347
FZUS63 KMKX 020746
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
246 AM CDT Tue Sep 2 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...

30.1 inch high pressure remains focused over the western Great
Lakes early this morning, resulting in east-northeast winds over
the southern half of Lake Michigan and east-southeast winds
further north. Prevailing south to southwest winds will become
established across the waters by this afternoon as low pressure
begins to develop over central Ontario. The low will move into
Lake Superior tonight, deepening to near 29.6 inches in the
process. The low will continue to deepen to near 29.4 inches
during the day on Wednesday as it slowly progresses toward the
Ontario- Quebec border. Southwest winds will thus become gusty
across Lake Michigan tonight into Wednesday morning. Highest gusts
are anticipated over the northern third of the waters, where a
few gusts approaching gale force are possible Wednesday morning.
Said gusts aren`t expected to be persistent or widespread, making
Gale Warnings unlikely at this time. Trends will continue to be
monitored through today.

A cold front will cross Lake Michigan Wednesday afternoon & evening,
resulting a gusty northwest wind shift across the waters. Currently
anticipate that gusts will remain below gale thresholds, though
trends will continue to be monitored. Showers and storms will
accompany the approaching/passing front Wednesday morning and
afternoon. Widespread strong to severe storms aren`t expected,
though a few storms could produce gusty winds. A few waterspouts are
also possible, particularly Wednesday morning and afternoon across
the northern half of the open waters.

30.0 inch high pressure will settle into the northern Great
Plains early Thursday morning, migrating into the western Ohio
River Valley by Thursday evening. The feature`s progression will
result in a southwest wind shift across the waters during the day
Thursday. Winds will become gusty Thursday night as a second area
of 29.5 inch low pressure quickly develops in the northern Great
Plains. The low will move across Lake Michigan Friday morning,
with gusty northwest winds becoming established during the
afternoon hours. Wind gusts could thus approach gale thresholds
once more Thursday night through Friday afternoon. Showers and
isolated storms will accompany the passing low, particularly late
Thursday night into early Friday morning.

LMZ261-362-364-366-563-565-567-868-021530-
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-
246 AM CDT Tue Sep 2 2025

SHEBOYGAN WI TO PENTWATER MI NORTH...

.TODAY...Southwest winds 5 to 10 kt increasing to 10 to 15 kt.
Waves 1 to 2 ft.
.TONIGHT...South winds 10 to 20 kt becoming southwest 15 to
25 kt. Chance of showers and slight chance of thunderstorms
overnight. Waves 3 to 5 ft.
.WEDNESDAY...Southwest winds 15 to 25 kt veering to northwest.
Chance of waterspouts. Showers with a chance of thunderstorms.
Waves 4 to 6 ft occasionally to 8 ft.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 kt. Chance of
waterspouts. Chance of showers. Waves 4 to 6 ft occasionally to
8 ft.
.THURSDAY...West winds 15 to 25 kt. Waves 3 to 5 ft.
.THURSDAY NIGHT...Southwest winds 15 to 25 kt. Waves 3 to 5 ft
building to 4 to 7 ft occasionally to 9 ft.
.FRIDAY...West winds to 30 kt. Chance of showers. Waves 5 to 8 ft
occasionally to 10 ft.
.SATURDAY...Northwest winds 15 to 25 kt becoming west. Waves 3 to
5 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-021530-
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-
246 AM CDT Tue Sep 2 2025

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.TODAY...Southeast winds 5 to 10 kt becoming southwest. Waves
1 to 2 ft.
.TONIGHT...South winds 10 to 15 kt becoming southwest 10 to
20 kt. Waves 2 to 4 ft.
.WEDNESDAY...Southwest winds 10 to 20 kt becoming west. Chance of
showers in the morning, then showers with a chance of
thunderstorms in the afternoon. Waves 4 to 6 ft occasionally to
8 ft.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 kt. Chance of showers
in the evening. Waves 4 to 6 ft occasionally to 8 ft building to
5 to 8 ft occasionally to 10 ft.
.THURSDAY...Northwest winds 15 to 25 kt becoming west. Waves 4 to
7 ft occasionally to 9 ft subsiding to 4 to 6 ft occasionally to
8 ft.
.THURSDAY NIGHT...Southwest winds 10 to 20 kt increasing to
30 kt. Waves 4 to 6 ft occasionally to 8 ft building to 5 to 8 ft
occasionally to 10 ft.
.FRIDAY...West winds to 30 kt. Waves 7 to 10 ft occasionally to
13 ft.
.SATURDAY...West winds 10 to 20 kt. Waves 4 to 6 ft occasionally
to 8 ft.

$$

LMZ761-021530-
MAFOR 0210/
MICHIGAN NORTH 12500 12510 11410 11420 11520 11530. Waves 2 feet
or less today. Waves 1 to 3 feet building to 2 to 4 feet tonight.

MICHIGAN SOUTH 11300 11500 11600 11610 12410 12520. Waves 2 feet
or less today. Waves 1 to 3 feet tonight.

$$


Quigley

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

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