620
FZUS63 KMKX 021933
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
233 PM 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...

Modest to breezy south to southwest winds will become established
across Lake Michigan this afternoon into tonight as low pressure
deepens to 29.5 inches over northern Lake Superior. The low will
continue to deepen to near 29.4 inches during the day on Wednesday
as it progresses toward James Bay, Canada. A cold front will then
gradually cross Lake Michigan from north to south for Wednesday
afternoon, resulting in a gusty northwest wind shift across the
waters. Showers and storms will accompany the passing front on
Wednesday with a few storms producing gusty winds. A few
waterspouts are also possible, particularly 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.

LMZ261-362-364-366-563-565-567-868-030345-
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-
233 PM CDT Tue Sep 2 2025

SHEBOYGAN WI TO PENTWATER MI NORTH...

.TONIGHT...South winds 10 to 20 kt becoming southwest 15 to
25 kt. Chance of showers and thunderstorms overnight. Waves 3 to
5 ft.
.WEDNESDAY...Southwest winds 15 to 25 kt veering to northwest
10 to 20 kt. Chance of waterspouts. Showers likely with a chance
of thunderstorms in the morning, then chance of showers and
slight chance of thunderstorms in the afternoon. Waves 4 to 6 ft
occasionally to 8 ft subsiding to 3 to 5 ft.
.WEDNESDAY NIGHT...Northwest winds 10 to 20 kt increasing to
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. Chance of showers.
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.
.FRIDAY NIGHT...West winds to 30 kt diminishing to 15 to 25 kt.
Waves 4 to 6 ft occasionally to 8 ft.
.SATURDAY...Northwest winds 15 to 25 kt becoming west. Waves 3 to
5 ft.
.SUNDAY...Northwest winds 10 to 20 kt. Waves 1 to 3 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-030345-
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-
233 PM CDT Tue Sep 2 2025

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.TONIGHT...South winds 10 to 15 kt becoming southwest 10 to
20 kt. Chance of showers and slight chance of thunderstorms
overnight. Waves 2 to 4 ft.
.WEDNESDAY...Southwest winds 15 to 25 kt becoming west 10 to
20 kt. Chance of showers and thunderstorms in the morning, then
showers likely 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 10 to 20 kt increasing to
15 to 25 kt. Chance of showers. Waves 3 to 5 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
overnight. Showers likely overnight. 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.
.FRIDAY NIGHT...West winds 15 to 25 kt becoming northwest 10 to
20 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. Waves 4 to 6 ft occasionally
to 8 ft.
.SUNDAY...Northwest winds 10 to 20 kt becoming north 10 to 15 kt.
Waves 2 to 4 ft.

$$

LMZ761-030345-
MAFOR 0222/
MICHIGAN NORTH 11410 11430 12530 11536 11546 11630 11720. A
chance of waterspouts Wednesday. A chance of thunderstorms
overnight and Wednesday morning. Waves 1 to 3 feet building to 2
to 4 feet tonight. Waves 3 to 6 feet Wednesday.

MICHIGAN SOUTH 12410 13520 12530 11626. A chance of thunderstorms
Wednesday. Waves 1 to 3 feet tonight. Waves 2 to 4 feet building
to 3 to 5 feet Wednesday.

$$


Gehring

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

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