


Great Lakes Forecast
Issued by NWS
Issued by NWS
050 FZUS63 KMKX 210744 GLFLM OPEN LAKE FORECAST for Lake Michigan National Weather Service Milwaukee/Sullivan WI 244 AM CDT Thu Aug 21 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 of 30.1 inches will slowly sink southeastward from northern WI to southern WI through today, lingering into Friday but gradually weakening and shifting southeast. Expect fog to develop across the northern third of the lake as light and variable winds prevail under high pressure. Patchy dense fog is possible. Light and more variable winds are expected across the lake into the day today as high pressure settles into the region and decreases winds across the entirety of the lake. Winds turn southerly to southwesterly Friday afternoon ahead of a strong cold front, which will pass across the lake on Saturday. Expect scattered showers and thunderstorms along this front. Gusty west to northwest winds are expected from late Saturday through Monday behind this cold front as low pressure of 29.5 inches occludes over northern Ontario. LMZ261-362-364-366-563-565-567-868-211515- 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- 244 AM CDT Thu Aug 21 2025 SHEBOYGAN WI TO PENTWATER MI NORTH... .TODAY...Northeast winds 5 to 10 kt becoming northwest 10 to 15 kt. Patchy dense fog this morning. Waves 1 to 3 ft. .TONIGHT...Northwest winds 10 to 15 kt backing to southwest. Waves 1 to 3 ft subsiding to 1 to 2 ft. .FRIDAY...Southwest winds 10 to 15 kt increasing to 10 to 20 kt. Waves 1 to 3 ft. .FRIDAY NIGHT...Southwest winds 10 to 20 kt. Chance of showers. Waves 2 to 4 ft. .SATURDAY...West winds 10 to 20 kt. Waves 2 to 4 ft. .SATURDAY NIGHT...Northwest winds 10 to 20 kt. Waves 2 to 4 ft. .SUNDAY...West winds 10 to 20 kt increasing to 15 to 25 kt. Chance of showers. Waves 2 to 4 ft. .MONDAY...Northwest winds 15 to 25 kt. Chance of showers. Waves 3 to 5 ft. $$ LMZ080-669-671-673-675-777-779-870-872-874-876-878-211515- Lake Michigan from Michigan City IN to St. Joseph MI 5 NM offshore to Mid Lake- Lake Michigan from Sheboygan to Port Washington WI 5 NM offshore to Mid Lake- Lake Michigan from Port Washington to North Point Light WI 5 NM offshore to Mid Lake- Lake Michigan from North Point Light to Wind Point WI 5 NM offshore to Mid Lake- Lake Michigan from Wind Point WI to Winthrop Harbor IL 5 NM offshore to Mid Lake- Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5 NM offshore to Mid Lake- Lake Michigan from Wilmette Harbor IL to Michigan City IN 5 NM offshore to Mid Lake- Lake Michigan from Whitehall to Pentwater MI 5 NM offshore to Mid Lake- Lake Michigan from Grand Haven to Whitehall MI 5 NM offshore to Mid Lake- Lake Michigan from Holland to Grand Haven MI 5 NM offshore to Mid Lake- Lake Michigan from South Haven to Holland MI 5 NM offshore to Mid Lake- Lake Michigan from St. Joseph to South Haven MI 5 NM offshore to Mid Lake- 244 AM CDT Thu Aug 21 2025 SHEBOYGAN WI TO PENTWATER MI SOUTH... .TODAY...Northeast winds 10 to 15 kt becoming north 10 to 20 kt. Waves 2 to 4 ft subsiding to 1 to 3 ft. .TONIGHT...North winds 10 to 20 kt becoming northeast 10 to 15 kt after midnight, then diminishing to 5 to 10 kt late. Waves 2 to 4 ft. .FRIDAY...Southwest winds less than 10 kt becoming west late in the morning, then becoming west 5 to 10 kt early in the afternoon becoming south late. Waves 1 to 2 ft. .FRIDAY NIGHT...South winds 10 to 15 kt becoming southwest. Waves 1 to 3 ft. .SATURDAY...West winds 10 to 20 kt. Waves 2 to 4 ft. .SATURDAY NIGHT...Northwest winds 10 to 20 kt. Waves 4 to 6 ft occasionally to 8 ft. .SUNDAY...Northwest winds 10 to 20 kt becoming west 15 to 25 kt. Waves 3 to 5 ft. .MONDAY...Northwest winds 10 to 20 kt increasing to 15 to 25 kt. Waves 4 to 6 ft occasionally to 8 ft. $$ LMZ761-211515- MAFOR 2110/ MICHIGAN NORTH 12100 12810 11710 11700 11400 11500. Waves 2 feet or less. MICHIGAN SOUTH 11110 11210 11110 11810 12820 11110 11100. Waves 2 to 4 feet subsiding to 1 to 3 feet today. Waves 1 to 3 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