821
FZUS63 KMKX 131943
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
243 PM CDT Wed Aug 13 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 of 30.2 inches will remain dominant over Ontario
Canada Tonight through Thursday, resulting in light and variable
winds over the lake. High pressure drifts further east across
Canada later this week as a surface pressure trough deepens over
the Rockies and High Plains. This will allow 10 to 20 knot
southerly winds to develop Friday. Chances for showers and
thunderstorms return Saturday through the first half of next week
as a cold front slowly sags southward across the lake and stalls
somewhere nearby.

LMZ261-362-364-366-563-565-567-868-140330-
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-
243 PM CDT Wed Aug 13 2025

SHEBOYGAN WI TO PENTWATER MI NORTH...

.TONIGHT...Northeast winds 10 to 15 kt diminishing to 5 to 10 kt.
Areas of smoke this evening. Waves 1 to 2 ft.
.THURSDAY...Northeast winds 5 to 10 kt. Waves 1 to 2 ft.
.THURSDAY NIGHT...East winds 5 to 10 kt veering to south 10 to
15 kt. Waves 1 to 2 ft.
.FRIDAY...South winds 10 to 20 kt. Waves 1 to 3 ft.
.FRIDAY NIGHT...South winds 10 to 20 kt becoming southwest. Waves
1 to 3 ft.
.SATURDAY...Southwest winds 10 to 20 kt. Chance of showers. Waves
1 to 3 ft.
.SATURDAY NIGHT...West winds 10 to 20 kt veering to north 10 to
15 kt. Chance of showers and thunderstorms. Waves 1 to 3 ft.
.SUNDAY...Northeast winds 10 to 20 kt. Waves 2 to 4 ft.
.MONDAY...Southeast winds 10 to 20 kt. Chance of showers and
thunderstorms. Waves 2 to 4 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-140330-
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-
243 PM CDT Wed Aug 13 2025

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.TONIGHT...North winds 10 to 15 kt becoming northeast 5 to 10 kt.
Areas of smoke overnight. Waves 1 to 3 ft.
.THURSDAY...Northeast winds 5 to 10 kt becoming north. Areas of
smoke in the morning. Waves 1 to 2 ft.
.THURSDAY NIGHT...Northeast winds 5 to 10 kt veering to
southeast. Waves 1 to 2 ft.
.FRIDAY...South winds 10 to 15 kt increasing to 10 to 20 kt.
Waves 1 to 3 ft.
.FRIDAY NIGHT...South winds 10 to 20 kt diminishing to 10 to
15 kt. Waves 1 to 3 ft.
.SATURDAY...Southwest winds 10 to 20 kt becoming south. Chance of
showers in the morning. Waves 1 to 3 ft.
.SATURDAY NIGHT...South winds 10 to 15 kt becoming west. Chance
of showers and thunderstorms. Waves 1 to 3 ft.
.SUNDAY...North winds 10 to 15 kt increasing to 10 to 20 kt.
Waves 3 to 5 ft.
.MONDAY...Southeast winds 10 to 20 kt. Chance of showers. Waves
3 to 5 ft.

$$

LMZ761-140330-
MAFOR 1322/
MICHIGAN NORTH 11810 12110 13100 11200 11100. Waves 2 feet or
less.

MICHIGAN SOUTH 11810 11800 15100. Waves 1 to 3 feet tonight.
Waves 2 feet or less Thursday.

$$


Sheppard

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

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