Strong to severe thunderstorms moved across portions of northern Illinois during the afternoon of September 3rd.
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 to severe thunderstorms moved across portions of northern Illinois during the afternoon of September 3rd.
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 Sep 3, 11:47 AM CST, 23 minutes earlier.
Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 1247 PM CDT Mon Sep 3 2018 .UPDATE... 1113 AM CDT Monitoring thunderstorm trends in the near term, with additional thunderstorm development expected this afternoon into the evening. Outside of areas in far northwest IL, along/west of I-39, mainly dry conditions have been in place over the last couple of hours. Several hours of warming in a very moist environment has allowed instability to build and CIN to erode, with low level lapse rates increasing. Despite upper level ridge building across the region, will see mid level energy ride across the region this afternoon. This increasing ascent and instability with some focus in the lower levels should allow thunderstorm development to occur this afternoon. Initial coverage here in the near term will likely remain low, however, do expect coverage to increase through mid afternoon across much of northern IL and northwest IN. Thunderstorms are likely, especially north of I-80, with isolated to widely scattered thunderstorms south. Lowering bulk shear and weak mid level lapse rates should limit any severe threat, though a few stronger storms with gusty winds are possible. Flooding is possible, especially near the Illinois and Wisconsin state line. Rodriguez && .SHORT TERM... 329 AM CDT Through tonight... Main concern for today and tonight will continue to be thunderstorms chances and precipitation amounts. For the remainder of the overnight hours, have been monitoring continued development of scattered showers and thunderstorms across northern Illinois. The main focus for the continued development looks to be a broad zone of isentropic lift and weak shortwave activity rippling through a belt of fast swly flow aloft. The longwave pattern has varied little over the past few days, though the main focus continues to shift slightly northwest as the center of the Bermuda High sits centered over the Mid-Atlantic region with gradually building ridging extending across the Middle Mississippi Valley. The short range guidance continues to advertise slight height rises over the local area, which support the idea of the focus of the most organized convective activity to be slightly to the north and west of that observed over the past couple days. However, there will still be enough broad instability and moisture, with both the DVN and ILX 03/00Z soundings indicating 1.75 inch pwats and the short range guidance indicating 2-3k J/kg CAPE, that periods of showers and thunderstorms will be possible. While widespread cloud cover and weak forcing will minimize any severe threat, localized heavy rain will be a concern. Locations north of the I-88 corridor will need to be monitored closely for flooding potential since that area received anywhere from 3 to 7 inches of rain yesterday and that area remains under a Slight Risk for Excessive rainfall per the latest WPC Outlook. The exact details of convective activity today remain somewhat uncertain except that the main area impacted should be generally north of the I-80 corridor, but given that any residual outflow boundaries or differential heating boundaries could provide enough sfc forcing for at least isold-sct tsra, even the srn portions of the CWA can't be ruled out. The temperature forecast for today will also have some bust potential. Currently, expect that much of the area along and south of I-80 should peg 90 F with lower temps to the north under more extensive cloud cover. However, should the cloud cover become thicker and more extensive over the srn locations, the 90 F mark could be hard to hit. However, the screaming is that this Labor Day should be warm and humid with showers and thunderstorms likely over the northern portions of the CWA and a lower chance for pcpn to the south. && .LONG TERM... 236 AM CDT Tuesday through Sunday... Overview...The active pattern continues through the extended with multiple chances for showers and storms. Hot and humid conditions also continue through Wednesday, but a cold front brings cooler temps to the region for the latter half of the week. Isolated afternoon storms are possible Tuesday, but I have low confidence in coverage and timing. I have higher confidence in hot and humid conditions resulting in heat indices in the mid to upper 90s. Afternoon storms should dissipate as the sun goes down. The next chance of precip arrives ahead of a cold front Wednesday morning. I have high confidence in rain across the area. Given the slow nature of the front, I think heat indices will once again be in the 90s. Luckily a cooler air mass follows the cold front with highs only in the 70s to around 80 Thursday. Guidance continues to indicate showers and some storms are possible mainly along and south of I-80 Thursday into Friday morning thanks to an upper level wave over northern IL. I have medium coverage in precip and thunder occurrence. Precip chances increase across the forecast area Saturday as an upper level wave and surface low move over the region. I have much higher confidence in precip Saturday than Sunday. Sunday may be dry, but I left low chance precip chances as some models have