309
FZUS63 KMKX 160208
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
908 PM CDT Sat Aug 15 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 in Manitoba will move northeast
toward James Bay tonight into Sunday morning. An associated cold
front is expected to move across the lake Sunday. Southeast winds
out ahead of the front will turn to northwesterly and become
breezy behind the front. Periods of scattered showers and
thunderstorms will be possible along and ahead of the front
tonight through Sunday morning. Severe weather is not
anticipated.

A new area of 30.1 inch high pressure will build in from the
northern Great Plains late Sunday night into Monday, bringing
light and variable winds to the waters through the majority of
Monday and Monday evening. A slow-moving cold front will approach
from the northern Great Plains Tuesday into Wednesday, bringing
increasing southwest winds and chances for thunderstorms. Precise
timing details will continue to be refined over coming forecasts,
though it does appear that a few stronger storms could be possible
over the southern half of the waters Tuesday afternoon & night.
Winds will trend light and variable behind the front from
Wednesday night through the end of next week.

LMZ261-362-364-366-563-565-567-868-160930-
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-
908 PM CDT Sat Aug 15 2026

SHEBOYGAN WI TO PENTWATER MI NORTH...

.REST OF TONIGHT...East winds 10 to 20 kt veering to south.
Slight chance of showers overnight. Waves 1 to 3 ft.
.SUNDAY...Southwest winds 10 to 15 kt increasing to 10 to 20 kt
late in the morning, then becoming west early in the afternoon
becoming north 15 to 25 kt late. Chance of showers and slight
chance of thunderstorms in the morning, then slight chance of
showers in the afternoon. Waves 1 to 2 ft building to 2 to 4 ft.
.SUNDAY NIGHT...North winds 15 to 25 kt becoming northwest 10 to
15 kt. Waves 2 to 4 ft subsiding to 1 to 3 ft.
.MONDAY...Northwest winds 10 to 15 kt backing to southwest 10 to
20 kt. Waves 1 to 3 ft.
.MONDAY NIGHT...South winds 10 to 20 kt becoming southwest. Waves
1 to 2 ft building to 2 to 4 ft.
.TUESDAY...Southwest winds 15 to 25 kt. Chance of showers and
thunderstorms in the afternoon. Waves 2 to 4 ft.
.TUESDAY NIGHT...Northwest winds 10 to 20 kt becoming north.
Chance of showers. Waves 2 to 4 ft.
.WEDNESDAY...North winds 10 to 20 kt increasing to 15 to 25 kt.
Waves 1 to 3 ft.
.THURSDAY...North winds 10 to 15 kt backing to southwest 10 to
20 kt. Waves 1 to 2 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-160930-
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-
908 PM CDT Sat Aug 15 2026

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.REST OF TONIGHT...Southeast winds 5 to 10 kt becoming south
10 to 15 kt. Chance of sprinkles through early evening, then
chance of showers and thunderstorms overnight. Waves 1 to 3 ft
subsiding to 1 to 2 ft.
.SUNDAY...Southwest winds 10 to 15 kt becoming northwest 10 to
20 kt. Chance of showers and slight chance of thunderstorms in
the morning, then slight chance of showers and thunderstorms in
the afternoon. Waves 1 to 2 ft.
.SUNDAY NIGHT...Northwest winds 10 to 20 kt becoming north. Waves
2 to 4 ft.
.MONDAY...North winds 10 to 15 kt becoming northwest 10 to 20 kt.
Waves 2 to 4 ft.
.MONDAY NIGHT...Southwest winds 10 to 20 kt. Waves 1 to 2 ft
building to 2 to 4 ft.
.TUESDAY...Southwest winds 10 to 20 kt. Waves 2 to 4 ft.
.TUESDAY NIGHT...Southwest winds 10 to 20 kt becoming northwest.
Showers likely with a chance of thunderstorms. Waves 2 to 4 ft.
.WEDNESDAY...North winds 10 to 20 kt increasing to 30 kt. Chance
of showers. Waves 2 to 4 ft.
.THURSDAY...Northeast winds 10 to 15 kt becoming east 10 to
20 kt. Waves 1 to 3 ft.

$$

LMZ761-160930-
MAFOR 1604/
MICHIGAN NORTH 11320 11420 11410 11510 11620 11730 12830. A
chance of showers Sunday morning. Waves 2 feet or less overnight.
Waves 1 to 3 feet Sunday. Waves 2 to 4 feet Sunday evening.

MICHIGAN SOUTH 11400 11410 11510 13610 11710 11820. A chance of
showers late this evening, then a chance of showers and
thunderstorms overnight. A chance of showers Sunday morning.
Waves 2 feet or less.

$$


Patterson

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

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