FZUS63 KMKX 190818 GLFLM OPEN LAKE FORECAST for Lake Michigan National Weather Service Milwaukee/Sullivan WI 318 AM CDT Tue May 19 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 Dense Fog Advisory is in effect through this morning for the north half of the lake as relatively mild and humid air flows over the cold lake waters. Otherwise modest to breezy southerly winds continue from now into early Tuesday afternoon with scattered thunderstorms possible over the southern two-thirds of the lake this morning. The gusty winds will be followed by the passage of a cold front late this afternoon as low pressure of 29.6 inches lifts from northern Lake Superior to central Quebec. Winds will shift to northwesterly with the cold frontal passage and remain a bit breezy. High pressure around 30.4 inches will then move into the northern Great Lakes for Wednesday afternoon into Thursday. Light to modest north to northeast winds can be expected. LMZ261-362-364-366-563-565-567-868-191530- 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- 318 AM CDT Tue May 19 2026 SHEBOYGAN WI TO PENTWATER MI NORTH... ...DENSE FOG ADVISORY IN EFFECT UNTIL NOON CDT TODAY... .TODAY...South winds to 30 kt veering to west. Widespread dense fog this morning, then patchy fog this afternoon. Chance of showers and slight chance of thunderstorms this morning, then chance of showers this afternoon. Waves 5 to 8 ft occasionally to 10 ft subsiding to 4 to 6 ft occasionally to 8 ft. .TONIGHT...Northwest winds 15 to 25 kt becoming north 10 to 20 kt. Waves 4 to 6 ft occasionally to 8 ft subsiding to 2 to 4 ft. .WEDNESDAY...North winds 10 to 20 kt becoming northeast 15 to 25 kt. Waves 2 to 4 ft. .WEDNESDAY NIGHT...Northeast winds 10 to 20 kt diminishing to 10 to 15 kt. Waves 1 to 3 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. .SATURDAY...Northeast winds to 30 kt diminishing to 15 to 25 kt. Waves 3 to 5 ft. $$ LMZ080-669-671-673-675-777-779-870-872-874-876-878-191530- Lake Michigan from Michigan City IN to St. Joseph MI 5 NM offshore to Mid Lake- Lake Michigan from Sheboygan to Port Washington WI 5 NM offshore to Mid Lake- Lake Michigan from Port Washington to North Point Light WI 5 NM offshore to Mid Lake- Lake Michigan from North Point Light to Wind Point WI 5 NM offshore to Mid Lake- Lake Michigan from Wind Point WI to Winthrop Harbor IL 5 NM offshore to Mid Lake- Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5 NM offshore to Mid Lake- Lake Michigan from Wilmette Harbor IL to Michigan City IN 5 NM offshore to Mid Lake- Lake Michigan from Whitehall to Pentwater MI 5 NM offshore to Mid Lake- Lake Michigan from Grand Haven to Whitehall MI 5 NM offshore to Mid Lake- Lake Michigan from Holland to Grand Haven MI 5 NM offshore to Mid Lake- Lake Michigan from South Haven to Holland MI 5 NM offshore to Mid Lake- Lake Michigan from St. Joseph to South Haven MI 5 NM offshore to Mid Lake- 318 AM CDT Tue May 19 2026 SHEBOYGAN WI TO PENTWATER MI SOUTH... .TODAY...South winds to 30 kt becoming west 15 to 25 kt. Patchy fog this morning. Chance of showers and slight chance of thunderstorms. Waves 5 to 8 ft occasionally to 10 ft subsiding to 4 to 6 ft occasionally to 8 ft. .TONIGHT...Northwest winds 10 to 20 kt becoming north. Waves 3 to 5 ft. .WEDNESDAY...North winds 10 to 20 kt increasing to 15 to 25 kt. Waves 4 to 6 ft occasionally to 8 ft. .WEDNESDAY NIGHT...Northeast winds 15 to 25 kt diminishing to 10 to 20 kt. Waves 4 to 6 ft occasionally to 8 ft. .THURSDAY...Northeast winds 10 to 20 kt. Waves 2 to 4 ft. .THURSDAY NIGHT...Northeast winds 10 to 20 kt becoming east. Waves 3 to 5 ft. .FRIDAY...East winds 10 to 20 kt becoming northeast. Chance of showers. Waves 3 to 5 ft. .SATURDAY...Northeast winds 10 to 20 kt becoming north 10 to 15 kt. Waves 2 to 4 ft. $$ LMZ761-191530- MAFOR 1910/ MICHIGAN NORTH 12444 11540 11640 11730 12720 11820. A chance of showers today. Waves 5 to 8 feet subsiding to 3 to 6 feet today. Waves 3 to 5 feet subsiding to 1 to 3 feet tonight. MICHIGAN SOUTH 11440 12530 11630 11730 12720 11820. A chance of showers today. Waves 5 to 8 feet subsiding to 3 to 6 feet today. Waves 3 to 5 feet subsiding to 2 to 4 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