799  
FLUS43 KLOT 181621  
HWOLOT  
 
HAZARDOUS WEATHER OUTLOOK  
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL  
1121 AM CDT MON AUG 18 2025  
 
ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-  
010-011-019-191630-  
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-  
1121 AM CDT MON AUG 18 2025 /1221 PM EDT MON AUG 18 2025/  
 
THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL  
ILLINOIS...NORTHEAST ILLINOIS AND NORTHWEST INDIANA.  
   
DAY ONE
 
THIS AFTERNOON AND TONIGHT.  
 
WEATHER HAZARDS EXPECTED...  
 
ELEVATED THUNDERSTORM RISK...WITH AN ASSOCIATED:  
LEVEL 2 OF 5 DAMAGING WIND RISK...UP TO 60 MPH.  
LEVEL 1 OF 5 TORNADO RISK  
ELEVATED FLOODING RISK...LEVEL 2 OUT OF 4.  
LIMITED EXCESSIVE HEAT RISK.  
HIGH SWIM RISK AT LAKE MICHIGAN BEACHES THROUGH MID AFTERNOON.  
 
DISCUSSION...  
 
HIGH WAVES AND DANGEROUS CURRENTS ARE EXPECTED AT LAKE MICHIGAN  
BEACHES THROUGH MID-AFTERNOON, ESPECIALLY FOR LAKE COUNTY AND  
NORTHERN COOK COUNTY.  
 
HOT AND HUMID CONDITIONS ARE EXPECTED TODAY WITH PEAK AFTERNOON  
HEAT INDICES NEAR OR JUST ABOVE 100 DEGREES AWAY FROM LAKE  
MICHIGAN.  
 
SHOWERS AND STORMS ARE EXPECTED THIS AFTERNOON AND EVENING. A FEW  
MAY BE SEVERE WITH DAMAGING WINDS AND TORRENTIAL DOWNPOURS. WITH  
SATURATED SOIL CONDITIONS, EVEN A BRIEF PERIOD OF INTENSE RAINFALL  
COULD LEAD TO A FLASH FLOODING SITUATION.  
   
DAYS TWO THROUGH SEVEN
 
TUESDAY THROUGH SUNDAY.  
 
TUESDAY...  
LIMITED THUNDERSTORM RISK, MAINLY SOUTHEAST OF I-55.  
   
SPOTTER INFORMATION STATEMENT
 
 
SPOTTERS MAY BE NEEDED THIS AFTERNOON AND EVENING.  
 
GENERAL STORM MOTION OF THE DAY:  
 
MOVING TOWARD THE EAST AT 25 MPH.  
 

 
 
LMZ740>745-191630-  
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-  
1121 AM 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
 
THIS AFTERNOON AND TONIGHT.  
 
WEATHER HAZARDS EXPECTED...  
 
HAZARDOUS CONDITIONS FOR SMALL CRAFT.  
ELEVATED THUNDERSTORM RISK...WITH AN ASSOCIATED:  
LEVEL 1 OF 5 THUNDERSTORM WIND GUST RISK...UP TO 50 KTS.  
   
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.  
 

 
 
LENNING  
 
VISIT US AT WWW.WEATHER.GOV/CHICAGO  
 
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