


Great Lakes Forecast
Issued by NWS
Issued by NWS
792 FZUS63 KMKX 161350 GLFLM OPEN LAKE FORECAST for Lake Michigan National Weather Service Milwaukee/Sullivan WI 850 AM CDT Wed Jul 16 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... Southerly winds will increase this morning ahead of an approaching low pressure around 29.7 inches and accompanying front. Expect the low pressure over northern IA to move across southern WI this afternoon and cross the middle portion of Lake Michigan through the evening. Accompanying this system will be increased thunderstorm chances which may produce strong, gusty winds across Lake Michigan through the late afternoon and evening. Will first see northerly winds gradually build down across the northern half of the lake through the afternoon as the front shifts southeast ahead the low pressure, which will move across the Lake later this evening/tonight. Expect breezy northerly winds to migrate into the southern half of the lake overnight and persist into Thursday as high pressure around 30.2 inches builds into the Upper Midwest. Lighter, shifting winds are expected for Friday as the high pressure moves over the Upper Great Lakes. Increasing southerly flow then returns for the start of the weekend. LMZ261-362-364-366-563-565-567-868-162115- 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- 850 AM CDT Wed Jul 16 2025 SHEBOYGAN WI TO PENTWATER MI NORTH... .REST OF TODAY...West winds 10 to 15 kt veering to north 10 to 20 kt. Slight chance of showers and thunderstorms. Waves 1 to 3 ft. .TONIGHT...North winds 15 to 25 kt. Showers likely with a chance of thunderstorms. Waves 3 to 5 ft building to 4 to 7 ft occasionally to 9 ft. .THURSDAY...North winds 15 to 25 kt increasing to 30 kt. Waves 4 to 7 ft occasionally to 9 ft. .THURSDAY NIGHT...North winds 15 to 25 kt becoming northeast 10 to 15 kt overnight. Waves 4 to 6 ft occasionally to 8 ft subsiding to 2 to 4 ft. .FRIDAY...Southeast winds 5 to 10 kt veering to southwest 10 to 15 kt. Waves 1 to 2 ft. .FRIDAY NIGHT...South winds 5 to 10 kt. Waves 1 ft or less. .SATURDAY...South winds 10 to 15 kt. Chance of showers. Waves 1 ft or less. .SUNDAY...North winds 10 to 15 kt increasing to 10 to 20 kt. Waves 1 to 2 ft. $$ LMZ080-669-671-673-675-777-779-870-872-874-876-878-162115- 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- 850 AM CDT Wed Jul 16 2025 SHEBOYGAN WI TO PENTWATER MI SOUTH... .REST OF TODAY...South winds 5 to 10 kt increasing to 10 to 20 kt. Chance of thunderstorms and slight chance of showers this afternoon. Waves 1 to 2 ft. .TONIGHT...South winds 15 to 25 kt veering to northwest. Showers likely with a chance of thunderstorms in the evening, then chance of showers and thunderstorms overnight. Waves 2 to 4 ft building to 4 to 7 ft occasionally to 9 ft. .THURSDAY...Northwest winds 15 to 25 kt becoming north to 30 kt. Waves 6 to 9 ft occasionally to 12 ft. .THURSDAY NIGHT...North winds 15 to 25 kt becoming northeast 10 to 20 kt. Waves 5 to 8 ft occasionally to 10 ft subsiding to 4 to 6 ft occasionally to 8 ft. .FRIDAY...East winds 10 to 15 kt becoming northeast 5 to 10 kt. Waves 2 to 4 ft subsiding to 1 to 3 ft. .FRIDAY NIGHT...Northeast winds 5 to 10 kt veering to southeast. Waves 1 to 2 ft. .SATURDAY...South winds 10 to 15 kt. Chance of showers. Waves 1 to 2 ft. .SUNDAY...North winds 10 to 15 kt increasing to 10 to 20 kt. Waves 1 to 3 ft. $$ LMZ761-162115- MAFOR 1616/ MICHIGAN NORTH 11810 11820 11830 13836 12830. A chance of thunderstorms tonight. Waves 1 to 3 feet this afternoon. Waves 2 to 4 feet building to 3 to 6 feet tonight. Waves 3 to 6 feet Thursday morning. MICHIGAN SOUTH 12410 11426 11536 11630 12730 11830. A chance of thunderstorms this afternoon and tonight. Waves 2 feet or less this afternoon. Waves 2 to 4 feet building to 3 to 6 feet tonight. Waves 3 to 6 feet building to 4 to 7 feet Thursday morning. $$ Halbach Experimental modernized open lake forecast is available online at weather.gov/mkx/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes