FZUS63 KMKX 150736 GLFLM OPEN LAKE FORECAST for Lake Michigan National Weather Service Milwaukee/Sullivan WI 236 AM CDT Thu Oct 15 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 gradually become easterly tonight as high pressure around 30.3 inches slides through the region. The stronger winds are expected across the southern half of the lake during this time. Two areas of low pressure are progged to merge over the Great Lakes region into a single low pressure tonight and deepen to around 29.5 inches as it shifts into the eastern Great Lakes through Friday. Expect a northwesterly wind shift to ramp up and increase to gales and nearing storm force at times on the backside of the departing low pressure while a strong high pressure around 30.7 inches builds to the west. A Gale Warning is now in effect for all of the open waters of Lake Michigan Friday morning into Friday night. Widespread rain is expected this afternoon into tonight, with a few thunderstorms possible over the southern open waters. Lake effect showers & thundershowers may linger into Friday along the back side of departing low pressure. A few waterspouts are possible in the Friday showers/thundershowers, particularly over the southern half of Lake Michigan. As the high sinks toward the Ohio River Valley on Saturday, strong low pressure around 29.1 inches will develop in northern Manitoba. The tight pressure gradient may bring southwest gales to Lake Michigan on Sunday. LMZ261-362-364-366-563-565-567-868-151530- 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- 236 AM CDT Thu Oct 15 2026 SHEBOYGAN WI TO PENTWATER MI NORTH... ...GALE WARNING IN EFFECT FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT... .TODAY...Southeast winds 10 to 15 kt increasing to 10 to 20 kt. Showers this afternoon. Waves 3 to 5 ft. .TONIGHT...East winds 10 to 20 kt diminishing to 10 to 15 kt late in the evening, then becoming northeast 10 to 20 kt after midnight becoming north to 30 kt late. Showers in the evening, then chance of showers overnight. Waves 3 to 5 ft building to 4 to 7 ft occasionally to 9 ft. .FRIDAY...North winds to 30 kt increasing to gales to 45 kt. Chance of showers. Waves 6 to 9 ft occasionally to 12 ft building to 12 to 16 ft occasionally to 21 ft. .FRIDAY NIGHT...North gales to 40 kt diminishing to 30 kt overnight. Waves 12 to 16 ft occasionally to 21 ft subsiding to 8 to 12 ft occasionally to 16 ft. .SATURDAY...West winds 15 to 25 kt becoming southwest to 30 kt. Waves 4 to 6 ft occasionally to 8 ft. .SATURDAY NIGHT...Southwest winds to 30 kt increasing to gales to 35 kt. Waves 5 to 8 ft occasionally to 10 ft building to 7 to 10 ft occasionally to 13 ft. .SUNDAY...Southwest gales to 40 kt. Waves 8 to 12 ft occasionally to 16 ft. .MONDAY...Southwest winds 15 to 25 kt diminishing to 10 to 20 kt. Waves 4 to 7 ft occasionally to 9 ft subsiding to 3 to 5 ft. $$ LMZ080-669-671-673-675-777-779-870-872-874-876-878-151530- 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- 236 AM CDT Thu Oct 15 2026 SHEBOYGAN WI TO PENTWATER MI SOUTH... ...GALE WARNING IN EFFECT FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT... .TODAY...East winds 10 to 20 kt becoming southeast 15 to 25 kt. Showers this afternoon. Waves 4 to 7 ft occasionally to 9 ft. .TONIGHT...Southeast winds 10 to 20 kt increasing to 15 to 25 kt late in the evening, then veering to northwest to 30 kt overnight. Showers in the evening, then slight chance of showers overnight. Waves 4 to 6 ft occasionally to 8 ft building to 7 to 10 ft occasionally to 13 ft. .FRIDAY...Northwest winds to 30 kt increasing to gales to 35 kt late in the morning, then becoming north gales to 40 kt early in the afternoon increasing to gales to 45 kt late. Chance of showers in the morning, then showers in the afternoon. Waves 8 to 11 ft occasionally to 14 ft building to 14 to 18 ft occasionally to 23 ft. .FRIDAY NIGHT...North gales to 45 kt diminishing to 30 kt overnight. Chance of rain showers in the evening. Waves 15 to 20 ft occasionally to 26 ft subsiding to 12 to 16 ft occasionally to 21 ft. .SATURDAY...North winds 10 to 20 kt backing to southwest 15 to 25 kt. Waves 7 to 10 ft occasionally to 13 ft subsiding to 4 to 6 ft occasionally to 8 ft. .SATURDAY NIGHT...Southwest winds 15 to 25 kt increasing to 30 kt. Waves 6 to 9 ft occasionally to 12 ft. .SUNDAY...Southwest winds to 30 kt increasing to gales to 40 kt. Waves 8 to 11 ft occasionally to 14 ft building to 8 to 12 ft occasionally to 16 ft. .MONDAY...Southwest winds 10 to 20 kt. Waves 4 to 6 ft occasionally to 8 ft subsiding to 3 to 5 ft. $$ LMZ761-151530- MAFOR 1510/ MICHIGAN NORTH 12310 11320 11326 11226 11216 11126 11846. Waves 1 to 3 feet building to 2 to 4 feet today. Waves 2 to 4 feet building to 3 to 5 feet tonight. MICHIGAN SOUTH 11220 12320 13336 12740. Waves 3 to 6 feet today. Waves 3 to 6 feet building to 6 to 9 feet tonight. $$ Quigley Experimental modernized open lake forecast is available online at weather.gov/mkx/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes