086
FZUS63 KMKX 131630
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
1130 AM CDT Thu Aug 13 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 stalled frontal boundary just to the south of Lake Michigan will
remain in place until midday today, before retreating south
toward the Ohio River Valley. Periodic rain, storms and areas of
fog will be possible across the southern half of the lake until
this front moves south. Light and variable winds are expected
across the Lake today into tonight.

High pressure around 30.3 inches is expected to build down from
Ontario into the eastern Great Lakes tonight into Friday.
Northeast to east winds will increase across the lake becoming
breezy as the high pressure builds in and a low pressure system
develops across the Central Plains. As the low pressure around
29.9 inches moves northeast toward the Great Lakes Region, the
high pressure will be slowly moving northeast toward the New
England States. Winds will turn to southeasterly and remain breezy
Saturday ahead of the approaching low. This low is expected to
track across the Lake late Saturday into Sunday. Rain and
thunderstorms will be possible across the Lake Saturday into
Saturday night. As the low exits to the northeast Sunday, high
pressure around 30.2 inches is expected to move in from the
northern plains for early next week.

LMZ261-362-364-563-132100-
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 Rock Island Passage to Sturgeon Bay WI-
1130 AM CDT Thu Aug 13 2026

STURGEON BAY WI TO POINT BETSIE MI NORTH...

.REST OF TODAY...West winds 5 to 10 kt becoming southwest 10 to
15 kt. Waves 1 ft or less.
.TONIGHT...North winds 5 to 10 kt becoming northeast. Waves 1 to
2 ft.
.FRIDAY...Northeast winds 10 to 15 kt increasing to 10 to 20 kt.
Waves 1 to 2 ft.
.FRIDAY NIGHT...Northeast winds 10 to 20 kt becoming east 10 to
15 kt. Waves 1 to 2 ft.
.SATURDAY...Southeast winds 10 to 20 kt. Chance of showers. Waves
1 to 3 ft.
.SATURDAY NIGHT...Southeast winds 10 to 20 kt veering to
southwest. Chance of showers. Waves 2 to 4 ft.
.SUNDAY...Northwest winds 10 to 20 kt increasing to 15 to 25 kt.
Chance of showers. Waves 1 to 3 ft.
.MONDAY...Northwest winds 10 to 15 kt backing to southwest 10 to
20 kt. Waves 1 to 2 ft.

$$

LMZ366-565-567-669-868-870-132100-
Lake Michigan from Point Betsie to Manistee MI 5 NM offshore to
Mid Lake-
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 Sheboygan to Port Washington WI 5 NM offshore
to Mid Lake-
Lake Michigan from Pentwater to Manistee MI 5 NM offshore to Mid
Lake-
Lake Michigan from Whitehall to Pentwater MI 5 NM offshore to Mid
Lake-
1130 AM CDT Thu Aug 13 2026

STURGEON BAY WI TO POINT BETSIE MI SOUTH TO PORT WASHINGTON WI TO
WHITEHALL MI...

.REST OF TODAY...South winds less than 10 kt backing to east.
Patchy fog late this morning. Waves nearly calm.
.TONIGHT...Northeast winds 5 to 10 kt increasing to 10 to 15 kt.
Waves 1 to 2 ft.
.FRIDAY...Northeast winds 10 to 15 kt increasing to 15 to 25 kt.
Waves 2 to 4 ft.
.FRIDAY NIGHT...Northeast winds 10 to 20 kt becoming east. Waves
3 to 5 ft.
.SATURDAY...Southeast winds to 30 kt. Chance of showers in the
morning, then showers likely in the afternoon. Waves 4 to 6 ft
occasionally to 8 ft.
.SATURDAY NIGHT...South winds 10 to 20 kt becoming southwest.
Showers likely. Waves 3 to 5 ft subsiding to 2 to 4 ft.
.SUNDAY...Northwest winds 10 to 20 kt becoming north. Waves 2 to
4 ft.
.MONDAY...North winds 10 to 20 kt. Waves 1 to 3 ft.

$$

LMZ080-671-673-675-777-779-872-874-876-878-132100-
Lake Michigan from Michigan City IN to St. Joseph MI 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 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-
1130 AM CDT Thu Aug 13 2026

PORT WASHINGTON WI TO WHITEHALL MI SOUTH...

.REST OF TODAY...East winds less than 10 kt increasing to 5 to
10 kt early this afternoon, then becoming northeast late. Chance
of rain this afternoon. Waves nearly calm.
.TONIGHT...Northeast winds 10 to 15 kt becoming east. Chance of
rain and slight chance of thunderstorms in the evening, then
chance of showers and slight chance of thunderstorms overnight.
Waves 1 to 2 ft.
.FRIDAY...East winds 10 to 15 kt becoming northeast 10 to 20 kt.
Waves 1 to 3 ft.
.FRIDAY NIGHT...Northeast winds 10 to 20 kt becoming east. Chance
of showers overnight. Waves 3 to 5 ft.
.SATURDAY...Southeast winds 15 to 25 kt. Showers in the morning,
then showers likely with a chance of thunderstorms in the
afternoon. Waves 4 to 6 ft occasionally to 8 ft.
.SATURDAY NIGHT...South winds 10 to 20 kt becoming southwest.
Showers likely. Waves 2 to 4 ft.
.SUNDAY...West winds 10 to 20 kt becoming northwest. Waves 2 to
4 ft.
.MONDAY...North winds 10 to 20 kt. Waves 2 to 4 ft.

$$

LMZ761-132100-
MAFOR 1316/
MICHIGAN NORTH 11610 11510 11110 12100 13110. Waves 2 feet or
less.

MICHIGAN SOUTH 11200 11100 13110 13210. A chance of rain this
afternoon. A chance of rain this evening, then a chance of
showers overnight. Waves 2 feet or less this afternoon and
tonight. Waves 1 to 3 feet Friday morning.

$$


Halbach

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

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