743  
FLUS43 KLOT 201819  
HWOLOT  
 
HAZARDOUS WEATHER OUTLOOK  
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL  
119 PM CDT THU JUL 20 2017  
 
ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-  
211830-  
WINNEBAGO-BOONE-MCHENRY-LAKE ILLINOIS-OGLE-LEE-DE KALB-KANE-  
DUPAGE-COOK-LA SALLE-KENDALL-GRUNDY-WILL-KANKAKEE-LIVINGSTON-  
IROQUOIS-FORD-LAKE INDIANA-PORTER-NEWTON-JASPER-BENTON-  
119 PM CDT THU JUL 20 2017 /219 PM EDT THU JUL 20 2017/  
 
THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS...  
NORTHEAST ILLINOIS AND NORTHWEST INDIANA.  
   
DAY ONE
 
THIS AFTERNOON AND TONIGHT.  
 
WEATHER HAZARDS EXPECTED:  
LIMITED THUNDERSTORM RISK...WITH AN ASSOCIATED:  
LIMITED HAIL RISK...UP TO QUARTER SIZE.  
ELEVATED THUNDERSTORM WIND DAMAGE RISK...UP TO 60 MPH.  
LIMITED FLOODING RISK.  
ELEVATED EXCESSIVE HEAT RISK.  
 
DISCUSSION:  
 
SCATTERED THUNDERSTORM DEVELOPMENT IS POSSIBLE SOUTH OF A  
ROCHELLE, IL TO RENSSELAER, IN LINE THROUGH THIS EVENING. THE MAIN  
THREAT FROM ALL STORMS WILL BE TORRENTIAL RAINFALL. HOWEVER, ONLY  
THE STRONGEST STORMS WILL BE CAPABLE OF PRODUCING LARGE HAIL AND  
DAMAGING WINDS.  
 
HEAT INDICES WILL BE AROUND OR JUST OVER 100 DEGREES THIS  
AFTERNOON.  
 
FLOODING WILL CONTINUE ALONG PORTIONS OF THE FOX AND DES PLAINES  
RIVERS.  
   
DAYS TWO THROUGH SEVEN
 
FRIDAY THROUGH WEDNESDAY.  
 
FRIDAY...  
SIGNIFICANT FLOODING RISK.  
ELEVATED SEVERE THUNDERSTORM RISK.  
ELEVATED EXCESSIVE HEAT RISK.  
SATURDAY...  
LIMITED FLOODING RISK.  
ELEVATED SEVERE THUNDERSTORM RISK.  
ELEVATED EXCESSIVE HEAT RISK.  
SUNDAY...  
LIMITED THUNDERSTORM RISK.  
WEDNESDAY...  
LIMITED THUNDERSTORM RISK.  
 
DISCUSSION:  
 
AN ACTIVE AND HUMID WEATHER PATTERN WILL CONTINUE THROUGH  
SATURDAY. THUNDERSTORMS ARE LIKELY AT TIMES FRIDAY AND MORE SO  
FRIDAY NIGHT, ESPECIALLY NORTH OF INTERSTATE 80. THE POTENTIAL FOR  
HEAVY RAIN IN THE REGION IS SIGNIFICANT WHICH COULD CAUSE  
WORSENED FLOODING. HOWEVER, THE EXACT LOCATION OF THE HEAVIEST  
RAINFALL IS UNCERTAIN. IN ADDITION THERE IS A SEVERE THUNDERSTORM  
THREAT, MAINLY NORTH OF INTERSTATE 80, ON FRIDAY AND FRIDAY NIGHT  
AS WELL. THUNDERSTORM CHANCES CONTINUE ON SATURDAY, SHIFTING  
MAINLY ALONG AND SOUTH OF INTERSTATE 80 BY SATURDAY NIGHT.  
 
HEAT INDEX READINGS WILL APPROACH 105 DEGREES BOTH FRIDAY AND  
SATURDAY, MAINLY ALONG AND SOUTH OF INTERSTATE 80.  
 
IN ADDITION, FLOODING WILL CONTINUE ALONG PORTIONS OF THE FOX AND  
DES PLAINES RIVERS AND MAY DEVELOP ALONG OTHER RIVERS OF FAR  
NORTHERN ILLINOIS.  
   
SPOTTER INFORMATION STATEMENT
 
 
SPOTTERS MAY BE NEEDED THROUGH THIS EVENING.  
 
GENERAL STORM MOTION OF THE DAY:  
 
MOVING TOWARD THE SOUTHEAST AT 35 TO 40 MPH.  
 

 
 

 
 
LMZ740>745-211830-  
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-  
119 PM CDT THU JUL 20 2017  
 
THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS NEARSHORE  
WATERS OF LAKE MICHIGAN AND THE INDIANA NEARSHORE WATERS OF LAKE  
MICHIGAN.  
   
DAY ONE
 
THIS AFTERNOON AND TONIGHT.  
 
LIMITED THUNDERSTORM RISK.  
   
DAYS TWO THROUGH SEVEN
 
FRIDAY THROUGH WEDNESDAY.  
 
FRIDAY...  
SIGNIFICANT THUNDERSTORM RISK.  
SATURDAY...  
LIMITED THUNDERSTORM RISK.  
SUNDAY...  
LIMITED THUNDERSTORM RISK.  
HAZARDOUS CONDITIONS FOR SMALL CRAFT ARE LIKELY.  
MONDAY...  
HAZARDOUS CONDITIONS FOR SMALL CRAFT ARE LIKELY.  
WEDNESDAY...  
LIMITED THUNDERSTORM RISK.  
 

 
 

 
 
LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-  
870-872-874-876-878-211830-  
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 FROM PENTWATER TO MANISTEE MI 5 NM OFFSHORE TO MID  
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-  
119 PM CDT THU JUL 20 2017  
 
THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE OPEN WATERS OF LAKE  
MICHIGAN.  
   
DAY ONE
 
THIS AFTERNOON AND TONIGHT.  
 
THERE IS A SLIGHT CHANCE OF THUNDERSTORMS OVER THE SOUTHERN END OF  
THE LAKE.  
   
DAYS TWO THROUGH SEVEN
 
FRIDAY THROUGH WEDNESDAY.  
 
PERIODS OF THUNDERSTORMS ARE EXPECTED THROUGH SATURDAY AND  
AGAIN POSSIBLE ON WEDNESDAY.  
 

 
 

 
 
JEE  
 
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