FZUS63 KMKX 200759 GLFLM OPEN LAKE FORECAST for Lake Michigan National Weather Service Milwaukee/Sullivan WI 259 AM CDT Wed May 20 2026 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... Winds will come around from northwesterly to northeasterly through the first half of the day as high pressure around 30.4 inches builds into the Upper Great Lakes region today and then lingers into Thursday. Still looking at gusty northeast winds through midweek, especially over the southern half of the lake and building waves along the western lakeshore. High pressure continues to build to around 30.5 inches as it lifts northeastward across Ontario and Quebec Friday through the weekend with easterly winds persisting across Lake Michigan. Expecting winds to increase during this timeframe as well with a broad low pressure trough around 29.8 inches setting up over the Plains. 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- 259 AM CDT Wed May 20 2026 SHEBOYGAN WI TO PENTWATER MI NORTH... .TODAY...North winds 10 to 20 kt becoming northeast 15 to 25 kt. Waves 2 to 4 ft. .TONIGHT...Northeast winds 10 to 20 kt diminishing to 10 to 15 kt. Waves 2 to 4 ft. .THURSDAY...Northeast winds 10 to 15 kt increasing to 10 to 20 kt. Waves 1 to 3 ft. .THURSDAY NIGHT...Northeast winds 10 to 20 kt becoming east 10 to 15 kt. Waves 1 to 3 ft. .FRIDAY...East winds 10 to 20 kt becoming northeast 15 to 25 kt. Waves 1 to 3 ft building to 3 to 5 ft. .FRIDAY NIGHT...East winds 15 to 25 kt increasing to 30 kt. Chance of showers. Waves 4 to 6 ft occasionally to 8 ft. .SATURDAY...East winds to 30 kt becoming northeast. Chance of showers. Waves 4 to 7 ft occasionally to 9 ft. .SUNDAY...Southwest winds 10 to 15 kt. Waves 1 to 2 ft. $$ LMZ080-669-671-673-675-777-779-870-872-874-876-878-201515- Lake Michigan from Michigan City IN to St. Joseph MI 5 NM offshore to Mid Lake- Lake Michigan from Sheboygan to Port Washington WI 5 NM offshore to Mid Lake- Lake Michigan from Port Washington to North Point Light WI 5 NM offshore to Mid Lake- Lake Michigan from North Point Light to Wind Point WI 5 NM offshore to Mid Lake- Lake Michigan from Wind Point WI to Winthrop Harbor IL 5 NM offshore to Mid Lake- Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5 NM offshore to Mid Lake- Lake Michigan from Wilmette Harbor IL to Michigan City IN 5 NM offshore to Mid Lake- Lake Michigan from Whitehall to Pentwater MI 5 NM offshore to Mid Lake- Lake Michigan from Grand Haven to Whitehall MI 5 NM offshore to Mid Lake- Lake Michigan from Holland to Grand Haven MI 5 NM offshore to Mid Lake- Lake Michigan from South Haven to Holland MI 5 NM offshore to Mid Lake- Lake Michigan from St. Joseph to South Haven MI 5 NM offshore to Mid Lake- 259 AM CDT Wed May 20 2026 SHEBOYGAN WI TO PENTWATER MI SOUTH... .TODAY...North winds 10 to 20 kt increasing to 15 to 25 kt. Waves 3 to 5 ft building to 4 to 6 ft occasionally to 8 ft. .TONIGHT...North winds 15 to 25 kt becoming northeast 10 to 20 kt. Waves 4 to 6 ft occasionally to 8 ft. .THURSDAY...East winds 10 to 20 kt becoming north. Waves 3 to 5 ft subsiding to 2 to 4 ft. .THURSDAY NIGHT...Northeast winds 10 to 20 kt becoming east. Waves 3 to 5 ft. .FRIDAY...East winds 10 to 20 kt becoming northeast 15 to 25 kt. Chance of showers in the afternoon. Waves 3 to 5 ft. .FRIDAY NIGHT...East winds 15 to 25 kt. Showers likely. Waves 4 to 6 ft occasionally to 8 ft. .SATURDAY...East winds 10 to 20 kt becoming north 10 to 15 kt. Waves 4 to 6 ft occasionally to 8 ft subsiding to 2 to 4 ft. .SUNDAY...South winds 5 to 10 kt. Waves 1 ft or less. $$ LMZ761-201515- MAFOR 2010/ MICHIGAN NORTH 13820 11130 12120 12110. Waves 1 to 3 feet. MICHIGAN SOUTH 12820 13830 11130 12120. Waves 2 to 4 feet building to 3 to 6 feet today. Waves 3 to 6 feet tonight. $$ CMiller Experimental modernized open lake forecast is available online at weather.gov/mkx/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes