


Great Lakes Forecast
Issued by NWS
Issued by NWS
604 FZUS63 KMKX 241336 GLFLM OPEN LAKE FORECAST for Lake Michigan National Weather Service Milwaukee/Sullivan WI 836 AM CDT Sun Aug 24 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... Low pressure of 29.4 inches will remain over James Bay through Monday and thus brisk northwest winds will persist. Winds will slowly weaken Tuesday as high pressure around 30.3 inches builds into the Great Lakes region from the northwest. There is a potential for waterspouts across the lake today and tomorrow. From late this morning through Monday the best potential will be across the northern half of the lake. The chances for waterspouts will expand to the southern half of the lake as colder air aloft drifts southward. There will also be a potential for rain and a few thunderstorms during this time. As high pressure begins to build in Monday night into Tuesday, the waterspout potential will end. LMZ261-362-364-366-563-565-567-868-242115- 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- 836 AM CDT Sun Aug 24 2025 SHEBOYGAN WI TO PENTWATER MI NORTH... .REST OF TODAY...West winds 10 to 20 kt becoming northwest 15 to 25 kt. Chance of waterspouts. Chance of showers and slight chance of thunderstorms through mid morning, then showers likely with a chance of thunderstorms this afternoon. Waves 3 to 5 ft. .TONIGHT...Northwest winds to 30 kt diminishing to 10 to 20 kt. Chance of waterspouts. Chance of showers and slight chance of thunderstorms in the evening, then chance of showers overnight. Waves 4 to 6 ft occasionally to 8 ft. .MONDAY...Northwest winds 15 to 25 kt increasing to 30 kt. Waves 3 to 5 ft subsiding to 2 to 4 ft. .MONDAY NIGHT...Northwest winds 15 to 25 kt diminishing to 10 to 20 kt. Waves 2 to 4 ft. .TUESDAY...Northwest winds 10 to 20 kt. Waves 1 to 3 ft. .TUESDAY NIGHT...Northwest winds 10 to 20 kt becoming west 10 to 15 kt. Waves 1 to 2 ft. .WEDNESDAY...West winds 10 to 20 kt becoming southwest 15 to 25 kt. Waves 1 to 3 ft. .THURSDAY...Northwest winds 10 to 20 kt becoming north. Chance of sprinkles. Waves 1 to 3 ft. $$ LMZ080-669-671-673-675-777-779-870-872-874-876-878-242115- 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- 836 AM CDT Sun Aug 24 2025 SHEBOYGAN WI TO PENTWATER MI SOUTH... .REST OF TODAY...Northwest winds 10 to 20 kt increasing to 15 to 25 kt. Chance of waterspouts. Slight chance of showers and thunderstorms this afternoon. Waves 4 to 6 ft occasionally to 8 ft. .TONIGHT...Northwest winds 15 to 25 kt diminishing to 10 to 20 kt. Chance of waterspouts. Chance of showers and slight chance of thunderstorms in the evening, then chance of showers overnight. Waves 4 to 7 ft occasionally to 9 ft. .MONDAY...Northwest winds 10 to 20 kt increasing to 15 to 25 kt. Waves 4 to 7 ft occasionally to 9 ft. .MONDAY NIGHT...Northwest winds 10 to 20 kt. Waves 3 to 5 ft. .TUESDAY...Northwest winds 10 to 20 kt. Waves 3 to 5 ft. .TUESDAY NIGHT...Northwest winds 10 to 20 kt diminishing to 10 to 15 kt. Waves 2 to 4 ft subsiding to 1 to 3 ft. .WEDNESDAY...West winds 10 to 15 kt increasing to 10 to 20 kt. Waves 1 to 3 ft. .THURSDAY...West winds 10 to 20 kt becoming northwest. Chance of sprinkles. Waves 2 to 4 ft. $$ LMZ761-242115- MAFOR 2416/ MICHIGAN NORTH 11630 11736 13730 11720 12730. A chance of waterspouts this afternoon and tonight. A chance of thunderstorms this afternoon. Waves 2 to 4 feet this afternoon. Waves 3 to 5 feet tonight. Waves 3 to 5 feet subsiding to 2 to 4 feet Monday morning. MICHIGAN SOUTH 11630 14730 13720. A chance of waterspouts this afternoon and tonight. A chance of showers tonight. Waves 3 to 5 feet this afternoon. Waves 3 to 6 feet tonight and Monday morning. $$ Boxell Experimental modernized open lake forecast is available online at weather.gov/mkx/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes