825
FZUS63 KMKX 172004
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
304 PM CDT Sun Aug 17 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...

Low pressure around 29.4 inches will continue toward the Atlantic
tonight with high pressure around 30.4 inches developing across
Ontario. The low will continue to have an associated front draped
across parts of the Great Lakes region which will remain the
focus for thunderstorm development through Tuesday morning.
Developing low pressure around 29.8 inches over South Dakota will
move into southern Minnesota overnight. This will be the renewed
focus for storm development late tonight throughout Monday.

Winds will shift north to northeast today and southeast Monday
morning. A period of south are possible Monday morning. Once the
next system pushes out we will see a return to more northerly
flow across the lake from Tuesday through Friday.

LMZ261-362-364-366-563-565-567-868-180315-
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-
304 PM CDT Sun Aug 17 2025

SHEBOYGAN WI TO PENTWATER MI NORTH...

.TONIGHT...Northeast winds 15 to 25 kt becoming southeast. Waves
4 to 7 ft occasionally to 9 ft.
.MONDAY...Southeast winds 15 to 25 kt. Slight chance of showers
and thunderstorms in the morning, then chance of showers and
thunderstorms in the afternoon. Waves 4 to 6 ft occasionally to
8 ft subsiding to 3 to 5 ft.
.MONDAY NIGHT...Southeast winds 15 to 25 kt becoming south 10 to
20 kt. Showers and thunderstorms likely in the evening, then
showers likely with a chance of thunderstorms overnight. Waves
3 to 5 ft.
.TUESDAY...Southwest winds 10 to 20 kt veering to north. Chance
of showers. Waves 3 to 5 ft.
.TUESDAY NIGHT...North winds 10 to 20 kt. Waves 1 to 3 ft
building to 3 to 5 ft.
.WEDNESDAY...North winds 10 to 20 kt increasing to 15 to 25 kt.
Waves 3 to 5 ft.
.WEDNESDAY NIGHT...Northeast winds 15 to 25 kt diminishing to
10 to 20 kt. Waves 3 to 5 ft subsiding to 2 to 4 ft.
.THURSDAY...Northeast winds 5 to 10 kt becoming north 10 to
20 kt. Waves 1 to 2 ft.
.FRIDAY...Southwest winds 10 to 20 kt. Waves 1 to 3 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-180315-
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-
304 PM CDT Sun Aug 17 2025

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.TONIGHT...North winds 10 to 20 kt veering to southeast 15 to
25 kt. Waves 4 to 7 ft occasionally to 9 ft.
.MONDAY...Southeast winds 15 to 25 kt diminishing to 10 to 20 kt.
Slight chance of showers and thunderstorms in the morning, then
chance of showers and thunderstorms in the afternoon. Waves 4 to
7 ft occasionally to 9 ft subsiding to 4 to 6 ft occasionally to
8 ft.
.MONDAY NIGHT...Southeast winds 10 to 20 kt becoming south.
Chance of showers and thunderstorms in the evening, then showers
likely with a chance of thunderstorms overnight. Waves 3 to 5 ft.
.TUESDAY...Southwest winds 10 to 20 kt veering to northwest.
Chance of showers and thunderstorms in the morning, then chance
of showers in the afternoon. Waves 3 to 5 ft.
.TUESDAY NIGHT...North winds 10 to 20 kt. Waves 2 to 4 ft
building to 4 to 6 ft occasionally to 8 ft.
.WEDNESDAY...North winds 15 to 25 kt. Waves 4 to 7 ft
occasionally to 9 ft.
.WEDNESDAY NIGHT...North winds 15 to 25 kt becoming northeast
10 to 20 kt. Waves 5 to 8 ft occasionally to 10 ft subsiding to
4 to 7 ft occasionally to 9 ft.
.THURSDAY...Northeast winds 10 to 15 kt becoming north 10 to
20 kt. Waves 3 to 5 ft subsiding to 1 to 3 ft.
.FRIDAY...South winds 5 to 10 kt becoming southwest 10 to 15 kt.
Waves 1 to 2 ft.

$$

LMZ761-180315-
MAFOR 1722/
MICHIGAN NORTH 12130 11230 12330 12320 11330. A chance of showers
and thunderstorms Monday afternoon. Waves 3 to 6 feet tonight.
Waves 3 to 6 feet subsiding to 2 to 4 feet Monday.

MICHIGAN SOUTH 11820 11120 11230 12330 13320. Waves 3 to 6 feet
tonight. Waves 3 to 6 feet subsiding to 2 to 4 feet Monday.

$$


Cronce

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

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