the low traveling a bit slower. Zonal flow aloft would suggest the active yet cooler pattern continues as waves pass over the region early next week. JEE && .AVIATION... For the 18Z TAFs... An active weather period likely this afternoon through this evening, with thunderstorms expected across all of the terminals. Have seen thunderstorm development quickly occur early this afternoon across much of northern IL and northwest IN, in a very warm and moist environment. Expect the coverage of these storms to remain the same over the next several hours, with generally higher coverage expected for areas along/north of I-80. A few stronger storms are possible with gusty winds possible, and with heavy rain significantly reducing vis likely. Should see thunderstorm coverage lower early this evening, with focus shifting further to the north into southern WI late this evening. Ceilings should remain VFR, however, any stronger storm could briefly lower ceilings to MVFR. Winds will remain a challenge this afternoon for the ORD/MDW/GYY terminals where thunderstorm outflow and lake breeze interaction will likely cause varying winds this afternoon into the evening. Rodriguez && .MARINE... 236 AM CDT A cold front will push south down the lake today and stall over the middle of the lake early this afternoon. A lake breeze will likely push on shore this afternoon. High pressure builds over Lake Superior this afternoon, and as it continues east, east winds increase to 10-20 kt over the northern end of the lake. A period of south winds of 15-25 kt begins Tuesday. Winds sharply turn north 10-20 kt, psbly to 25 kt behind a cold front Wednesday. A small craft advisory may be needed for hazardous waves Wednesday night into Thursday morning. Northeast winds diminish as a high builds over the western lakes Thursday. Northeast to east winds are expected through at least the first half of the weekend. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Hazardous Weather Outlook...CORRECTED
National Weather Service Chicago/Romeoville IL
1141 AM CDT Mon Sep 3 2018
ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
041630-
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-DeKalb-Kane-DuPage-Cook-
La Salle-Kendall-Grundy-Will-Kankakee-Livingston-Iroquois-Ford-
Lake IN-Porter-Newton-Jasper-Benton-
1141 AM CDT Mon Sep 3 2018 /1241 PM EDT Mon Sep 3 2018/
This Hazardous Weather Outlook is for portions of North Central
Illinois...Northeast Illinois and Northwest Indiana.
.DAY ONE...Today and Tonight.
Weather hazards expected...
Significant Thunderstorm Risk...with an associated:
Limited damaging wind risk...up to 60 mph.
Elevated Flooding Risk.
Limited Excessive heat Risk.
DISCUSSION...
Additional thunderstorms are likely the rest of today into the
evening, especially north of I-80, with isolated to widely
scattered thunderstorms south. Flooding is possible, especially
near the Illinois and Wisconsin state line. Widespread severe
storms are not expected, though a few stronger storms with gusty
winds are possible. Hot and humid conditions also continue with
highest heat indices in the mid 90s.
Flooding is expected along portions of the Des Plaines, Fox,
Pecatonica, and Rock rivers.
.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.
Tuesday...
Limited Thunderstorm Risk.
Limited Excessive Heat Risk.
Wednesday...
Elevated Flooding Risk.
Elevated Thunderstorm Risk.
Limited Excessive Heat Risk.
High Swim Risk
Thursday through Saturday...
Limited Thunderstorm Risk.
High Swim Risk
Sunday...
Limited Thunderstorm Risk.
DISCUSSION:
There are periodic thunderstorm chances throughout the week. In
addition, hot and humid conditions are also expected into
Wednesday.
Flooding is expected along portions of the Des Plaines, Fox,
Pecatonica, and Rock rivers.
.SPOTTER INFORMATION STATEMENT...
Spotter activation will not be necessary through tonight.
GENERAL STORM MOTION OF THE DAY:
Moving toward the northeast 30 to 40 mph.
LMZ740>745-041630-
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-
1141 AM CDT Mon Sep 3 2018
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...Today and Tonight.
Weather hazards expected...
Significant Thunderstorm Risk.
.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.
Tuesday...
Limited Thunderstorm Risk.
Wednesday and Thursday...
Hazardous conditions for small craft are likely.
Limited Thunderstorm Risk.
Friday...
Limited Thunderstorm Risk.
Saturday and Sunday...
Hazardous conditions for small craft are likely.
Limited Thunderstorm Risk.
LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-041630-
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 Two 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 Holland to Whitehall MI 5 nm off shore to mid-
line of 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-
1141 AM CDT Mon Sep 3 2018
This Hazardous Weather Outlook is for portions of the open waters
of Lake Michigan.
.DAY ONE...Today and Tonight.
Weather hazards expected...
Significant Thunderstorm Risk.
.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.
Tuesday through Sunday...
Limited Thunderstorm Risk.
Rodriguez
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www.youtube.com/nwschicagoPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
756 AM CDT MON SEP 3 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0715 AM HEAVY RAIN 4 SSE LOVES PARK 42.28N 88.98W
09/03/2018 M1.72 INCH WINNEBAGO IL TRAINED SPOTTER
24 HOUR TOTAL NEAR TULIP AND TRAVERTINE IN ROCKFORD.
WEEKEND TOTAL IS 4.67 INCHES.
