fzus61 kbuf 202002
glflo 
expires:202608210300;;067417

open lake forecast for lake ontario
national weather service buffalo ny
402 pm edt thu aug 20 2026

for waters beyond five nautical miles of shore on lake ontario

waves are the significant wave height - the average of the highest
1/3 of the wave spectrum. occasional wave height is the average of
the highest 1/10 of the wave spectrum.

.synopsis...
a ridge averaging 30.1 inches affects lake ontario through saturday 
as the embedded high pressure center moves from the upper great 
lakes toward the canadian maritimes. a warm front should sweep 
northward across lake ontario saturday night and a cold front should 
sweep eastward across the lake late saturday night through sunday as 
a low of 29.7 inches moves from the upper great lakes toward 
southern quebec. behind the low, a weak trough averaging 29.9 inches 
should linger over lake ontario through monday before a ridge 
averaging 30.0 inches builds from near the ohio valley on tuesday.


loz062-210300-
lake ontario open waters from the niagara river to hamlin beach-
402 pm edt thu aug 20 2026

.tonight...northwest winds 10 knots or less becoming northeast.
waves 2 feet or less. 
.friday...east winds 10 knots or less. waves 1 foot or less. 
.friday night...east winds 5 to 10 knots becoming southeast.
waves 2 feet or less. 
.saturday...southeast winds 10 knots or less becoming east. a
chance of showers and thunderstorms in the afternoon. waves
1 foot or less. 
.saturday night...southeast winds 5 to 10 knots becoming
southwest. showers with a chance of thunderstorms in the evening,
then showers overnight. waves 1 to 2 feet. 
.sunday...west winds 15 to 20 knots. showers likely with a chance
of thunderstorms. waves 1 to 3 feet building to 2 to 4 feet. 
.monday...west winds 15 to 20 knots diminishing to 10 to
15 knots. a chance of showers during the day. waves 2 to 4 feet
subsiding to 1 to 3 feet. 
.tuesday...west winds 5 to 15 knots becoming southwest. waves
1 to 2 feet. 

winds and waves higher in and near thunderstorms.

$$

fzus61 kbuf 202002
glflo 
expires:202608210300;;067418

open lake forecast for lake ontario
national weather service buffalo ny
402 pm edt thu aug 20 2026

for waters beyond five nautical miles of shore on lake ontario

waves are the significant wave height - the average of the highest
1/3 of the wave spectrum. occasional wave height is the average of
the highest 1/10 of the wave spectrum.

.synopsis...
a ridge averaging 30.1 inches affects lake ontario through saturday 
as the embedded high pressure center moves from the upper great 
lakes toward the canadian maritimes. a warm front should sweep 
northward across lake ontario saturday night and a cold front should 
sweep eastward across the lake late saturday night through sunday as 
a low of 29.7 inches moves from the upper great lakes toward 
southern quebec. behind the low, a weak trough averaging 29.9 inches 
should linger over lake ontario through monday before a ridge 
averaging 30.0 inches builds from near the ohio valley on tuesday.


loz063>065-210300-
lake ontario open waters from hamlin beach to the saint lawrence
river-
402 pm edt thu aug 20 2026

.tonight...northwest winds 5 to 15 knots becoming east. waves
2 feet or less. 
.friday...east winds 10 knots or less becoming northeast. waves
1 foot or less. 
.friday night...northeast winds 5 to 10 knots becoming southeast.
waves 1 foot or less. 
.saturday...southeast winds 5 to 15 knots. a chance of showers
and thunderstorms in the afternoon. waves 2 feet or less. 
.saturday night...southeast winds 5 to 15 knots becoming south
15 to 20 knots. showers likely with a chance of thunderstorms in
the evening, then showers likely overnight. waves 1 to 3 feet. 
.sunday...southwest winds 15 to 20 knots becoming west. showers
with a chance of thunderstorms. waves 1 to 3 feet building to
2 to 4 feet. 
.monday...west winds 15 to 25 knots diminishing to 10 to
15 knots. showers likely during the day, then a chance of showers
monday night. waves 2 to 4 feet subsiding to 1 to 3 feet. 
.tuesday...west winds 5 to 15 knots becoming southwest. waves
1 to 3 feet. 

winds and waves higher in and near thunderstorms.

$$

fzus61 kcle 201943
glfle 
expires:202608210215;;066819

open lake forecast for lake erie
national weather service cleveland oh
343 pm edt thu aug 20 2026

for waters beyond five nautical miles of shore on lake erie

waves are the significant wave height - the average of the highest
1/3 of the wave spectrum. occasional wave height is the average of
the highest 1/10 of the wave spectrum.

