450  
FLUS43 KLOT 200841  
HWOLOT  
 
HAZARDOUS WEATHER OUTLOOK  
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL  
341 AM CDT THU SEP 20 2018  
 
ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-  
210845-  
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-  
341 AM CDT THU SEP 20 2018 /441 AM EDT THU SEP 20 2018/  
 
THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL  
ILLINOIS...NORTHEAST ILLINOIS AND NORTHWEST INDIANA.  
   
DAY ONE
 
EARLY THIS MORNING THROUGH TONIGHT.  
 
WEATHER HAZARDS EXPECTED...  
 
ELEVATED THUNDERSTORM RISK.  
LIMITED EXCESSIVE HEAT RISK.  
 
DISCUSSION...  
 
SCATTERED THUNDERSTORMS ARE POSSIBLE EARLY THIS MORNING ACROSS  
FAR NORTHERN ILLINOIS, MAINLY NORTH OF THE INTERSTATE 88 CORRIDOR.  
SOME OF THESE STORMS MAY PRODUCE LOCALLY HEAVY RAINFALL NEAR THE  
WISCONSIN STATE LINE. ISOLATED THUNDERSTORMS ARE POSSIBLE ACROSS  
THE REMAINDER OF THE AREA TODAY, AS A WARM FRONT LIFTS ACROSS THE  
REGION. AS THE WARM FRONT LIFTS NORTH, TEMPERATURES WILL WARM TO  
AROUND 90 OR THE LOWER 90S IN MANY SPOTS, WITH HEAT INDEX VALUES  
PEAKING IN THE 94 TO 102 RANGE DURING THE WARMEST PART OF THE  
AFTERNOON. THERE IS AN ADDITIONAL CHANCE OF THUNDERSTORMS LATE  
TONIGHT AS A COLD FRONT MOVES THROUGH.  
   
DAYS TWO THROUGH SEVEN
 
FRIDAY THROUGH WEDNESDAY.  
 
FRIDAY...  
LIMITED THUNDERSTORM RISK.  
HIGH SWIM RISK  
SATURDAY...  
HIGH SWIM RISK  
MONDAY...  
LIMITED THUNDERSTORM RISK.  
TUESDAY...  
ELEVATED THUNDERSTORM RISK.  
 
DISCUSSION:  
 
SCATTERED THUNDERSTORMS WILL END FROM NORTHWEST TO SOUTHEAST  
ACROSS THE AREA FRIDAY, AS A COLD FRONT MOVES THROUGH THE AREA.  
GUSTY NORTH WINDS WILL DEVELOP LATER IN THE DAY AND CONTINUE  
FRIDAY NIGHT, WHICH WILL RESULT IN BUILDING WAVES AND DANGEROUS  
SWIM CONDITIONS DEVELOPING AT LAKE MICHIGAN BEACHES.  
   
SPOTTER INFORMATION STATEMENT
 
 
SPOTTER ACTIVATION WILL NOT BE NECESSARY THROUGH TONIGHT.  
 
GENERAL STORM MOTION OF THE DAY:  
 
MOVING TOWARD THE EAST-NORTHEAST AT 30 MPH.  
 

 
 
LMZ740>745-210845-  
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-  
341 AM CDT THU SEP 20 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
 
EARLY THIS MORNING THROUGH TONIGHT.  
 
WEATHER HAZARDS EXPECTED...  
 
HAZARDOUS CONDITIONS FOR SMALL CRAFT.  
ELEVATED THUNDERSTORM RISK.  
   
DAYS TWO THROUGH SEVEN
 
FRIDAY THROUGH WEDNESDAY.  
 
FRIDAY...  
HAZARDOUS CONDITIONS FOR SMALL CRAFT ARE LIKELY.  
LIMITED THUNDERSTORM RISK.  
SATURDAY...  
HAZARDOUS CONDITIONS FOR SMALL CRAFT ARE LIKELY.  
MONDAY AND TUESDAY...  
LIMITED THUNDERSTORM RISK.  
 

 
 
RATZER  
 
VISIT US AT HTTP://WEATHER.GOV/CHICAGO  
 
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:  
WWW.FACEBOOK.COM/NWSCHICAGO  
WWW.TWITTER.COM/NWSCHICAGO  
WWW.YOUTUBE.COM/NWSCHICAGO  
 
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