FZUS63 KMKX 231900 GLFLM OPEN LAKE FORECAST for Lake Michigan National Weather Service Milwaukee/Sullivan WI 200 PM CDT Sun Aug 23 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... Scattered shower chances continue over the northern third of Lake Michigan today, with a few waterspouts possible. 29.7 inch low pressure is centered near the Ontario-Quebec border, resulting in breezy northwest winds across the open waters of Lake Michigan. The breezy winds will continue through tonight as the low lingers in the same general vicinity. Expecting most gusts to remain in the 25-30 knot range, though a few gusts approaching gale force are possible over the northern third of the lake. Given the brief & isolated nature of any such gusts, not anticipating the need for any gale headlines, but will be monitoring trends. 30.1 inch high pressure will steadily build into the Upper Mississippi Valley today, reaching the waters by Monday afternoon. The high's arrival will lead to decreasing winds, with conditions becoming light and variable by Monday evening. Light and variable winds will continue Monday night with high pressure lingering in the vicinity. The high will shift east into Ontario by Tuesday, resulting in a south-southwest wind shift across the waters. 29.7 inch low pressure will approach from the northern Great Plains Tuesday night into Wednesday, reinforcing the south-southwesterly wind pattern. The low will cross Lake Michigan during the second half of the day Wednesday, bringing a breezy northwest wind shift. Gales are not expected as this occurs. Showers and thunderstorms will accompany the approaching/passing surface low Tuesday night into Wednesday afternoon. It remains too early to tell if any of these storms could be severe, with trends being monitored through the beginning of this week. The next area of 30.1 inch high pressure will gradually build toward Lake Michigan from the northern Great Plains Wednesday night through Friday, bringing slowly decreasing winds. LMZ261-362-364-366-563-565-567-868-240315- 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- 200 PM CDT Sun Aug 23 2026 SHEBOYGAN WI TO PENTWATER MI NORTH... .TONIGHT...North winds to 30 kt becoming northwest. Waves 4 to 6 ft occasionally to 8 ft. .MONDAY...Northwest winds to 30 kt becoming north 15 to 25 kt. Waves 4 to 6 ft occasionally to 8 ft subsiding to 2 to 4 ft. .MONDAY NIGHT...North winds 10 to 20 kt diminishing to 5 to 10 kt. Waves 1 to 3 ft subsiding to 1 to 2 ft. .TUESDAY...Southwest winds 10 to 15 kt increasing to 15 to 25 kt in the afternoon. Waves 1 to 2 ft building to 2 to 4 ft. .TUESDAY NIGHT...South winds 15 to 25 kt. Chance of showers overnight. Waves 3 to 5 ft. .WEDNESDAY...South winds to 30 kt becoming southwest. Showers in the morning, then showers likely with a chance of thunderstorms in the afternoon. Waves 4 to 6 ft occasionally to 8 ft. .WEDNESDAY NIGHT...Southwest winds 15 to 25 kt becoming west 10 to 20 kt. Waves 4 to 6 ft occasionally to 8 ft subsiding to 2 to 4 ft. .THURSDAY...Northwest winds 10 to 20 kt increasing to 30 kt. Waves 1 to 3 ft. .FRIDAY...North winds 10 to 20 kt. Waves 1 to 3 ft. $$ LMZ080-669-671-673-675-777-779-870-872-874-876-878-240315- 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- 200 PM CDT Sun Aug 23 2026 SHEBOYGAN WI TO PENTWATER MI SOUTH... .TONIGHT...North winds 10 to 20 kt becoming northwest. Waves 4 to 6 ft occasionally to 8 ft subsiding to 2 to 4 ft. .MONDAY...Northwest winds 10 to 20 kt becoming north. Waves 2 to 4 ft. .MONDAY NIGHT...Northeast winds 10 to 20 kt becoming northwest 5 to 10 kt late in the evening, then becoming west after midnight becoming west 5 to 10 kt late. Waves 2 to 4 ft subsiding to 1 to 2 ft. .TUESDAY...Southwest winds 10 to 15 kt becoming south 10 to 20 kt. Waves 1 to 2 ft building to 2 to 4 ft. .TUESDAY NIGHT...South winds 10 to 20 kt increasing to 15 to 25 kt. Waves 3 to 5 ft. .WEDNESDAY...Southwest winds to 30 kt. Chance of showers in the morning, then chance of showers and thunderstorms in the afternoon. Waves 4 to 6 ft occasionally to 8 ft. .WEDNESDAY NIGHT...Southwest winds 15 to 25 kt becoming west 10 to 20 kt. Waves 4 to 6 ft occasionally to 8 ft subsiding to 2 to 4 ft. .THURSDAY...Northwest winds 10 to 20 kt becoming north. Waves 2 to 4 ft. .FRIDAY...North winds 10 to 20 kt. Waves 2 to 4 ft. $$ LMZ761-240315- MAFOR 2322/ MICHIGAN NORTH 12840 12740 13730 11830. Waves 3 to 6 feet tonight. Waves 3 to 5 feet subsiding to 1 to 3 feet Monday. MICHIGAN SOUTH 11830 12820 11710 13720 11820. Waves 3 to 5 feet subsiding to 2 to 4 feet tonight. Waves 2 to 4 feet Monday. $$ Quigley Experimental modernized open lake forecast is available online at weather.gov/mkx/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes