734
FZUS63 KMKX 191349
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
849 AM CDT Fri Sep 19 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...

East to northeast winds gradually build today, reaching 15 to 20
kt speeds over northern portions of the lake as high pressure of
30.3 inches drifts southeastward across Ontario Canada. High
pressure deepens to 30.4 inches tonight, working with weak surface
low pressure over the northern Great Plains to veer winds east to
southeast, with the fastest speeds tonight (around 25 kts) over
the southern half of the lake. Southeast winds gradually subside
throughout Saturday, remaining a bit breezy over the northern tip
of the lake. Slower winds will veer due south into Sunday.

Intermittent rounds of showers and thunderstorms are expected
tonight through Monday night.

LMZ261-362-364-366-563-565-567-868-192115-
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-
849 AM CDT Fri Sep 19 2025

SHEBOYGAN WI TO PENTWATER MI NORTH...

.REST OF TODAY...East winds 10 to 20 kt becoming northeast. Waves
2 to 4 ft.
.TONIGHT...Northeast winds 10 to 20 kt becoming southeast 15 to
25 kt. Slight chance of showers and thunderstorms in the evening,
then chance of showers and slight chance of thunderstorms
overnight. Waves 4 to 6 ft occasionally to 8 ft.
.SATURDAY...Southeast winds 15 to 25 kt. Chance of showers. Waves
4 to 6 ft occasionally to 8 ft subsiding to 3 to 5 ft.
.SATURDAY NIGHT...Southeast winds 15 to 25 kt diminishing to
10 to 20 kt. Showers likely with a chance of thunderstorms. Waves
3 to 5 ft.
.SUNDAY...South winds 10 to 20 kt. Showers likely with a chance
of thunderstorms in the morning, then showers likely in the
afternoon. Waves 2 to 4 ft.
.SUNDAY NIGHT...South winds 10 to 15 kt becoming southwest 5 to
10 kt. Chance of showers. Waves 1 to 3 ft.
.MONDAY...Southwest winds 10 to 15 kt. Chance of showers. Waves
1 to 2 ft.
.TUESDAY...Northeast winds 10 to 15 kt increasing to 10 to 20 kt.
Waves 1 to 2 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-192115-
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-
849 AM CDT Fri Sep 19 2025

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.REST OF TODAY...East winds 5 to 10 kt becoming northeast 10 to
15 kt. Waves 1 to 3 ft.
.TONIGHT...Northeast winds 10 to 20 kt becoming east to 25 kt
late in the evening, then becoming southeast after midnight.
Slight chance of showers and thunderstorms in the evening, then
chance of showers and slight chance of thunderstorms overnight.
Waves 1 to 3 ft building to 4 to 7 ft occasionally to 9 ft.
.SATURDAY...Southeast winds 10 to 20 kt. Chance of showers. Waves
4 to 7 ft occasionally to 9 ft subsiding to 3 to 5 ft.
.SATURDAY NIGHT...Southeast winds 10 to 15 kt increasing to 10 to
20 kt. Showers likely with a chance of thunderstorms in the
evening, then showers likely overnight. Waves 2 to 4 ft.
.SUNDAY...South winds 10 to 20 kt. Showers likely with a chance
of thunderstorms. Waves 2 to 4 ft.
.SUNDAY NIGHT...Southwest winds 10 to 15 kt. Chance of showers.
Waves 1 to 3 ft.
.MONDAY...Southwest winds 10 to 15 kt. Chance of showers. Waves
1 to 3 ft.
.TUESDAY...Northeast winds 5 to 10 kt increasing to 10 to 20 kt.
Chance of showers. Waves 1 to 2 ft.

$$

LMZ761-192115-
MAFOR 1916/
MICHIGAN NORTH 11110 12120 12230 13330. A chance of showers
overnight and Saturday morning. Waves 1 to 3 feet this afternoon.
Waves 2 to 4 feet building to 3 to 5 feet tonight. Waves 3 to 6
feet Saturday morning.

MICHIGAN SOUTH 11210 12110 12240 11330 12320. A chance of showers
overnight and Saturday morning. Waves 2 feet or less this
afternoon. Waves 1 to 3 feet building to 3 to 6 feet tonight.
Waves 3 to 6 feet Saturday morning.

$$


Sheppard

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

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