.synopsis...
high pressure 30.10 inches builds into the region through friday.
low pressure 29.90 inches moves into the great lakes region on 
saturday. the low will drag a cold front across the lake saturday
night into sunday.


lez162>164-210215-
detroit river lt. to maumee bay oh to reno beach oh beyond 5nm
offshoreline to us-canadian border-
reno beach to the islands oh beyond 5nm off shoreline to us-
canadian border-
the islands to vermilion oh beyond 5 nm off shoreline to us-
canadian border-
343 pm edt thu aug 20 2026

.tonight...east winds 5 to 15 knots. waves 1 to 3 feet. 
.friday...east winds 5 to 10 knots. waves 2 feet or less. 
.friday night...east winds 5 to 10 knots becoming south. waves
1 foot or less. 
.saturday...southwest winds 5 to 10 knots. a chance of showers
and thunderstorms in the afternoon. waves 1 foot or less. 
.saturday night...west winds 10 to 15 knots becoming northwest.
showers with a chance of thunderstorms in the evening, then a
chance of showers overnight. waves 1 to 3 feet. 
.sunday...northwest winds 15 to 20 knots diminishing to 10 to
15 knots. waves 1 to 3 feet. 
.monday...northwest winds 5 to 15 knots becoming west. waves
2 feet or less. 
.tuesday...west winds 5 to 10 knots becoming southwest. waves
1 foot or less. 

winds and waves higher in and near thunderstorms.

$$

fzus61 kcle 201943
glfle 
expires:202608210215;;066820

open lake forecast for lake erie
national weather service cleveland oh
343 pm edt thu aug 20 2026

for waters beyond five nautical miles of shore on lake erie

waves are the significant wave height - the average of the highest
1/3 of the wave spectrum. occasional wave height is the average of
the highest 1/10 of the wave spectrum.

.synopsis...
high pressure 30.10 inches builds into the region through friday.
low pressure 29.90 inches moves into the great lakes region on 
saturday. the low will drag a cold front across the lake saturday
night into sunday.


lez165>167-210215-
vermilion to avon point oh beyond 5 nm off shoreline to us-
canadian border-
avon point to willowick oh beyond 5 nm off shoreline to us-
canadian border-willowick to geneva-on-the-
lake oh beyond 5nm off shoreline to us-canadian border-
343 pm edt thu aug 20 2026

.tonight...northeast winds 5 to 15 knots becoming east. waves
1 to 3 feet. 
.friday...southeast winds 5 to 10 knots becoming northeast. waves
2 feet or less. 
.friday night...east winds 5 to 10 knots becoming south. waves
1 to 2 feet. 
.saturday...south winds 10 to 15 knots becoming southwest. a
chance of showers and thunderstorms in the afternoon. waves 1 to
2 feet. 
.saturday night...west winds 10 to 15 knots becoming northwest.
showers with a chance of thunderstorms in the evening, then
showers overnight. waves 1 to 3 feet. 
.sunday...northwest winds 15 to 20 knots diminishing to 10 to
15 knots. a chance of showers and thunderstorms during the day,
then a chance of showers sunday night. waves 2 to 4 feet
subsiding to 1 to 3 feet. 
.monday...northwest winds 15 to 20 knots becoming west 5 to
15 knots. waves 1 to 3 feet. 
.tuesday...west winds 5 to 10 knots becoming south. waves 1 foot
or less. 

winds and waves higher in and near thunderstorms.

$$

fzus61 kcle 201943
glfle 
expires:202608210215;;066821

open lake forecast for lake erie
national weather service cleveland oh
343 pm edt thu aug 20 2026

for waters beyond five nautical miles of shore on lake erie

waves are the significant wave height - the average of the highest
1/3 of the wave spectrum. occasional wave height is the average of
the highest 1/10 of the wave spectrum.

