872
FZUS63 KMKX 040158
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
858 PM CDT Wed Sep 3 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...

Low pressure of 29.4 inches over southern Ontario will meander
north and then northwest into Thursday while deepening to 29.2
inches. The low will remain nearly stationary Friday, before
lifting northeast Friday night into Saturday. Breezy west to
northwest winds tonight will become southerly by Thursday night.
Winds then become westerly by Friday morning as a secondary low
of 29.3 inches moves through northern Lake Michigan. This low will
bring a tighter pressure gradient and a period of gales Thursday
night into Friday morning. Increased confidence on increasing
winds has lead to a Gale Watch for late Thursday night into Friday
afternoon. Winds will then gradually ease later Friday into the
weekend as high pressure of 30.3 inches moves in from the
northwest.

LMZ261-362-364-366-563-565-567-868-040915-
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-
858 PM CDT Wed Sep 3 2025

SHEBOYGAN WI TO PENTWATER MI NORTH...

...GALE WATCH IN EFFECT FROM LATE THURSDAY NIGHT THROUGH FRIDAY
AFTERNOON...

.REST OF TONIGHT...Northwest winds 15 to 25 kt becoming west.
Slight chance of waterspouts. Waves 4 to 7 ft occasionally to
9 ft subsiding to 4 to 6 ft occasionally to 8 ft.
.THURSDAY...West winds 15 to 25 kt becoming southwest. Slight
chance of waterspouts in the morning. Waves 3 to 5 ft.
.THURSDAY NIGHT...Southwest winds 15 to 25 kt increasing to 30 kt
after midnight, then becoming south gales to 40 kt late. Showers
overnight. Waves 3 to 5 ft building to 10 to 14 ft occasionally
to 18 ft.
.FRIDAY...West gales to 40 kt diminishing to 30 kt in the
afternoon. Showers in the morning. Waves 10 to 14 ft occasionally
to 18 ft subsiding to 7 to 10 ft occasionally to 13 ft.
.FRIDAY NIGHT...West winds to 30 kt diminishing to 15 to 25 kt.
Waves 4 to 7 ft occasionally to 9 ft.
.SATURDAY...West winds 15 to 25 kt. Chance of showers. Waves 3 to
5 ft.
.SATURDAY NIGHT...Northwest winds 10 to 20 kt diminishing to
10 to 15 kt. Waves 2 to 4 ft.
.SUNDAY...Northwest winds 10 to 20 kt. Waves 1 to 3 ft.
.MONDAY...Southwest winds 10 to 15 kt increasing to 10 to 20 kt.
Waves 1 to 2 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-040915-
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-
858 PM CDT Wed Sep 3 2025

SHEBOYGAN WI TO PENTWATER MI SOUTH...

...GALE WATCH IN EFFECT FROM LATE THURSDAY NIGHT THROUGH FRIDAY
AFTERNOON...

.REST OF TONIGHT...Northwest winds 15 to 25 kt diminishing to
10 to 20 kt. Slight chance of showers through early evening.
Waves 5 to 8 ft occasionally to 10 ft subsiding to 4 to 6 ft
occasionally to 8 ft.
.THURSDAY...Northwest winds 10 to 20 kt becoming west. Slight
chance of waterspouts in the morning. Waves 4 to 6 ft
occasionally to 8 ft subsiding to 2 to 4 ft.
.THURSDAY NIGHT...Southwest winds 10 to 20 kt increasing to gales
to 40 kt. Chance of showers overnight. Waves 2 to 4 ft building
to 10 to 14 ft occasionally to 18 ft.
.FRIDAY...West gales to 40 kt diminishing to 30 kt in the
afternoon. Waves 10 to 14 ft occasionally to 18 ft subsiding to
8 to 11 ft occasionally to 14 ft.
.FRIDAY NIGHT...West winds 15 to 25 kt. Waves 5 to 8 ft
occasionally to 10 ft subsiding to 4 to 7 ft occasionally to
9 ft.
.SATURDAY...West winds 10 to 20 kt increasing to 15 to 25 kt.
Waves 4 to 6 ft occasionally to 8 ft.
.SATURDAY NIGHT...Northwest winds 10 to 20 kt. Waves 3 to 5 ft.
.SUNDAY...Northwest winds 10 to 20 kt. Waves 3 to 5 ft.
.MONDAY...South winds 5 to 10 kt increasing to 10 to 15 kt. Waves
1 to 2 ft.

$$

LMZ761-040915-
MAFOR 0404/
MICHIGAN NORTH 12730 11630 12620 11630 12530. Waves 3 to 6 feet
overnight. Waves 3 to 5 feet subsiding to 2 to 4 feet Thursday.
Waves 2 to 4 feet Thursday evening.

MICHIGAN SOUTH 11730 13720 12620 12520. Waves 4 to 7 feet
subsiding to 3 to 6 feet overnight. Waves 3 to 5 feet subsiding
to 1 to 3 feet Thursday. Waves 1 to 3 feet building to 2 to 4
feet Thursday evening.

$$


Patterson

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

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