&&
RCPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
809 AM CDT MON SEP 3 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0728 AM HEAVY RAIN LIBERTYVILLE 42.28N 87.97W
09/03/2018 M2.25 INCH LAKE IL PUBLIC
24 HOUR RAINFALL TOTAL RELAYED VIA TWITTER. WEEKEND TOTAL
IS 4.53 INCHES.
&&
RCPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
832 AM CDT MON SEP 3 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0830 AM HEAVY RAIN WOODSTOCK 42.31N 88.44W
09/03/2018 M2.28 INCH MCHENRY IL CO-OP OBSERVER
24 HOUR RAINFALL TOTAL. RAINFALL TOTAL SINCE EARLY
SATURDAY IS 6.36 INCHES.
&&
RCPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1040 AM CDT MON SEP 3 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0840 AM HEAVY RAIN 3 WNW BULL VALLEY 42.33N 88.40W
09/03/2018 M2.45 INCH MCHENRY IL COCORAHS
RAINFALL SINCE 8AM ON 9/2.
0900 AM HEAVY RAIN 3 W LAKE IN THE HILLS 42.19N 88.38W
09/03/2018 M2.45 INCH MCHENRY IL COCORAHS
24 HOUR RAINFALL.
&&
KLUBERPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1217 PM CDT MON SEP 3 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1158 AM HEAVY RAIN SOMONAUK 41.63N 88.68W
09/03/2018 M1.00 INCH DE KALB IL TRAINED SPOTTER
RAINFALL IN 9 MINUTES AS OF REPORT TIME. ALSO A BRIEF
PERIOD OF WIND GUSTS ESTIMATED UP TO 50 MPH.
&&
RCThe Milwaukee radar (KMKX), 70 km away, was scanning. The volume nearest the first event began at 18:10 UTC.
4 flood, 4 funnel cloud, 4 thunderstorm wind, 3 lightning, 1 heavy rain, 1 flash flood, 1 tornado. Local standard time, as filed.
Water from retention ponds overflowed onto some streets with about 3 inches of standing flood waters.
A man was struck by lightning in Whalon Lake Forest Preserve and died a few days later.
A funnel cloud was observed in Mc Henry but did not reach the ground.
Wind gusts were estimated to 60 mph.
Rainfall of 1.25 inches was measured in 30 minutes.
Lightning struck a parapet brick wall on a two story apartment building producing only minor damage.
Heavy rain caused flooding inside portions of Terminal 5 at Chicago O'Hare Airport. Interstate 90, which is the entrance to O'Hare Airport, was closed in both directions due to significant flooding where Mannheim Road crosses the interstate and where the Canadian National Railway bridge crosses the interstate. Rainfall of 1.45 inches was measured at O'Hare Airport and 1.97 inches was measured nearby, 0.7 miles west northwest of Park Ridge.
A weak EF-0 tornado produced mainly tree damage in western Chicago. The first damage was noted on Arthington Street, just west of Cicero Avenue. A continuous path of mostly minor tree damage extended to the east northeast crossing Interstate 290 near Pulaski Road with the final damage noted near Garfield Park, between 5th Avenue and Jackson Blvd near Central Park Avenue. One tree was blown into an apartment building knocking out windows and a couple of large tree limbs fell onto cars.
A spotter recorded video of a funnel cloud extending three quarters of the way to the ground.
A house was struck by lightning and was damaged in the southern part of the Portage Park neighborhood.
Two large tree limbs were blown down in the Uptown neighborhood.
One large tree and one large tree limb were blown down near Clark and Montrose.
A brief funnel cloud was observed extending at least halfway to the ground.
Several large trees and tree limbs were blown down along with one utility pole. The damage was near and west of Powis Road and near and north of Army Trail Road.
A park was reported flooded in Roscoe.
Two spotters observed a funnel cloud in Rock Cut State Park, north of Harlem Road. After discussion with employees at the park, it was determined that this funnel cloud did not touch the ground.
Southbound Interstate 90 was reported flooded near the Jane Byrne Interchange.
About six inches of water was reported in the left lane of Interstate 57 near mile marker 351.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Lightning, Will | 2018-09-06 | 33 | Male | Outside/Open Areas | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2018Every state in 2018This day in weather historyThe tornado archive for Illinois, 2018Warnings in Illinois, September 2018
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: 785236, 785023, 785024, 785025, 785240, 785026, 785239, 785033, 785027, 785034, 785028, 785032, 785029, 785030, 785235, 785031, 785394, 785241.