.synopsis...
high pressure 30.10 inches builds into the region through friday.
low pressure 29.90 inches moves into the great lakes region on 
saturday. the low will drag a cold front across the lake saturday
night into sunday.


lez061-168-169-210215-
ripley to buffalo ny extending from 5nm off shoreline to us-
canadian border-geneva-on-the-
lake to conneaut oh beyond 5 nm off shoreline to us-
canadian border-
conneaut oh to ripley ny beyond 5 nm off shoreline to us-
canadian border-
343 pm edt thu aug 20 2026

.tonight...northeast winds 5 to 15 knots becoming east. waves
2 feet or less. 
.friday...east winds 5 to 10 knots becoming northeast. waves
1 foot or less. 
.friday night...northeast winds 5 to 10 knots becoming south.
waves 1 foot or less. 
.saturday...south winds 5 to 10 knots becoming west. a chance of
showers and thunderstorms in the afternoon. waves 2 feet or less.
.saturday night...southwest winds 10 to 15 knots becoming
northwest. showers with a chance of thunderstorms. waves 1 to
3 feet. 
.sunday...northwest winds 15 to 20 knots diminishing to 10 to
15 knots. showers likely with a chance of thunderstorms during
the day, then a chance of showers sunday night. waves 2 to 4 feet
subsiding to 1 to 3 feet. 
.monday...northwest winds 5 to 15 knots becoming west. waves 1 to
3 feet. 
.tuesday...west winds 5 to 10 knots becoming south. waves 1 foot
or less. 

winds and waves higher in and near thunderstorms.

$$

fzus63 kdtx 201941
glfsc 
expires:202608210345;;066731

lake st clair forecast
national weather service detroit/pontiac mi
341 pm edt thu aug 20 2026

waves are the significant wave height - the average of the highest
1/3 of the wave spectrum. occasional wave height is the average of
the highest 1/10 of the wave spectrum.

.synopsis...high pressure, 30.00 inches, builds into the great
lakes today and friday. the next low pressure system then arrives
saturday, dragging a cold front across the area and increasing
shower and thunderstorm chances. post-frontal northwest flow
leads to gusty winds sunday.


lcz460-210345-
lake st clair-
341 pm edt thu aug 20 2026

.tonight...northeast winds 10 to 15 knots becoming east 5 to 10
knots after midnight. mostly clear. waves 2 feet or less.
.friday...southeast winds 5 to 10 knots. mostly sunny. waves 2 feet
or less.
.friday night...southeast winds 10 to 15 knots diminishing to 5 to
10 knots in the late evening and overnight. partly cloudy. a chance
of light showers by midnight. waves 2 feet or less.
.saturday...light and variable winds becoming southwest 5 to 10
knots in the late morning and afternoon. a chance of light showers
until late afternoon...then showers and a chance of thunderstorms
early in the afternoon. waves 2 feet or less.
.saturday night...northwest winds 10 to 15 knots increasing to 15 to
20 knots in the late evening and overnight. light showers and a
chance of thunderstorms early in the evening...then partly cloudy in
the late evening and overnight. waves 2 feet or less.
.sunday...northwest winds 15 to 20 knots becoming north 10 to 15
knots in the evening. partly sunny in the morning...then partly
cloudy with a chance of light showers in the afternoon and evening.
waves 1 to 3 feet.
.monday...north winds 10 to 15 knots. mostly clear. waves 2 feet or
less.
.tuesday...south winds 5 to 10 knots. mostly clear. waves 2 feet or
less.

$$

fzus63 kdtx 201940
glflh 
expires:202608210345;;066728

open lake forecast for lake huron
national weather service detroit/pontiac mi
340 pm edt thu aug 20 2026

for waters beyond five nautical miles off shore on lake huron

waves are the significant wave height - the average of the highest
1/3 of the wave spectrum. occasional wave height is the average of
the highest 1/10 of the wave spectrum.

