615
FZUS63 KMKX 301945
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
245 PM CDT Sat Aug 30 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 over the Great Lakes
region through Monday, keeping winds light and variable across
Lake Michigan. Tuesday, low pressure around 29.8 inches crossing
southern Ontario will bring increasing south-southwesterly winds
into Wednesday morning. A cold front associated with this low
pressure system will bring a broken line of thunderstorms to the
lake, with some producing strong wind gusts, Wednesday into
Wednesday evening. Behind this cold front, expect west-northwesterly
winds with gusts around 30 kt. Isolated gales are possible, and
trends will be monitored with future updates to assess gale
potential. Winds continue through Thursday. Northern portions of
Lake Michigan will continue to see showers into Thursday as well,
and waterspouts may be added in future forecast updates if pattern
remains favorable.

LMZ261-362-364-366-563-565-567-868-310315-
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-
245 PM CDT Sat Aug 30 2025

SHEBOYGAN WI TO PENTWATER MI NORTH...

.TONIGHT...Southwest winds 5 to 10 kt diminishing to less than
10 kt. Waves 1 ft or less.
.SUNDAY...South winds less than 10 kt becoming southwest. Waves
1 ft or less.
.SUNDAY NIGHT...Southwest winds 5 to 10 kt becoming south. Waves
1 ft or less.
.MONDAY...Southwest winds 5 to 10 kt increasing to 10 to 15 kt.
Waves nearly calm.
.MONDAY NIGHT...South winds 5 to 10 kt. Waves nearly calm.
.TUESDAY...Southwest winds 10 to 15 kt increasing to 10 to 20 kt.
Waves 1 to 2 ft.
.TUESDAY NIGHT...South winds 10 to 20 kt becoming southwest.
Waves 1 to 3 ft.
.WEDNESDAY...Southwest winds 10 to 20 kt becoming northwest to
30 kt. Showers likely. Waves 2 to 4 ft building to 4 to 6 ft
occasionally to 8 ft.
.THURSDAY...Northwest winds to 30 kt becoming west. Waves 4 to
6 ft occasionally to 8 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-310315-
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-
245 PM CDT Sat Aug 30 2025

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.TONIGHT...North winds 5 to 10 kt becoming east. Waves 1 ft or
less.
.SUNDAY...East winds 5 to 10 kt becoming north. Waves 1 ft or
less.
.SUNDAY NIGHT...Northeast winds 5 to 10 kt becoming east. Waves
1 ft or less.
.MONDAY...East winds 5 to 10 kt becoming northeast. Waves 1 ft or
less.
.MONDAY NIGHT...Northeast winds 5 to 10 kt becoming east. Waves
1 ft or less.
.TUESDAY...Southeast winds 5 to 10 kt becoming south. Waves 1 ft
or less.
.TUESDAY NIGHT...South winds 5 to 10 kt increasing to 10 to
15 kt. Waves 1 to 3 ft.
.WEDNESDAY...Southwest winds 10 to 20 kt becoming west 15 to
25 kt. Chance of showers. Waves 3 to 5 ft building to 4 to 6 ft
occasionally to 8 ft.
.THURSDAY...Northwest winds 15 to 25 kt becoming west to 30 kt.
Waves 6 to 9 ft occasionally to 12 ft.

$$

LMZ761-310315-
MAFOR 3022/
MICHIGAN NORTH 11510 13500 12400 12500. Waves 1 foot or less.

MICHIGAN SOUTH 11800 12100 14200 11100. Waves 1 foot 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