612
FZUS63 KMKX 181359
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
859 AM CDT Fri Sep 18 2026

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 29.9 inches will develop near the Missouri
River this afternoon, moving over or just south of waters during
the day on Saturday. Winds will veer east southeasterly ahead of
the low, becoming gusty at times. A few gusts could approach gale
thresholds, particularly tonight and Saturday morning. Areas of
widespread showers and thunderstorms will accompany the passing
area of low pressure tonight through at least Saturday night.

Winds will trend northeasterly Sunday through Monday night, as
the aforementioned area of low pressure slowly moves into the Ohio
River Valley. Additional rain showers will accompany the passing
low. High pressure around 30.5 inches will concurrently slide
into Ontario from the Canadian Great Plains, with gusty winds
expected through most of the late weekend to early week time
frame. Similar to Saturday, gusts could occasionally approach gale
thresholds during the Sunday into Monday night time frame. Winds
will steadily taper Tuesday through Wednesday, as a new area of
high pressure around 30.3 inches builds into northern Wisconsin.

LMZ261-362-364-366-563-565-567-868-182130-
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-
859 AM CDT Fri Sep 18 2026

SHEBOYGAN WI TO PENTWATER MI NORTH...

.REST OF TODAY...Northeast winds 10 to 20 kt. Slight chance of
showers this afternoon. Waves 2 to 4 ft.
.TONIGHT...Northeast winds 10 to 20 kt becoming southeast 15 to
25 kt. Chance of showers. Waves 2 to 4 ft building to 3 to 5 ft.
.SATURDAY...Southeast winds 15 to 25 kt becoming east. Chance of
showers. Waves 4 to 7 ft occasionally to 9 ft.
.SATURDAY NIGHT...East winds 10 to 20 kt becoming northeast.
Chance of showers. Waves 3 to 5 ft subsiding to 2 to 4 ft.
.SUNDAY...Northeast winds to 30 kt. Waves 4 to 6 ft occasionally
to 8 ft building to 6 to 9 ft occasionally to 12 ft.
.SUNDAY NIGHT...Northeast winds to 30 kt becoming east 15 to
25 kt. Waves 6 to 9 ft occasionally to 12 ft.
.MONDAY...East winds to 30 kt becoming northeast. Waves 4 to 7 ft
occasionally to 9 ft.
.TUESDAY...Northeast winds 15 to 25 kt increasing to 30 kt. Waves
4 to 6 ft occasionally to 8 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-182130-
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-
859 AM CDT Fri Sep 18 2026

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.REST OF TODAY...Northeast winds 10 to 20 kt. Waves 3 to 5 ft.
.TONIGHT...Northeast winds 10 to 20 kt becoming east 15 to 25 kt
late in the evening, then increasing to 30 kt after midnight
becoming east to 30 kt late. Chance of showers in the evening,
then showers and slight chance of thunderstorms overnight. Waves
3 to 5 ft building to 5 to 8 ft occasionally to 10 ft.
.SATURDAY...Southeast winds to 30 kt becoming east 15 to 25 kt.
Showers with a chance of thunderstorms in the morning, then
chance of showers in the afternoon. Waves 6 to 9 ft occasionally
to 12 ft.
.SATURDAY NIGHT...East winds 15 to 25 kt becoming northeast 10 to
20 kt. Chance of showers in the evening, then showers likely
overnight. Waves 4 to 7 ft occasionally to 9 ft subsiding to 4 to
6 ft occasionally to 8 ft.
.SUNDAY...Northeast winds to 30 kt increasing to gales to 35 kt.
Chance of showers. Waves 5 to 8 ft occasionally to 10 ft building
to 8 to 11 ft occasionally to 14 ft.
.SUNDAY NIGHT...Northeast gales to 35 kt becoming east to 30 kt.
Chance of showers. Waves 8 to 11 ft occasionally to 14 ft
subsiding to 7 to 10 ft occasionally to 13 ft.
.MONDAY...East winds to 30 kt becoming northeast gales to 35 kt.
Chance of showers. Waves 8 to 12 ft occasionally to 16 ft
building to 10 to 14 ft occasionally to 18 ft.
.TUESDAY...Northeast winds to 30 kt. Chance of showers. Waves
7 to 10 ft occasionally to 13 ft.

$$

LMZ761-182130-
MAFOR 1816/
MICHIGAN NORTH 12110 11120 12220 11320 12330. A chance of showers
tonight and Saturday morning. Waves 1 to 3 feet this afternoon.
Waves 1 to 3 feet building to 3 to 5 feet tonight. Waves 3 to 6
feet Saturday morning.

MICHIGAN SOUTH 11120 11110 11120 12230 12246 11346. A chance of
thunderstorms Saturday morning. Waves 2 to 4 feet this afternoon.
Waves 3 to 6 feet building to 5 to 8 feet tonight. Waves 5 to 9
feet Saturday morning.

$$


Wagner

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

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