.synopsis...high pressure, 30.00 inches, builds into the great
lakes today and friday. the next low pressure system then arrives
saturday, dragging a cold front across the area and increasing
shower and thunderstorm chances. post-frontal northwest flow
leads to gusty winds sunday.


lhz462>464-210345-
lake huron from port austin to harbor beach beyond 5nm off shore-
lake huron from harbor beach to port sanilac beyond 5nm off shore-
lake huron from port sanilac to port huron beyond 5nm off shore-
340 pm edt thu aug 20 2026

.tonight...northeast winds 5 to 10 knots veering to the east
after midnight. waves 2 feet or less. 
.friday...southeast winds 5 to 10 knots. waves 2 feet or less. 
.friday night...southeast winds 5 to 10 knots increasing to 10 to
15 knots in the late evening and overnight. waves 1 to 3 feet. 
.saturday...south winds 5 to 10 knots. a chance of showers in the
morning...then showers and a chance of thunderstorms in the
afternoon. a chance of waterspouts. waves 1 to 3 feet. 
.saturday night...west winds 5 to 10 knots becoming northwest
15 to 20 knots in the late evening and overnight. showers likely
and a chance of thunderstorms in the evening...then showers
likely after midnight. waves 1 to 3 feet building to 4 to 6 feet
in the late evening and overnight. waves occasionally around
8 feet. 
.sunday...northwest winds 15 to 20 knots increasing to 20 to
25 knots late in the morning...then decreasing to 15 to 20 knots
late in the evening. gusts to 30 knots. a chance of waterspouts.
a chance of showers. a chance of thunderstorms late in the
afternoon. waves 6 to 9 feet. waves occasionally around 11 feet. 
.monday...northwest winds 15 to 20 knots decreasing to 5 to
10 knots . waves 4 to 6 feet subsiding to 1 to 3 feet by
midnight. waves occasionally around 8 feet. 
.tuesday...west winds 5 to 10 knots backing to the southwest
early in the evening...then becoming south 10 to 15 knots by
midnight. waves 2 feet or less. 


$$

fzus63 kdtx 201940
glflh 
expires:202608210345;;066727

open lake forecast for lake huron
national weather service detroit/pontiac mi
340 pm edt thu aug 20 2026

for waters beyond five nautical miles off shore on lake huron

waves are the significant wave height - the average of the highest
1/3 of the wave spectrum. occasional wave height is the average of
the highest 1/10 of the wave spectrum.

.synopsis...high pressure, 30.00 inches, builds into the great
lakes today and friday. the next low pressure system then arrives
saturday, dragging a cold front across the area and increasing
shower and thunderstorm chances. post-frontal northwest flow
leads to gusty winds sunday.


lhz361>363-210345-
lake huron from 5nm east of mackinac bridge to presque isle lt
beyond 5 nm off shore-
lake huron from presque isle light to sturgeon point mi beyond
5nm off shore-
lake huron from sturgeon point to alabaster mi beyond 5nm off
shore-
340 pm edt thu aug 20 2026

.tonight...light and variable winds becoming east 5 to 10 knots
by midnight...then veering to the southeast early in the morning.
waves 2 feet or less. 
.friday...south winds 5 to 10 knots becoming southeast 10 to
15 knots in the late morning and afternoon. a chance of showers
in the afternoon. waves 1 to 3 feet building to 2 to 4 feet in
the afternoon. 
.friday night...southeast winds 10 to 15 knots. a chance of
showers. a chance of waterspouts after midnight. waves 3 to
5 feet. 
.saturday...south winds 5 to 10 knots. a chance of waterspouts in
the morning. showers in the morning...then showers and a chance
of thunderstorms in the afternoon. waves 2 to 4 feet subsiding to
1 to 3 feet in the late morning and afternoon. 
.saturday night...northwest winds 10 to 15 knots increasing to
15 to 20 knots in the late evening and overnight. a chance of
showers. waves 4 to 6 feet. waves occasionally around 8 feet. 
.sunday...northwest winds 20 to 25 knots decreasing to 15 to
20 knots late in the evening. gusts to 30 knots. a chance of 
showers in the morning. a chance of waterspouts in the morning. 
waves 8 to 12 feet. waves occasionally around 15 feet. 
.monday...northwest winds 15 to 20 knots becoming west 5 to
10 knots. waves 4 to 6 feet. waves occasionally around 8 feet. 
.tuesday...west winds 5 to 10 knots backing to the southwest
until early evening...then becoming south 10 to 15 knots by
midnight. waves 1 to 3 feet. 


