358
FZUS63 KMKX 311352
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
852 AM CDT Sun Aug 31 2025

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...

High pressure around 30.2 inches will linger over the region into
Tuesday, which will continue to bring light winds over Lake
Michigan. Southwest winds will become established Tuesday night,
as low pressure around 29.7 inches develops near Lake Superior.
The low will slowly move to the Ontario and Quebec border
Wednesday and Wednesday night, dragging a strong cold front across
the open waters of Lake Michigan in the process. The frontal
passage will result in a gusty northwest wind shift across the
waters Wednesday evening through the day on Thursday.

The current forecast maintains gusts just below gale force
thresholds during this period, though increases to or above gale
force may occur in later forecasts. Showers and thunderstorms
will accompany the passing cold front Wednesday into Thursday. It
remains too early to pinpoint any possibility for waterspouts with
this activity, though forecast trends will be closely monitored.
Breezy west winds will continue through Friday.

LMZ261-362-364-366-563-565-567-868-312115-
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-
852 AM CDT Sun Aug 31 2025

SHEBOYGAN WI TO PENTWATER MI NORTH...

.REST OF TODAY...Southwest winds 5 to 10 kt increasing to 10 to
15 kt. Waves 1 ft or less.
.TONIGHT...Southwest winds 5 to 10 kt becoming south. Waves 1 ft
or less.
.MONDAY...Southwest winds 5 to 10 kt increasing to 10 to 15 kt.
Waves nearly calm.
.MONDAY NIGHT...Southeast winds 5 to 10 kt becoming south. Waves
nearly calm.
.TUESDAY...Southwest winds 10 to 15 kt increasing to 10 to 20 kt.
Waves 1 to 2 ft.
.TUESDAY NIGHT...Southwest winds 10 to 20 kt. Waves 1 to 3 ft.
.WEDNESDAY...Southwest winds 10 to 20 kt becoming west 15 to
25 kt. Showers with a chance of thunderstorms. Waves 2 to 4 ft
building to 3 to 5 ft.
.THURSDAY...Northwest winds 15 to 25 kt becoming west to 30 kt.
Waves 4 to 6 ft occasionally to 8 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-312115-
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-
852 AM CDT Sun Aug 31 2025

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.REST OF TODAY...East winds less than 10 kt backing to north.
Waves nearly calm.
.TONIGHT...North winds 5 to 10 kt veering to east. Waves 1 ft or
less.
.MONDAY...Southeast winds 5 to 10 kt backing to north. Waves 1 ft
or less.
.MONDAY NIGHT...Northeast winds 5 to 10 kt becoming east. Waves
1 ft or less.
.TUESDAY...Southeast winds 5 to 10 kt becoming southwest. Waves
1 ft or less.
.TUESDAY NIGHT...South winds 10 to 15 kt becoming southwest.
Waves 1 to 2 ft.
.WEDNESDAY...Southwest winds 10 to 20 kt becoming west 15 to
25 kt. Chance of showers and thunderstorms. Waves 2 to 4 ft
building to 3 to 5 ft.
.THURSDAY...Northwest winds 15 to 25 kt increasing to 30 kt.
Waves 6 to 9 ft occasionally to 12 ft.

$$

LMZ761-312115-
MAFOR 3116/
MICHIGAN NORTH 12510 11500 13400 11500 11400. Waves 1 foot or
less.

MICHIGAN SOUTH 11200 12800 12100 11200 12300. Waves 1 foot or
less.

$$
Wood

Experimental modernized open lake forecast is available online at
weather.gov/mkx/glftable

Graphical marine forecasts are available online at:
weather.gov/greatlakes