157
FZUS63 KMKX 220152
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
852 PM CDT Thu Aug 21 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 30.1 inches will linger into Friday before
weakening. Light winds are expected through tonight, shifting to
become southwesterly into Friday as high pressure weakens and low
pressure strengthens over northwestern Ontario. Winds become
breezy across the northern two thirds of the open waters Friday
afternoon ahead of a strong cold front, which will progress
northwest to southeast Friday night into Saturday morning. Expect
scattered showers and isolated thunderstorms along this front.
Winds shift to become west-northwesterly and brisk Saturday
through Monday as low pressure deepens to 29.5 inches in
northeastern Ontario. Then winds weaken and become northwesterly
into Tuesday.

LMZ261-362-364-366-563-565-567-868-220930-
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 PM CDT Thu Aug 21 2025

SHEBOYGAN WI TO PENTWATER MI NORTH...

.REST OF TONIGHT...Northwest winds 10 to 15 kt backing to
southwest. Waves 1 to 2 ft.
.FRIDAY...Southwest winds 10 to 15 kt increasing to 10 to 20 kt.
Waves 2 to 4 ft.
.FRIDAY NIGHT...Southwest winds 10 to 20 kt becoming west. Chance
of showers and thunderstorms in the evening, then chance of
showers overnight. Waves 2 to 4 ft.
.SATURDAY...West winds 10 to 20 kt increasing to 15 to 25 kt.
Chance of showers in the morning. Waves 2 to 4 ft.
.SATURDAY NIGHT...Northwest winds 10 to 20 kt becoming west.
Waves 3 to 5 ft.
.SUNDAY...West winds 15 to 25 kt. Chance of showers. Waves 3 to
5 ft.
.SUNDAY NIGHT...Northwest winds 15 to 25 kt. Chance of showers.
Waves 3 to 5 ft.
.MONDAY...Northwest winds 15 to 25 kt increasing to 30 kt. Chance
of showers. Waves 4 to 6 ft occasionally to 8 ft.
.TUESDAY...Northwest winds 10 to 20 kt. Waves 2 to 4 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-220930-
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 PM CDT Thu Aug 21 2025

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.REST OF TONIGHT...North winds 10 to 15 kt becoming northeast
after midnight, then becoming less than 10 kt late. Waves 1 to
3 ft.
.FRIDAY...Northwest winds 5 to 10 kt backing to southwest. Waves
1 to 2 ft.
.FRIDAY NIGHT...South winds 10 to 15 kt becoming west 10 to
20 kt. Waves 2 to 4 ft.
.SATURDAY...West winds 10 to 20 kt. Waves 2 to 4 ft.
.SATURDAY NIGHT...Northwest winds 10 to 20 kt. Waves 4 to 6 ft
occasionally to 8 ft.
.SUNDAY...Northwest winds 15 to 25 kt becoming west. Waves 4 to
6 ft occasionally to 8 ft.
.SUNDAY NIGHT...Northwest winds 15 to 25 kt. Waves 4 to 7 ft
occasionally to 9 ft.
.MONDAY...Northwest winds 15 to 25 kt. Waves 4 to 7 ft
occasionally to 9 ft.
.TUESDAY...Northwest winds 10 to 20 kt becoming north. Waves 3 to
5 ft.

$$

LMZ761-220930-
MAFOR 2204/
MICHIGAN NORTH 11400 11500 11510 14520 11520. A chance of showers
and thunderstorms Friday evening. Waves 1 foot or less overnight.
Waves 1 to 3 feet Friday and Friday evening.

MICHIGAN SOUTH 12100 11800 12600 11510 12410. Waves 2 feet or
less.

$$


MH

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

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