$$

fzus63 kmkx 202059
glflm 
expires:202608210315;;069692

open lake forecast for lake michigan
national weather service milwaukee/sullivan wi
359 pm cdt thu aug 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...

high pressure around 30.0 inches continues to track through the 
western great lakes region this afternoon. as the high pressure 
exits to the southeast later tonight, south to southwest winds 
will develop. theses winds will increase for friday, along with 
shower and thunderstorm chances, as low pressure around 29.8 
inches moves across the region and drags a cold front through lake
michigan. gusty winds will then shift to the northwest later 
friday night into saturday after the front exits. another high 
pressure system around 30.2 inches is expected to build into the 
region later this weekend, which may maintain gusty northerly 
winds as it moves in.


lmz080-669-671-673-675-777-779-870-872-874-876-878-210315-
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-
359 pm cdt thu aug 20 2026

sheboygan wi to pentwater mi south...

.tonight...north winds 10 to 15 kt backing to south 10 to 20 kt.
waves 1 to 2 ft. 
.friday...south winds 10 to 20 kt increasing to 15 to 25 kt.
slight chance of showers and thunderstorms in the afternoon.
waves 3 to 5 ft. 
.friday night...south winds 10 to 20 kt veering to west. chance
of showers in the evening, then chance of showers and
thunderstorms overnight. waves 3 to 5 ft subsiding to 1 to 3 ft. 
.saturday...northwest winds 15 to 25 kt becoming north. waves
4 to 6 ft occasionally to 8 ft. 
.saturday night...north winds 15 to 25 kt. waves 4 to 6 ft
occasionally to 8 ft building to 4 to 7 ft occasionally to 9 ft. 
.sunday...north winds to 30 kt. waves 5 to 8 ft occasionally to
10 ft. 
.sunday night...north winds 15 to 25 kt diminishing to 10 to
15 kt. waves 4 to 6 ft occasionally to 8 ft subsiding to 2 to
4 ft. 
.monday...northwest winds 10 to 20 kt becoming north. waves 1 to
3 ft. 
.tuesday...south winds 10 to 20 kt increasing to 15 to 25 kt.
waves 1 to 3 ft building to 3 to 5 ft.  

$$

fzus63 kmkx 202059
glflm 
expires:202608210315;;069691

open lake forecast for lake michigan
national weather service milwaukee/sullivan wi
359 pm cdt thu aug 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...

high pressure around 30.0 inches continues to track through the 
western great lakes region this afternoon. as the high pressure 
exits to the southeast later tonight, south to southwest winds 
will develop. theses winds will increase for friday, along with 
shower and thunderstorm chances, as low pressure around 29.8 
inches moves across the region and drags a cold front through lake
michigan. gusty winds will then shift to the northwest later 
friday night into saturday after the front exits. another high 
pressure system around 30.2 inches is expected to build into the 
region later this weekend, which may maintain gusty northerly 
winds as it moves in.


lmz261-362-364-366-563-565-567-868-210315-
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-
359 pm cdt thu aug 20 2026

sheboygan wi to pentwater mi north...

