032
FZUS63 KMKX 180826
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
326 AM CDT Mon Aug 18 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 will continue to exit toward the Atlantic tonight
with high pressure around 30.4 inches developing across Ontario. A
developing low pressure over South Dakota will move into southern
Minnesota overnight. A front associated with this low pressure
will gradually move southeast across the region, clearing the
south end of Lake Michigan by midday Tuesday. This front will
bring multiple rounds of showers and storms from tonight through
Monday night.

Winds will shift northeast to southeast this morning. A small
craft advisory remains in effect until 1 PM today for these
onshore winds and resulting waves. After the front exits the area,
winds will shift to the north from Tuesday through Friday.

LMZ261-362-364-366-563-565-567-868-181515-
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-
326 AM CDT Mon Aug 18 2025

SHEBOYGAN WI TO PENTWATER MI NORTH...

.TODAY...Southeast winds 15 to 25 kt. Slight chance of showers
this morning, then chance of showers and slight chance of
thunderstorms this afternoon. Waves 4 to 6 ft occasionally to
8 ft subsiding to 3 to 5 ft.
.TONIGHT...Southeast winds 15 to 25 kt becoming south 10 to
20 kt. Chance of showers and thunderstorms. Waves 2 to 4 ft.
.TUESDAY...South winds 10 to 20 kt veering to northwest. Waves
2 to 4 ft.
.TUESDAY NIGHT...North winds 10 to 20 kt. Waves 2 to 4 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 increasing to 10 to 15 kt.
Waves 1 to 2 ft.
.FRIDAY...Southwest winds 10 to 20 kt. Waves 1 to 3 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-181515-
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-
326 AM CDT Mon Aug 18 2025

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.TODAY...Southeast winds 15 to 25 kt diminishing to 10 to 20 kt.
Slight chance of showers this morning, then chance of showers and
slight chance of thunderstorms this afternoon. Waves 4 to 7 ft
occasionally to 9 ft subsiding to 3 to 5 ft.
.TONIGHT...Southeast winds 10 to 20 kt becoming south. Chance of
showers and thunderstorms. Waves 2 to 4 ft.
.TUESDAY...Southwest winds 10 to 20 kt veering to northwest.
Chance of showers in the morning. Waves 2 to 4 ft subsiding to
1 to 3 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 5 to 8 ft
occasionally to 10 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...Southwest winds 10 to 15 kt. Waves 1 to 2 ft.

$$

LMZ761-181515-
MAFOR 1810/
MICHIGAN NORTH 14330 11336 11330 11320 11420. A chance of
thunderstorms tonight. Waves 3 to 6 feet subsiding to 2 to 4 feet
today. Waves 2 to 4 feet subsiding to 1 to 3 feet tonight.

MICHIGAN SOUTH 13330 13320 12420. A chance of showers this
afternoon. A chance of showers and thunderstorms tonight. Waves 4
to 7 feet subsiding to 2 to 4 feet today. Waves 2 to 4 feet
tonight.

$$


Kuroski

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

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