863
NOUS43 KLOT 130110
PNSLOT
ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-131315-
PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE CHICAGO IL
810 PM CDT WED AUG 12 2026 /910 PM EDT WED AUG 12 2026/
..NWS DAMAGE SURVEY FOR 08/11/2026 DERECHO
DURING THE EARLY MORNING HOURS ON TUESDAY, AUGUST 11TH,
THUNDERSTORMS ERUPTED ACROSS EASTERN IOWA. THESE STORMS QUICKLY
INTENSIFIED AS THEY CROSSED INTO NORTHERN ILLINOIS AND ORGANIZED
INTO A SEVERE SQUALL LINE WHICH RACED ACROSS THE REGION THROUGH
MIDDAY. THIS THUNDERSTORM COMPLEX--CLASSIFIED AS A DERECHO DUE TO
THE WIDESPREAD, CONTINUOUS, AND LONG-LIVED NATURE OF SEVERE WIND
GUSTS--CAUSED EXTENSIVE DAMAGE ACROSS THE NWS CHICAGO SERVICE
AREA. NUMEROUS WIND GUSTS OF 70 TO 90 MPH WERE RECORDED ACROSS
PARTS OF SOUTHERN KANE, DUPAGE, WILL, SOUTHERN COOK, KANKAKEE,
AND LAKE (IN) COUNTIES, WITH A PEAK MEASURED GUST OF 99 MPH
RECORDED AT THE GARY/CHICAGO INTERNATIONAL AIRPORT. THESE
STRAIGHT-LINE THUNDERSTORM WINDS CAUSED EXTENSIVE DAMAGE ACROSS
PARTS OF THE WESTERN AND SOUTHERN CHICAGO SUBURBS AND INTO
NORTHWEST INDIANA. FINALLY, AT LEAST FIVE TORNADOES OCCURRED WITH
THIS DERECHO.
OSWEGO
RATING: EF0
ESTIMATED PEAK WIND: 75 MPH
PATH LENGTH /STATUTE/: 5.19 MILES
PATH WIDTH /MAXIMUM/: 150 YARDS
FATALITIES: 0
INJURIES: 0
START DATE: 08/11/2026
START TIME: 10:14 AM CDT
START LOCATION: 3 NE YORKVILLE / KENDALL COUNTY / IL
START LAT/LON: 41.6782 / -88.4008
END DATE: 08/11/2026
END TIME: 10:20 AM CDT
END LOCATION: 3 SSE OSWEGO / KENDALL COUNTY / IL
END LAT/LON: 41.6555 / -88.3078
SURVEY SUMMARY:
THIS TORNADO BEGAN NEAR US ROUTE 34 AND AMERICAN WAY AND THEN
CROSSED THE FOX RIVER. IT CONTINUED IN A GENERALLY SOUTHEASTERLY
DIRECTION CAUSING INTERMITTENT TREE DAMAGE AS IT CROSSED THROUGH
SEVERAL SUBDIVISIONS IN THE VICINITY OF GROVE ROAD. THE TORNADO
APPEARS TO HAVE LIFTED NEAR DOUGLAS ROAD JUST SOUTH OF COLLINS
ROAD.
WILMINGTON
RATING: EF1
ESTIMATED PEAK WIND: 90 MPH
PATH LENGTH /STATUTE/: 1.52 MILES
PATH WIDTH /MAXIMUM/: 150 YARDS
FATALITIES: 0
INJURIES: 0
START DATE: 08/11/2026
START TIME: 10:37 AM CDT
START LOCATION: 1 NNE WILMINGTON / WILL COUNTY / IL
START LAT/LON: 41.3064 / -88.1558
END DATE: 08/11/2026
END TIME: 10:39 AM CDT
END LOCATION: 1 ENE WILMINGTON / WILL COUNTY / IL
END LAT/LON: 41.3003 / -88.1309
SURVEY SUMMARY:
THIS TORNADO STARTED NEAR W BALTIMORE STREET AND N 1ST STREET
WHERE IT REMOVED PART OF THE ROOF OF AN AUTOMOTIVE REPAIR SHOP
AND TOSSED IT INTO THE SIDE OF AN ADJACENT STRIP MALL. DAMAGE IN
THIS AREA WAS CONSISTENT WITH PEAK WINDS NEAR 90 MPH. THE TORNADO
THEN CROSSED THE KANKAKEE RIVER AND SUBSEQUENTLY TRACKED ACROSS
THE OAKWOOD CEMETERY WHERE IT CAUSED SUBSTANTIAL TREE DAMAGE,
AGAIN CONSISTENT WITH WINDS NEAR 90 MPH. THE TORNADO THEN TRACKED
EAST ALONG RIDGE STREET BEFORE LIFTING NEAR THE FORKED CREEK
PRESERVE.
