Great Lakes Forecast
Issued by NWS
Issued by NWS
119 FZUS63 KMKX 161822 GLFLM OPEN LAKE FORECAST for Lake Michigan National Weather Service Milwaukee/Sullivan WI 122 PM CDT Sun Aug 16 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... A cold front is approaching the open waters of Lake Michigan this afternoon, resulting in breezy west-northwest winds. These conditions will continue into this evening as the front clears east of the waters. A scattered shower or thunderstorm is possible along the departing boundary, particularly over the southern third of the waters. Severe weather is not anticipated. A new area of 30.1 inch high pressure will build in from the northern Great Plains late tonight into Monday, bringing light and variable winds to the waters through the majority of Monday and Monday night. A slow-moving cold front will approach from the northern Great Plains Tuesday into Wednesday, bringing increasing southwest winds and chances for thunderstorms. Tuesday evening and night appears most favored for storm potential, with storm chances expected to move well south of the waters on Wednesday. 30.0 inch high pressure will move through the western Great Lakes Wednesday through Thursday, with light and variable winds prevailing across the waters. The next thunderstorm chances arrive Friday afternoon and evening, when the next cold front is expected to move across Lake Michigan. LMZ261-362-364-366-563-565-567-868-170315- 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- 122 PM CDT Sun Aug 16 2026 SHEBOYGAN WI TO PENTWATER MI NORTH... .TONIGHT...North winds 15 to 25 kt diminishing to 10 to 15 kt. Waves 2 to 4 ft subsiding to 1 to 3 ft. .MONDAY...Northwest winds 10 to 15 kt backing to southwest 10 to 20 kt. Waves 1 to 2 ft. .MONDAY NIGHT...Southwest winds 10 to 20 kt. Waves 2 to 4 ft. .TUESDAY...West winds 15 to 25 kt. Chance of showers in the afternoon. Waves 2 to 4 ft. .TUESDAY NIGHT...North winds 10 to 20 kt. Chance of showers in the evening. Waves 2 to 4 ft. .WEDNESDAY...Northwest winds 10 to 15 kt increasing to 10 to 20 kt. Waves 1 to 3 ft. .WEDNESDAY NIGHT...East winds 10 to 20 kt becoming northeast 5 to 10 kt. Waves 1 to 2 ft. .THURSDAY...West winds 5 to 10 kt becoming southwest 10 to 20 kt. Waves 1 ft or less. .FRIDAY...Southwest winds 15 to 25 kt increasing to 30 kt. Waves 2 to 4 ft. $$ LMZ080-669-671-673-675-777-779-870-872-874-876-878-170315- Lake Michigan from Michigan City IN to St. Joseph MI 5 NM offshore to Mid Lake- Lake Michigan from Sheboygan to Port Washington WI 5 NM offshore to Mid Lake- Lake Michigan from Port Washington to North Point Light WI 5 NM offshore to Mid Lake- Lake Michigan from North Point Light to Wind Point WI 5 NM offshore to Mid Lake- Lake Michigan from Wind Point WI to Winthrop Harbor IL 5 NM offshore to Mid Lake- Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5 NM offshore to Mid Lake- Lake Michigan from Wilmette Harbor IL to Michigan City IN 5 NM offshore to Mid Lake- Lake Michigan from Whitehall to Pentwater MI 5 NM offshore to Mid Lake- Lake Michigan from Grand Haven to Whitehall MI 5 NM offshore to Mid Lake- Lake Michigan from Holland to Grand Haven MI 5 NM offshore to Mid Lake- Lake Michigan from South Haven to Holland MI 5 NM offshore to Mid Lake- Lake Michigan from St. Joseph to South Haven MI 5 NM offshore to Mid Lake- 122 PM CDT Sun Aug 16 2026 SHEBOYGAN WI TO PENTWATER MI SOUTH... .TONIGHT...Northwest winds 10 to 20 kt becoming northeast. Waves 2 to 4 ft. .MONDAY...North winds 10 to 15 kt. Waves 2 to 4 ft subsiding to 1 to 2 ft. .MONDAY NIGHT...Southwest winds 10 to 15 kt increasing to 10 to 20 kt. Waves 2 to 4 ft. .TUESDAY...Southwest winds 10 to 20 kt. Waves 2 to 4 ft. .TUESDAY NIGHT...West winds 10 to 20 kt veering to north. Chance of showers. Waves 2 to 4 ft. .WEDNESDAY...Northeast winds 10 to 15 kt becoming north 10 to 20 kt. Chance of showers in the morning. Waves 2 to 4 ft. .WEDNESDAY NIGHT...Northeast winds 10 to 15 kt backing to northwest 5 to 10 kt. Waves 1 to 2 ft. .THURSDAY...Southwest winds 5 to 10 kt becoming south 10 to 15 kt. Waves 1 to 2 ft. .FRIDAY...South winds 10 to 20 kt increasing to 15 to 25 kt. Waves 1 to 3 ft. $$ LMZ761-170315- MAFOR 1622/ MICHIGAN NORTH 12830 11820 11810 11710 11700 11610 11510. Waves 1 to 3 feet building to 2 to 4 feet, then subsiding to 1 to 3 feet tonight. Waves 2 feet or less Monday. MICHIGAN SOUTH 11720 12820 11120 14810. Waves 1 to 3 feet. $$ Quigley Experimental modernized open lake forecast is available online at weather.gov/mkx/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes