108
FZUS63 KMKX 221921
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
221 PM CDT Fri Aug 22 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 30.0 inches will weaken southeast of the
region tonight. South to southwest winds will linger into
tonight, ahead of a strong cold front. The front will move
southeast across the lake tonight into Saturday morning. Widely
scattered showers and a few thunderstorms are expected along this
front.

Winds shift to the west northwest and become brisk Saturday
through Monday, as low pressure strengthens to around 29.4 inches
over James Bay. There will be a potential for some waterspouts
across the northern half of the lake Sunday into Monday, as
temperatures drop and lake effect showers develop. Winds will
weaken and become northwest by Tuesday.

LMZ261-362-364-366-563-565-567-868-230330-
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-
221 PM CDT Fri Aug 22 2025

SHEBOYGAN WI TO PENTWATER MI NORTH...

.TONIGHT...Southwest winds 15 to 25 kt becoming west. Chance of
showers and thunderstorms this evening, then chance of showers
and slight chance of thunderstorms overnight. Waves 2 to 4 ft.
.SATURDAY...West winds 10 to 20 kt becoming northwest. Slight
chance of showers and thunderstorms in the morning, then slight
chance of showers in the afternoon. Waves 2 to 4 ft.
.SATURDAY NIGHT...Northwest winds 10 to 20 kt. Waves 2 to 4 ft.
.SUNDAY...West winds 15 to 25 kt. Slight chance of waterspouts.
Chance of showers. Waves 3 to 5 ft.
.SUNDAY NIGHT...Northwest winds 15 to 25 kt. Slight chance of
waterspouts. Chance of showers. Waves 3 to 5 ft.
.MONDAY...Northwest winds 15 to 25 kt increasing to 30 kt. Slight
chance of waterspouts. Chance of showers. Waves 3 to 5 ft.
.MONDAY NIGHT...North winds to 30 kt becoming northwest 10 to
20 kt. Waves 2 to 4 ft.
.TUESDAY...Northwest winds 10 to 20 kt. Waves 1 to 3 ft.
.WEDNESDAY...West winds 10 to 20 kt becoming southwest 15 to
25 kt. Waves 1 to 2 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-230330-
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-
221 PM CDT Fri Aug 22 2025

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.TONIGHT...South winds 10 to 20 kt becoming southwest. Slight
chance of showers and thunderstorms overnight. Waves 1 to 3 ft.
.SATURDAY...West winds 10 to 20 kt becoming northwest. Slight
chance of showers and thunderstorms in the morning. 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 10 to 20 kt increasing to 15 to 25 kt.
Waves 4 to 6 ft occasionally to 8 ft.
.SUNDAY NIGHT...Northwest winds 15 to 25 kt. Chance of showers in
the evening. 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.
.MONDAY NIGHT...Northwest winds 10 to 20 kt. Waves 4 to 6 ft
occasionally to 8 ft subsiding to 3 to 5 ft.
.TUESDAY...Northwest winds 10 to 20 kt. Waves 2 to 4 ft.
.WEDNESDAY...West winds 10 to 20 kt. Waves 1 to 3 ft.

$$

LMZ761-230330-
MAFOR 2222/
MICHIGAN NORTH 14530 14620. A chance of showers and thunderstorms
this evening. A chance of showers overnight. Waves 1 to 3 feet
building to 2 to 4 feet, then subsiding to 1 to 3 feet tonight.
Waves 1 to 3 feet Saturday.

MICHIGAN SOUTH 12420 12520 13620 11720. Waves 1 to 3 feet.

$$
Wood

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

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