MOKENA - TINLEY PARK
RATING: EF1
ESTIMATED PEAK WIND: 95 MPH
PATH LENGTH /STATUTE/: 7.60 MILES
PATH WIDTH /MAXIMUM/: 200 YARDS
FATALITIES: 0
INJURIES: 0
START DATE: 08/11/2026
START TIME: 10:39 AM CDT
START LOCATION: 2 NNE NEW LENOX / WILL COUNTY / IL
START LAT/LON: 41.5487 / -87.9589
END DATE: 08/11/2026
END TIME: 10:46 AM CDT
END LOCATION: 1 NW FRANKFORT SQUARE / WILL COUNTY / IL
END LAT/LON: 41.5336 / -87.8167
SURVEY SUMMARY:
THIS TORNADO BEGAN NEAR W. MAPLE AND BLODGETT ROADS AND THEN
CROSSED I-80 NEAR MILE MARKER 141. THE TORNADO CONTINUED IN A
SOUTHEASTERLY DIRECTION, CAUSING MAINLY MINOR TREE DAMAGE AS IT
ROUGHLY PARALLELED W REGAN ROAD AND 195TH STREET. THE TORNADO
REACHED ITS PEAK INTENSITY IN A SUBDIVISION NEAR ST. MARY'S
CATHOLIC CHURCH WHERE SEVERAL RESIDENCES SUSTAINED SHINGLE AND
SOFFIT DAMAGE AND LARGE HARDWOOD TREES WERE SNAPPED, CONSISTENT
WITH PEAK WINDS OF 85 TO 95 MPH. THE TORNADO THEN CONTINUED EAST
ROUGHLY ALONG 195TH STREET BEFORE LIFTING JUST NORTH OF THE HILDA
WALKER INTERMEDIATE SCHOOL.
ORLAND PARK TO MUNSTER
RATING: EF1
ESTIMATED PEAK WIND: 105 MPH
PATH LENGTH /STATUTE/: 22.40 MILES
PATH WIDTH /MAXIMUM/: 300 YARDS
FATALITIES: 0
INJURIES: 0
START DATE: 08/11/2026
START TIME: 10:41 AM CDT
START LOCATION: 3 NNW MOKENA / COOK COUNTY / IL
START LAT/LON: 41.5738 / -87.9057
END DATE: 08/11/2026
END TIME: 10:59 AM CDT
END LOCATION: 2 N MUNSTER / LAKE COUNTY / IN
END LAT/LON: 41.5772 / -87.5004
SURVEY SUMMARY:
THE TORNADO BEGAN JUST EAST OF THE WILL COOK COUNTY LINE IN THE
BROOK HILL SUBDIVISION AND MOVED RAPIDLY EAST AND SOUTHEASTWARD
ACROSS SOUTHERN PORTIONS OF ORLAND PARK AND TINLEY PARK RESULTING
IN CONSIDERABLE DAMAGE TO TREES AND POWER LINES. SOME STRUCTURAL
DAMAGE TO SEVERAL BUILDINGS WAS NOTED ALONG 183RD ST IN TINLEY
PARK. THE TORNADO THEN CROSSED INTERSTATES 80 AND 57 BEFORE
MOVING ACROSS COUNTRY CLUB HILLS AND FLOSSMOOR AND GLENWOOD WHERE
THE MOST SUBSTANTIAL TREE DAMAGE WAS NOTED WITH NUMEROUS LARGE
TREES SNAPPED OR UPROOTED ALONG THE PATH. SOME TREES FELL INTO
BUILDINGS AND ONTO CARS CAUSING SIGNIFICANT DAMAGE. THE TORNADO
CROSSED THE BISHOP FORD EXPRESSWAY AND MOVED ACROSS LANSING WHERE
IT CONTINUED TO PRODUCE CONSIDERABLE TREE DAMAGE. THE TORNADO
CROSSED THE STATE LINE JUST NORTH OF RIDGE RD AND CONTINUED TO
PRODUCE CONSIDERABLE TREE DAMAGE INTO MUNSTER BEFORE TURNING
NORTH AND DISSIPATING SHORTLY AFTER CROSSING I-80 JUST EAST OF
CALUMET AVE.
MONEE TO ST JOHN
RATING: EF2
ESTIMATED PEAK WIND: 115 MPH
PATH LENGTH /STATUTE/: 25.75 MILES
PATH WIDTH /MAXIMUM/: 300 YARDS
FATALITIES: 0
INJURIES: 0
START DATE: 08/11/2026
START TIME: 10:43 AM CDT
START LOCATION: 5 SSW FRANKFORT / WILL COUNTY / IL
START LAT/LON: 41.4284 / -87.8833
END DATE: 08/11/2026
END TIME: 11:02 AM CDT
END LOCATION: 2 WNW CROWN POINT / LAKE COUNTY / IN
END LAT/LON: 41.4385 / -87.3914
SURVEY SUMMARY:
TO BE ADDED LATER.
.WILL-SOUTHERN COOK-LAKE (IN)-PORTER COUNTY STRAIGHT-LINE WINDS
EXTENSIVE STRAIGHT-LINE THUNDERSTORM WIND DAMAGE OCCURRED IN
ASSOCIATION WITH WIDESPREAD 70 TO LOCALLY NEAR 100 MPH WIND
GUSTS. ADDITIONAL INFORMATION WILL BE PROVIDED IN FORTHCOMING
PUBLIC INFORMATION STATEMENT UPDATES.
EF SCALE: THE ENHANCED FUJITA SCALE CLASSIFIES TORNADOES INTO THE
FOLLOWING CATEGORIES:
EF0.....65 TO 85 MPH
EF1.....86 TO 110 MPH
EF2.....111 TO 135 MPH
EF3.....136 TO 165 MPH
EF4.....166 TO 200 MPH
EF5.....>200 MPH
NOTE:
THE INFORMATION IN THIS STATEMENT IS PRELIMINARY AND SUBJECT TO
CHANGE PENDING FINAL REVIEW OF THE EVENTS AND PUBLICATION IN
NWS STORM DATA.
NWS CHICAGO
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