102
FZUS63 KMKX 220155
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
855 PM CDT Fri Aug 21 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...

Some lingering showers and storms over the lake possible this
evening as a weak low pressure system around 29.8 inches will
cross Lake Michigan from north to south tonight and bring a wind
shift to the northwest. Then look for gusty northerly winds to
develop along a cold front that will track from north to south
down Lake Michigan Saturday evening. A few thunderstorms are
possible along this front. Northerly winds will persist through
Sunday as low pressure around 29.6 inches tracks from Lower
Michigan to Ontario. Variable winds are expected for Monday and
Tuesday as high pressure of 30.1 inches crosses the Upper Great
Lakes.

LMZ261-362-364-366-563-565-567-868-220915-
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-
855 PM CDT Fri Aug 21 2026

SHEBOYGAN WI TO PENTWATER MI NORTH...

.REST OF TONIGHT...South winds 10 to 20 kt veering to north.
Chance of showers and slight chance of thunderstorms. Waves 3 to
5 ft.
.SATURDAY...North winds 10 to 20 kt becoming northwest to 30 kt.
Slight chance of showers and thunderstorms in the afternoon.
Waves 3 to 5 ft.
.SATURDAY NIGHT...North winds to 30 kt becoming northwest 15 to
25 kt. Waves 4 to 6 ft occasionally to 8 ft.
.SUNDAY...North winds to 30 kt. Waves 4 to 6 ft occasionally to
8 ft.
.SUNDAY NIGHT...North winds to 30 kt diminishing to 10 to 20 kt
overnight. Waves 3 to 5 ft subsiding to 2 to 4 ft.
.MONDAY...Northwest winds 10 to 20 kt. Waves 1 to 3 ft.
.MONDAY NIGHT...Southwest winds 10 to 20 kt diminishing to 5 to
10 kt. Waves 1 to 2 ft.
.TUESDAY...Southwest winds 10 to 20 kt increasing to 15 to 25 kt.
Waves 1 to 2 ft building to 2 to 4 ft.
.WEDNESDAY...Southwest winds 15 to 25 kt increasing to 30 kt.
Chance of showers. Waves 3 to 5 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-220915-
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-
855 PM CDT Fri Aug 21 2026

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.REST OF TONIGHT...South winds 10 to 20 kt veering to northwest.
Slight chance of showers and thunderstorms. Waves 2 to 4 ft.
.SATURDAY...Northwest winds 10 to 20 kt increasing to 15 to
25 kt. Waves 4 to 6 ft occasionally to 8 ft.
.SATURDAY NIGHT...North winds 15 to 25 kt. Waves 4 to 6 ft
occasionally to 8 ft.
.SUNDAY...North winds to 30 kt. Waves 5 to 8 ft occasionally to
10 ft.
.SUNDAY NIGHT...North winds 15 to 25 kt becoming northwest 10 to
15 kt overnight. Waves 4 to 7 ft occasionally to 9 ft subsiding
to 2 to 4 ft.
.MONDAY...North winds 10 to 15 kt. Waves 1 to 3 ft.
.MONDAY NIGHT...East winds 5 to 10 kt veering to south. Waves
1 to 2 ft.
.TUESDAY...South winds 10 to 20 kt increasing to 15 to 25 kt.
Waves 1 to 2 ft building to 2 to 4 ft.
.WEDNESDAY...Southwest winds 15 to 25 kt. Waves 3 to 5 ft.

$$

LMZ761-220915-
MAFOR 2204/
MICHIGAN NORTH 11610 11720 11820 11720 11730 11740 12840. A
chance of showers overnight. Waves 1 to 3 feet overnight. Waves 2
to 4 feet Saturday. Waves 3 to 6 feet Saturday evening.

MICHIGAN SOUTH 11510 12720 14730 11830. Waves 1 to 3 feet
overnight. Waves 3 to 6 feet Saturday. Waves 3 to 5 feet
subsiding to 2 to 4 feet Saturday evening.

$$


Kuroski

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

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