070
FZUS63 KMKX 151322
GLFLM

OPEN LAKE FORECAST for Lake Michigan
National Weather Service Milwaukee/Sullivan WI
822 AM 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...

30.2 inch high pressure is centered along the Ontario-Quebec
border this morning, resulting in generally light easterly winds
across the open waters. The high will progress into the
northeastern United States tonight as a cold front approaches from
the northern Great Plains, resulting in a brief period of south-
southeasterly winds this afternoon and tonight. The
aforementioned surface front will move across Lake Michigan early
Sunday morning, with northwest winds becoming established by
Sunday afternoon across the entirety of the lake. Periods of
scattered showers and thunderstorms continue today into Sunday
morning ahead of the front. 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.

LMZ261-362-364-366-563-565-567-868-152130-
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-
822 AM CDT Sat Aug 15 2026

SHEBOYGAN WI TO PENTWATER MI NORTH...

.REST OF TODAY...East winds 10 to 20 kt. Waves 3 to 5 ft.
.TONIGHT...East winds 10 to 20 kt veering to south 10 to 15 kt.
Slight chance of showers and thunderstorms overnight. Waves 1 to
3 ft subsiding to 1 to 2 ft.
.SUNDAY...West winds 10 to 15 kt becoming northwest 10 to 20 kt
late in the morning, then increasing to 15 to 25 kt early in the
afternoon becoming north to 30 kt late. Chance of showers in the
morning. Waves 1 to 2 ft building to 2 to 4 ft.
.SUNDAY NIGHT...North winds to 30 kt diminishing to 10 to 20 kt
overnight. Waves 2 to 4 ft.
.MONDAY...Northwest winds 10 to 15 kt backing to southwest 10 to
20 kt. Waves 1 to 3 ft.
.MONDAY NIGHT...Southwest winds 10 to 15 kt increasing to 10 to
20 kt. Waves 1 to 3 ft.
.TUESDAY...Southwest winds 15 to 25 kt increasing to 30 kt.
Chance of showers. Waves 2 to 4 ft.
.WEDNESDAY...North winds 15 to 25 kt increasing to 30 kt. Chance
of showers. Waves 3 to 5 ft.

$$

LMZ080-669-671-673-675-777-779-870-872-874-876-878-152130-
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-
822 AM CDT Sat Aug 15 2026

SHEBOYGAN WI TO PENTWATER MI SOUTH...

.REST OF TODAY...Southeast winds 10 to 20 kt. Scattered showers
with isolated thunderstorms. Waves 3 to 5 ft.
.TONIGHT...Southeast winds 10 to 15 kt becoming southwest 5 to
10 kt. Slight chance of showers and thunderstorms overnight.
Waves 2 to 4 ft subsiding to 1 to 2 ft.
.SUNDAY...West winds 10 to 20 kt becoming northwest 10 to 15 kt.
Chance of showers in the morning. Waves 1 to 2 ft.
.SUNDAY NIGHT...North winds 10 to 20 kt. 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...South winds 10 to 15 kt becoming southwest. Waves
1 to 2 ft building to 1 to 3 ft.
.TUESDAY...Southwest winds 10 to 20 kt. Waves 2 to 4 ft.
.WEDNESDAY...West winds 15 to 25 kt becoming north to 30 kt.
Chance of showers and thunderstorms. Waves 4 to 6 ft occasionally
to 8 ft.

$$

LMZ761-152130-
MAFOR 1516/
MICHIGAN NORTH 13220 12320 11410 11510 11710. A chance of showers
Sunday morning. Waves 2 to 4 feet this afternoon. Waves 1 to 3
feet tonight. Waves 1 foot or less Sunday morning.

MICHIGAN SOUTH 12320 19326 11310 11300 12400 11510 11620. Waves 2
to 4 feet this afternoon. Waves 1 to 3 feet subsiding to 1 foot
or less tonight. Waves 2 feet or less Sunday morning.

$$


Quigley

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

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