915
FZUS63 KMKX 010737
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
237 AM CDT Mon Sep 1 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...

30.3 inch high pressure is centered over Lake Huron this morning,
resulting in generally light northeasterly winds over the
southern third of Lake Michigan, light/variable winds over the
central third, and light/southeasterly winds over the northern
third. This general pattern will persist into Tuesday morning as
the broad area of high pressure slowly migrates into Ontario.
South to southwest winds will become established late Tuesday
afternoon through Tuesday night as low pressure of at least 29.6
inches develops across Lake Superior. Said area of low pressure
will slowly move east toward the Ontario-Quebec border Wednesday,
dragging a strong cold front across Lake Michigan in the process.
Gusty northwest winds will become established along and behind the
passing front Wednesday evening through Thursday morning.
Widespread gale-force gusts are not anticipated at this time,
though forecast trends will be closely monitored through the
beginning of this week. Winds are forecast to turn west-
southwesterly Thursday afternoon and night as second area of low
pressure develops across the western Great Lakes. Central pressure
of the low, in addition to its precise location, remain a source
of uncertainty at this time, with forecast trends being monitored
through this week. Additional gusts in the 20-25 knot range will
be possible during this time frame. The second area of low
pressure will cross over or just to the north of Lake Michigan
during the day on Friday, resulting in a northwest wind shift
Friday night into Saturday.

Showers and thunderstorms are likely along the advancing cold front
Wednesday and Wednesday evening. Widespread severe thunderstorms
aren`t anticipated, though a few storms could produce gusty winds.
Forecast trends will also be monitored for waterspout potential
during the day on Wednesday, particularly across the northern half
of the open waters. Additional showers and isolated thunderstorms
will be possible ahead of the second low on Friday. Whether or not
gusty winds or waterspouts will accompany this activity remains
uncertain at this time.

LMZ261-362-364-366-563-565-567-868-011515-
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-
237 AM CDT Mon Sep 1 2025

SHEBOYGAN WI TO PENTWATER MI NORTH...

.TODAY...South winds less than 10 kt becoming west. Waves nearly
calm.
.TONIGHT...Northeast winds 5 to 10 kt backing to southwest. Waves
nearly calm.
.TUESDAY...Southwest winds 5 to 10 kt increasing to 10 to 20 kt.
Waves 1 to 2 ft.
.TUESDAY NIGHT...South winds 10 to 20 kt becoming southwest.
Waves 2 to 4 ft.
.WEDNESDAY...Southwest winds 15 to 25 kt becoming west. Showers
likely in the morning, then showers with a chance of
thunderstorms in the afternoon. Waves 3 to 5 ft building to 4 to
6 ft occasionally to 8 ft.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 kt. Chance of
showers. Waves 4 to 6 ft occasionally to 8 ft.
.THURSDAY...Northwest winds 15 to 25 kt becoming west. Waves 3 to
5 ft.
.FRIDAY...Southwest winds 15 to 25 kt becoming west. Chance of
showers. Waves 4 to 6 ft occasionally to 8 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-011515-
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-
237 AM CDT Mon Sep 1 2025

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.TODAY...Southeast winds 5 to 10 kt backing to north. Waves 1 ft
or less.
.TONIGHT...North winds 5 to 10 kt veering to east. Waves 1 to
2 ft.
.TUESDAY...Southeast winds 5 to 10 kt veering to west. Waves 1 ft
or less.
.TUESDAY NIGHT...South winds 10 to 15 kt becoming southwest 10 to
20 kt. Waves 1 to 3 ft.
.WEDNESDAY...Southwest winds 10 to 20 kt increasing to 15 to
25 kt. Chance of showers. Waves 3 to 5 ft building to 4 to 6 ft
occasionally to 8 ft.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 kt. Showers likely
with a chance of thunderstorms. Waves 4 to 6 ft occasionally to
8 ft building to 4 to 7 ft occasionally to 9 ft.
.THURSDAY...Northwest winds 15 to 25 kt becoming west. Waves 4 to
7 ft occasionally to 9 ft.
.FRIDAY...Southwest winds 15 to 25 kt becoming west. Chance of
showers. Waves 4 to 7 ft occasionally to 9 ft.

$$

LMZ761-011515-
MAFOR 0110/
MICHIGAN NORTH 13400 11500 11700 11200 11300 11400. Waves 1 foot
or less.

MICHIGAN SOUTH 13300 12800 12100 11200. Waves 1 foot or less.

$$


Quigley

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

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