST to 11:00 PM CST
Where: Kane County, Aurora
Cause: Heavy Rain
Reported by: Trained Spotter
Coordinates: 41.770, -88.320

Four to six inches of flowing water at Middle Avenue and Second Street. Aurora measured 2.07 inches of rain.

Flood, Cook

When: July 18, 8:55 PM CST to 11:00 PM CST
Where: Cook County, Oak Forest
Cause: Heavy Rain
Reported by: Trained Spotter
Coordinates: 41.600, -87.750

Four to five inches of standing water at 167th and Cicero.

Flash Flood, Cook

When: July 18, 9:00 PM CST to July 19, 12:00 AM CST
Where: Cook County, Oak Forest
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 41.600, -87.750

A viaduct was flooded west of Cicero Avenue on 159th Street.

Flood, Kendall

When: July 18, 9:09 PM CST to July 19, 12:00 AM CST
Where: Kendall County, Oswego
Cause: Heavy Rain
Reported by: Trained Spotter
Coordinates: 41.680, -88.350

Four inches of flowing water at Simmom and Douglas Roads. Simmon flooded for one half mile. Eight inches of standing water at Dolores and Route 31.

Flood, Will

When: July 18, 9:23 PM CST to 11:30 PM CST
Where: Will County, Joliet
Cause: Heavy Rain
Reported by: Trained Spotter
Coordinates: 41.530, -88.100

Two and two and a half feet of water at Richards and Washington Streets. Water one foot deep at Center Street, north of Interstate 80.

Thunderstorm Wind, Du Page

When: July 18, 10:45 PM CST
Where: Du Page County, Wayne
Measured: 50 kt (58 mph) estimated gust
Reported by: Law Enforcement
Coordinates: 41.950, -88.250

A tree was blown down on Shagbark Road.

Thunderstorm Wind, Kane

When: July 18, 11:08 PM CST
Where: Kane County, St Charles
Measured: 50 kt (58 mph) estimated gust
Reported by: Law Enforcement
Coordinates: 41.920, -88.320

A tree was blown down near Blackhawk and Joseph Roads.

Heavy Rain, Will

When: July 19, 12:00 AM CST
Where: Will County, Plainfield to Romeoville
Reported by: Official NWS Observations
Coordinates: 41.600, -88.200

Storm total rainfall of 4.03 inches measured in Plainfield near Route 126 and Route 30. Storm total rainfall of 3.03 inches measured at the National Weather Service office.

What these are

Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.
Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Illinois in 2007 Every state in 2007 This day in weather history Warnings in Illinois, July 2007

Sources

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: 49698, 49670, 49671, 52290, 49699, 49705, 49706, 49672, 49669, 49723, 49673, 49674, 49675, 49722, 49711, 49676, 49727, 52440, 49725, 49702, 49678, 49700, 49679, 49681, 49701, 49720, 49728, 49694, 49721, 49695, 49718, 49714, 49717, 49715, 49716, 49696, 49697, 49726.