330
FZUS63 KMKX 121337
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
837 AM CDT Sat Jul 12 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...

A broad area of low pressure around 29.8 inches continues to
gradually lift northeastward across WI and Lake Michigan this
morning. It looks to eventually merge with a deeper low pressure
around 29.6 inches tracking across Ontario through the morning.
Southerly winds will increase along with the development of
scattered thunderstorm activity across Lake Michigan this
morning/afternoon. A cold front extending off the low tracking
across Ontario will push across Lake Michigan later this afternoon
and evening resulting in more westerly winds tonight. Then high
pressure around 30.0 inches will move across the southern tip of
Lake Michigan on Sunday, with winds turning southerly and
southwesterly as the high moves east. Southerly flow is then
expected into at least Monday, before a front becomes stationary
over the central portion of the lake through midweek.

LMZ261-362-364-366-563-565-567-868-122115-
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-
837 AM CDT Sat Jul 12 2025

SHEBOYGAN WI TO PENTWATER MI NORTH...

.REST OF TODAY...South winds 10 to 20 kt becoming southwest.
Chance of showers and slight chance of thunderstorms. Waves 2 to
4 ft.
.TONIGHT...Southwest winds 10 to 20 kt becoming west 10 to 15 kt.
Slight chance of showers and thunderstorms in the evening. Waves
1 to 3 ft.
.SUNDAY...West winds 10 to 15 kt becoming southwest 10 to 20 kt.
Waves 1 to 3 ft.
.SUNDAY NIGHT...Southwest winds 10 to 20 kt. Waves 1 to 3 ft.
.MONDAY...Southwest winds 10 to 20 kt. Waves 1 to 3 ft.
.MONDAY NIGHT...Southwest winds 10 to 20 kt becoming south 5 to
10 kt. Waves 1 to 2 ft.
.TUESDAY...South winds 10 to 15 kt increasing to 10 to 20 kt.
Waves 1 to 3 ft.
.WEDNESDAY...Northwest winds 10 to 20 kt becoming north. Chance
of showers. Waves 1 to 3 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-122115-
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-
837 AM CDT Sat Jul 12 2025

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.REST OF TODAY...Southwest winds 10 to 20 kt. Slight chance of
showers and thunderstorms through mid morning, then chance of
showers and slight chance of thunderstorms this afternoon. Waves
2 to 4 ft.
.TONIGHT...Southwest winds 10 to 15 kt becoming northwest. Slight
chance of showers in the evening. Waves 1 to 3 ft.
.SUNDAY...West winds 10 to 15 kt backing to southwest. Waves 1 to
3 ft.
.SUNDAY NIGHT...South winds 10 to 15 kt becoming southwest. Waves
1 to 3 ft.
.MONDAY...Southwest winds 10 to 15 kt becoming south 10 to 20 kt.
Waves 1 to 3 ft.
.MONDAY NIGHT...South winds 10 to 15 kt becoming southwest 5 to
10 kt. Waves 1 to 2 ft.
.TUESDAY...South winds 10 to 15 kt increasing to 10 to 20 kt.
Waves 1 to 3 ft.
.WEDNESDAY...Southwest winds 10 to 20 kt veering to northwest.
Chance of showers. Waves 1 to 3 ft.

$$

LMZ761-122115-
MAFOR 1216/
MICHIGAN NORTH 13520 14610 11610. A chance of showers this
afternoon. Waves 1 to 3 feet this afternoon and tonight. Waves 2
feet or less Sunday morning.

MICHIGAN SOUTH 12520 11510 12610 12710 11610. A chance of showers
this afternoon. Waves 1 to 3 feet this afternoon and tonight.
Waves 2 feet or less Sunday morning.

$$


Boxell

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

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