643
FZUS63 KMKX 210003
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
703 PM CDT Mon Jul 20 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...

Wildfire smoke still encompasses parts of the lake but it is no
longer dense and no longer significantly impacting visibilities
and thus the Marine Dense Smoke Advisory is no longer in effect.

Low pressure around 29.4 inches tracking southeast across Manitoba
into Ontario will drag a cold front across the lake tonight.
South to southwest winds ahead of the front have become gusty. An
occasional gale force gust will be possible this afternoon and
evening over the northern half of the lake. Strong to severe
thunderstorms will also be possible this afternoon through tonight
across the entire lake. Winds will veer northwest behind the cold
front and remain gusty. Then winds veer due north later Tuesday
into Tuesday night with gusts to gale force possible. Heading into
Wednesday winds are expected to diminish becoming light and
variable by Wednesday night as high pressures around 30.1 inches
builds into the Great Lakes Region.

LMZ261-362-364-366-563-565-567-868-210900-
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-
703 PM CDT Mon Jul 20 2026

SHEBOYGAN WI TO PENTWATER MI NORTH...

.TONIGHT...South gales to 35 kt becoming southwest late this
evening, then diminishing to 30 kt after midnight becoming west
15 to 25 kt late. Patchy smoke this evening. Chance of showers
and thunderstorms this evening, then slight chance of
thunderstorms overnight. Waves 7 to 10 ft occasionally to 13 ft
subsiding to 4 to 6 ft occasionally to 8 ft.
.TUESDAY...West winds 15 to 25 kt becoming northwest to 30 kt,
then increasing to gales to 35 kt late. Patchy smoke in the
morning. Slight chance of showers. Waves 4 to 6 ft occasionally
to 8 ft building to 5 to 8 ft occasionally to 10 ft.
.TUESDAY NIGHT...Northwest gales to 35 kt becoming north to
30 kt. Waves 6 to 9 ft occasionally to 12 ft.
.WEDNESDAY...North winds to 30 kt becoming northwest. Waves 5 to
8 ft occasionally to 10 ft subsiding to 4 to 7 ft occasionally to
9 ft.
.WEDNESDAY NIGHT...West winds 15 to 25 kt diminishing to 5 to
10 kt overnight. Waves 2 to 4 ft subsiding to 1 to 2 ft.
.THURSDAY...West winds 10 to 20 kt becoming southwest 15 to
25 kt. Waves 1 to 3 ft.
.THURSDAY NIGHT...Southwest winds 15 to 25 kt. Waves 2 to 4 ft.
.FRIDAY...Southwest winds 10 to 20 kt increasing to 15 to 25 kt.
Waves 2 to 4 ft.
.SATURDAY...Southwest winds 15 to 25 kt becoming south to 30 kt.
Waves 2 to 4 ft building to 3 to 5 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-210900-
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-
703 PM CDT Mon Jul 20 2026

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.TONIGHT...South winds to 30 kt becoming west. Patchy smoke this
evening. Chance of showers and thunderstorms. Waves 5 to 8 ft
occasionally to 10 ft.
.TUESDAY...West winds to 30 kt becoming northwest. Slight chance
of showers in the afternoon. Waves 4 to 7 ft occasionally to 9 ft
subsiding to 4 to 6 ft occasionally to 8 ft.
.TUESDAY NIGHT...North winds to 30 kt. Waves 4 to 7 ft
occasionally to 9 ft building to 7 to 10 ft occasionally to
13 ft.
.WEDNESDAY...North winds to 30 kt. Waves 7 to 10 ft occasionally
to 13 ft.
.WEDNESDAY NIGHT...North winds to 30 kt backing to west 5 to
10 kt overnight. Waves 4 to 7 ft occasionally to 9 ft subsiding
to 2 to 4 ft.
.THURSDAY...West winds 10 to 15 kt becoming southwest 10 to
20 kt. Waves 1 to 2 ft.
.THURSDAY NIGHT...South winds 10 to 20 kt becoming southwest.
Waves 1 to 3 ft.
.FRIDAY...Southwest winds 10 to 15 kt becoming south 10 to 20 kt.
Waves 1 to 3 ft.
.SATURDAY...Southwest winds 10 to 20 kt becoming south 15 to
25 kt. Waves 1 to 2 ft building to 2 to 4 ft.

$$
LMZ761-210900-
MAFOR 2104 AMD/
MICHIGAN NORTH 11540 12630 11730 13740 11840. A chance of showers
and thunderstorms late this evening. Waves 5 to 8 feet subsiding
to 3 to 5 feet overnight. Waves 3 to 5 feet building to 4 to 7
feet Tuesday. Waves 5 to 8 feet Tuesday evening.

MICHIGAN SOUTH 11540 11640 12630 11730 12740 11840. A chance of
showers and thunderstorms overnight. Waves 4 to 7 feet subsiding
to 3 to 6 feet, then building to 4 to 7 feet overnight. Waves 4
to 7 feet subsiding to 3 to 6 feet Tuesday. Waves 4 to 7 feet
building to 6 to 9 feet Tuesday evening.

$$


WFO MKX

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

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