839
FZUS63 KMKX 180850
GLFLM

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

Areas of smoke will continue over the north half of the lake
tonight. Otherwise breezy southwest to west winds will develop
ahead of a cold front. The low pressure area around 29.7 inches
will track from just north of Lake Superior early this morning.
Then continues across southern Quebec this afternoon and deepen
to 29.4 inches. Its trailing cold front will track from northern
Lake Michigan Saturday morning to far southern Lake Michigan by
early afternoon. Smoke will return to Lake Michigan behind the
cold front and may become dense once again. Wildfire smoke is
expected to reduce visilibites to 1 NM at times, thus a Marine
Dense Smoke Advisory is in effect across the Lake. Breezy
northerly winds are forecast behind the cold front and will linger
into this evening.

Winds then quickly taper tonight, as high pressure around 30.1
inches moves over the northern Great Lakes. Northeast to light and
variable winds are then expected through Sunday into Sunday
night. Gusty south to southwest winds may then develop Monday into
Monday night, with gusty west to northwest winds possible into
the middle of next week.

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-
350 AM CDT Sat Jul 18 2026

SHEBOYGAN WI TO PENTWATER MI NORTH...

...DENSE SMOKE ADVISORY IN EFFECT FROM 10 AM THIS MORNING TO 7 AM
CDT MONDAY...

.TODAY...Northwest winds 15 to 25 kt becoming north to 30 kt.
Patchy smoke. Waves 4 to 6 ft occasionally to 8 ft.
.TONIGHT...North winds to 30 kt becoming northeast 10 to 15 kt.
Smoke. Waves 4 to 6 ft occasionally to 8 ft subsiding to 2 to
4 ft.
.SUNDAY...Northeast winds 5 to 10 kt becoming east late in the
morning, then veering to southwest early in the afternoon
becoming 10 to 20 kt late. Areas of smoke. Waves 1 to 3 ft
subsiding to 1 to 2 ft.
.SUNDAY NIGHT...South winds 10 to 20 kt becoming southwest 15 to
25 kt. Areas of smoke in the evening. Waves 1 to 2 ft building to
2 to 4 ft.
.MONDAY...Southwest winds to 30 kt increasing to gales to 35 kt.
Showers likely in the afternoon. Waves 4 to 6 ft occasionally to
8 ft building to 6 to 9 ft occasionally to 12 ft.
.MONDAY NIGHT...Southwest gales to 35 kt becoming west to 30 kt.
Showers with a chance of thunderstorms. Waves 6 to 9 ft
occasionally to 12 ft.
.TUESDAY...Northwest winds to 30 kt increasing to gales to 35 kt.
Waves 5 to 8 ft occasionally to 10 ft.
.WEDNESDAY...Northwest gales to 35 kt becoming north. Waves 7 to
10 ft occasionally to 13 ft subsiding to 6 to 9 ft occasionally
to 12 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-
350 AM CDT Sat Jul 18 2026

SHEBOYGAN WI TO PENTWATER MI SOUTH...

...DENSE SMOKE ADVISORY IN EFFECT FROM 3 PM THIS AFTERNOON TO
7 AM CDT MONDAY...

.TODAY...West winds 15 to 25 kt veering to north to 30 kt. Slight
chance of showers and thunderstorms this morning, then chance of
showers and slight chance of thunderstorms this afternoon. Patchy
smoke this afternoon. Waves 3 to 5 ft building to 4 to 6 ft
occasionally to 8 ft.
.TONIGHT...North winds to 30 kt becoming northeast 10 to 20 kt.
Areas of smoke. Waves 4 to 7 ft occasionally to 9 ft subsiding to
4 to 6 ft occasionally to 8 ft.
.SUNDAY...Northeast winds 10 to 15 kt backing to northwest. Areas
of smoke. Waves 3 to 5 ft subsiding to 1 to 2 ft.
.SUNDAY NIGHT...Southeast winds 10 to 15 kt becoming south 10 to
20 kt. Areas of smoke in the evening. Waves 1 to 3 ft.
.MONDAY...South winds 15 to 25 kt increasing to 30 kt. Chance of
showers in the afternoon. Waves 3 to 5 ft building to 5 to 8 ft
occasionally to 10 ft.
.MONDAY NIGHT...Southwest winds to 30 kt. Showers likely with a
chance of thunderstorms. Waves 6 to 9 ft occasionally to 12 ft.
.TUESDAY...Northwest winds to 30 kt increasing to gales to 35 kt.
Waves 5 to 8 ft occasionally to 10 ft.
.WEDNESDAY...North gales to 35 kt. Waves 8 to 12 ft occasionally
to 16 ft subsiding to 8 to 11 ft occasionally to 14 ft.

$$
LMZ761-181515-
MAFOR 1810/
MICHIGAN NORTH 11630 11730 11830 12840 11830 11820 11110. Waves 2
to 4 feet building to 3 to 5 feet today. Waves 3 to 6 feet
subsiding to 1 to 3 feet tonight.

MICHIGAN SOUTH 12630 11730 13840 11130 11120. A chance of showers
this afternoon. Waves 2 to 4 feet building to 3 to 6 feet today.
Waves 3 to 6 feet tonight.

$$


Patterson

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

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