474  
FLUS43 KLOT 190236 AAA  
HWOLOT  
 
HAZARDOUS WEATHER OUTLOOK...UPDATED  
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL  
936 PM CDT MON AUG 18 2025  
 
ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-  
010-011-019-200245-  
WINNEBAGO-BOONE-MCHENRY-LAKE IL-OGLE-LEE-DE KALB-KANE-DUPAGE-  
LA SALLE-KENDALL-GRUNDY-KANKAKEE-LIVINGSTON-IROQUOIS-FORD-  
NORTHERN COOK-CENTRAL COOK-SOUTHERN COOK-NORTHERN WILL-  
SOUTHERN WILL-EASTERN WILL-LAKE IN-PORTER-NEWTON-JASPER-BENTON-  
936 PM CDT MON AUG 18 2025 /1036 PM EDT MON AUG 18 2025/  
 
THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL  
ILLINOIS...NORTHEAST ILLINOIS AND NORTHWEST INDIANA.  
   
DAY ONE
 
TONIGHT.  
 
WEATHER HAZARDS EXPECTED...  
 
ELEVATED THUNDERSTORM RISK...WITH AN ASSOCIATED:  
LEVEL 1 OF 5 DAMAGING WIND RISK...UP TO 60 MPH.  
ELEVATED FLOODING RISK.  
 
DISCUSSION...  
 
SCATTERED THUNDERSTORMS WILL CONTINUE TONIGHT, MAINLY ALONG AND  
SOUTH OF INTERSTATE 80, WHERE AN ISOLATED STRONG TO SEVERE  
THUNDERSTORM IS POSSIBLE.  
 
VERY HEAVY RAIN IS EXPECTED WITH THESE THUNDERSTORMS, WHICH MAY  
LEAD TO ADDITIONAL LOCALIZED FLASH FLOODING, ESPECIALLY IN URBAN  
AREAS.  
   
DAYS TWO THROUGH SEVEN
 
TUESDAY THROUGH SUNDAY.  
 
TUESDAY...  
LIMITED FLOODING RISK.  
LIMITED THUNDERSTORM RISK.  
WEDNESDAY...  
HIGH SWIM RISK AT LAKE MICHIGAN BEACHES.  
   
SPOTTER INFORMATION STATEMENT
 
 
SPOTTER REPORTS OF FLOODING WILL BE APPRECIATED.  
 
GENERAL STORM MOTION OF THE DAY:  
 
MOVING TOWARD THE EAST AT 20 TO 30 MPH.  
 

 
 
LMZ740>745-200245-  
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 TO BURNS HARBOR IN-  
BURNS HARBOR TO MICHIGAN CITY IN-  
936 PM CDT MON AUG 18 2025  
 
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.  
 
WEATHER HAZARDS EXPECTED...  
 
ELEVATED THUNDERSTORM RISK...WITH AN ASSOCIATED:  
LEVEL 1 OF 5 THUNDERSTORM WIND GUST RISK...UP TO 40 KNOTS.  
   
DAYS TWO THROUGH SEVEN
 
TUESDAY THROUGH SUNDAY.  
 
TUESDAY...  
HAZARDOUS CONDITIONS FOR SMALL CRAFT ARE LIKELY.  
LIMITED THUNDERSTORM RISK.  
WEDNESDAY...  
HAZARDOUS CONDITIONS FOR SMALL CRAFT ARE LIKELY.  
 

 
 
VISIT US AT WWW.WEATHER.GOV/CHICAGO  
 
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