226  
FZUS63 KMKX 200745  
GLFLM  
 
OPEN LAKE FORECAST FOR LAKE MICHIGAN  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
245 AM CDT WED AUG 20 2025  
 
FOR WATERS BEYOND FIVE NAUTICAL MILES OF SHORE ON LAKE MICHIGAN.  
 
WAVES ARE PROVIDED AS A RANGE OF SIGNIFICANT WAVE HEIGHTS, WHICH  
IS THE AVERAGE OF THE HIGHEST 1/3 OF THE WAVE, ALONG WITH THE  
AVERAGE HEIGHT OF THE HIGHEST 10% OF THE WAVES WHICH WILL  
OCCASIONALLY BE ENCOUNTERED.  
   
SYNOPSIS
 
 
 
HIGH PRESSURE AROUND 30.1 INCHES WILL REMAIN OVER THE GREAT LAKES  
THROUGH FRIDAY. A BREEZY PERIOD OF NORTHERLY WINDS WILL PERSIST  
THROUGH TODAY AS THE HIGH MOVES IN BEHIND A RETREATING LOW  
PRESSURE AROUND 29.8 INCHES. LIGHT TO MODERATE NORTH WINDS ARE  
THEN EXPECTED TONIGHT INTO EARLY FRIDAY, BEFORE WINDS TURN  
SOUTHERLY FRIDAY MORNING HEAD OF AN APPROACHING COLD FRONT.  
 
LMZ261-362-364-366-563-565-567-868-201515-  
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 PENTWATER TO MANISTEE MI 5 NM OFFSHORE TO MID  
LAKE-  
245 AM CDT WED AUG 20 2025  
 
SHEBOYGAN WI TO PENTWATER MI NORTH...  
   
TODAY
 
NORTHEAST WINDS 10 TO 15 KT BECOMING NORTH 10 TO 20 KT.  
WAVES 1 TO 3 FT BUILDING TO 2 TO 4 FT.    
TONIGHT
 
NORTH WINDS 15 TO 25 KT BECOMING NORTHEAST 10 TO  
15 KT. WAVES 3 TO 5 FT SUBSIDING TO 2 TO 4 FT.    
THURSDAY
 
NORTHEAST WINDS 5 TO 10 KT BECOMING NORTH 10 TO 20 KT  
IN THE AFTERNOON. WAVES 1 TO 3 FT.    
THURSDAY NIGHT
 
NORTHEAST WINDS 10 TO 15 KT VEERING TO SOUTH.  
WAVES 1 TO 2 FT.    
FRIDAY
 
SOUTHWEST WINDS 10 TO 20 KT. WAVES 1 TO 2 FT.    
FRIDAY NIGHT
 
SOUTHWEST WINDS 10 TO 20 KT BECOMING WEST. CHANCE  
OF SHOWERS. WAVES 1 TO 3 FT.    
SATURDAY
 
WEST WINDS 10 TO 20 KT INCREASING TO 15 TO 25 KT.  
WAVES 2 TO 4 FT.    
SUNDAY
 
WEST WINDS 15 TO 25 KT. CHANCE OF SHOWERS. WAVES 3 TO  
5 FT.  
 

 
 
LMZ080-669-671-673-675-777-779-870-872-874-876-878-201515-  
LAKE MICHIGAN FROM MICHIGAN CITY IN TO ST. JOSEPH MI 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 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-  
245 AM CDT WED AUG 20 2025  
 
SHEBOYGAN WI TO PENTWATER MI SOUTH...  
   
TODAY
 
NORTHEAST WINDS 10 TO 20 KT BECOMING NORTH. CHANCE OF  
SPRINKLES THIS MORNING. WAVES 2 TO 4 FT.    
TONIGHT
 
NORTH WINDS 15 TO 25 KT BECOMING EAST 10 TO 20 KT.  
WAVES 4 TO 6 FT OCCASIONALLY TO 8 FT.    
THURSDAY
 
NORTHEAST WINDS 10 TO 15 KT BECOMING NORTH 10 TO  
20 KT. WAVES 3 TO 5 FT SUBSIDING TO 1 TO 3 FT.    
THURSDAY NIGHT
 
NORTH WINDS 10 TO 20 KT BECOMING EAST 5 TO  
10 KT OVERNIGHT. WAVES 1 TO 3 FT.    
FRIDAY
 
SOUTH WINDS 5 TO 10 KT BECOMING SOUTHWEST. WAVES 1 TO  
2 FT.    
FRIDAY NIGHT
 
SOUTHWEST WINDS 10 TO 15 KT BECOMING WEST 10 TO  
20 KT. WAVES 1 TO 3 FT.    
SATURDAY
 
WEST WINDS 10 TO 20 KT INCREASING TO 15 TO 25 KT.  
WAVES 2 TO 4 FT.    
SUNDAY
 
WEST WINDS 15 TO 25 KT BECOMING NORTHWEST TO 30 KT.  
WAVES 4 TO 6 FT OCCASIONALLY TO 8 FT.  
 

 
 
LMZ761-201515-  
MAFOR 2010/  
MICHIGAN NORTH 13110 11820 11830 11820 11120 11110. A CHANCE OF  
SHOWERS EARLY THIS MORNING. WAVES 2 FEET OR LESS BUILDING TO 2 TO  
4 FEET TODAY. WAVES 2 TO 4 FEET SUBSIDING TO 1 TO 3 FEET TONIGHT.  
 
MICHIGAN SOUTH 13120 11820 12830 11120 11210. WAVES 2 TO 4 FEET  
TODAY. WAVES 3 TO 5 FEET TONIGHT.  
 

 
 
KUROSKI  
 
EXPERIMENTAL MODERNIZED OPEN LAKE FORECAST IS AVAILABLE ONLINE AT  
WEATHER.GOV/MKX/GLFTABLE  
 
GRAPHICAL MARINE FORECASTS ARE AVAILABLE ONLINE AT:  
WEATHER.GOV/GREATLAKES  
 
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