.tonight...south winds 10 to 20 kt. waves 1 to 3 ft. 
.friday...south winds 10 to 20 kt increasing to 30 kt. chance of
showers in the morning, then chance of showers and slight chance
of thunderstorms in the afternoon. waves 3 to 5 ft building to
4 to 6 ft occasionally to 8 ft. 
.friday night...south winds 10 to 20 kt veering to northwest.
chance of showers. waves 4 to 6 ft occasionally to 8 ft subsiding
to 2 to 4 ft. 
.saturday...northwest winds 15 to 25 kt increasing to 30 kt.
chance of showers in the afternoon. waves 2 to 4 ft. 
.saturday night...north winds to 30 kt diminishing to 15 to
25 kt. waves 4 to 6 ft occasionally to 8 ft. 
.sunday...north winds to 30 kt. waves 4 to 6 ft occasionally to
8 ft. 
.sunday night...north gales to 35 kt diminishing to 10 to 20 kt.
waves 3 to 5 ft subsiding to 2 to 4 ft. 
.monday...northwest winds 10 to 20 kt increasing to 15 to 25 kt.
waves 1 to 3 ft. 
.tuesday...southwest winds 10 to 20 kt becoming south to 30 kt.
waves 1 to 3 ft building to 3 to 5 ft.  

$$

fzus63 kmqt 202001
glfls 
expires:202608210800;;067312

open lake forecast for lake superior
national weather service marquette mi
401 pm edt thu aug 20 2026

for waters beyond 5 nautical miles of shore on lake superior.

waves are the significant wave height - the average of the
highest 1/3 of the wave spectrum. occasional wave height is the
average of the highest 1/10 of the wave spectrum.

.synopsis...

this afternoon, lake superior remains in between 30.0 inch high 
pressure over southern ontario and a 29.8 inch low pressure 
currently moving into minnesota. the aforementioned low weakens 
while moving eastward, and brings 29.9 inch troughing over the 
western half of the lake late tonight. friday into this weekend, a 
low pressure of around 29.8 inches transits across northern ontario, 
reinforcing 29.9 inch troughing over lake superior friday into 
saturday morning. this is quickly followed by 30.1 inch ridging for 
the latter part of the weekend into early next week via a 30.2 inch 
parent high from canada that drops down into the ohio river valley 
by late monday.




lsz264-210800-
lake superior from upper entrance to portage canal to manitou
island mi 5nm off shore to the us/canadian border-
401 pm edt thu aug 20 2026

.late this afternoon...southeast winds 5 to 15 knots. a chance of
showers. waves calm to 2 feet. 
.tonight...southeast winds 5 to 15 knots. a slight chance of
thunderstorms through midnight. a chance of showers. waves
building to 1 to 3 feet. 
.friday...east winds 5 to 15 knots backing north in the
afternoon, then backing northwest late. waves subsiding to calm
to 2 feet. 
.friday night...west winds 5 to 15 knots. waves calm to 2 feet. 
.saturday...northwest winds 10 to 20 knots. a slight chance of
showers through early afternoon. waves calm to 2 feet. 
.saturday night...northwest winds 10 to 20 knots veering north
after midnight. waves building to 1 to 3 feet. 
.sunday...north winds 10 to 20 knots becoming west 5 to 15 knots
by mid afternoon. waves subsiding to calm to 2 feet. 
.sunday night...northwest winds 5 to 15 knots. waves calm to
2 feet. 
.monday...northwest winds 5 to 15 knots backing south. waves calm
to 2 feet. 
.tuesday...south winds 5 to 15 knots becoming west 10 to
20 knots. a chance of showers. waves calm to 2 feet. 

$$

fzus63 kmqt 202001
glfls 
expires:202608210800;;067313

open lake forecast for lake superior
national weather service marquette mi
401 pm edt thu aug 20 2026

for waters beyond 5 nautical miles of shore on lake superior.

waves are the significant wave height - the average of the
highest 1/3 of the wave spectrum. occasional wave height is the
average of the highest 1/10 of the wave spectrum.

.synopsis...

this afternoon, lake superior remains in between 30.0 inch high 
pressure over southern ontario and a 29.8 inch low pressure 
currently moving into minnesota. the aforementioned low weakens 
while moving eastward, and brings 29.9 inch troughing over the 
western half of the lake late tonight. friday into this weekend, a 
low pressure of around 29.8 inches transits across northern ontario, 
reinforcing 29.9 inch troughing over lake superior friday into 
saturday morning. this is quickly followed by 30.1 inch ridging for 
the latter part of the weekend into early next week via a 30.2 inch 
parent high from canada that drops down into the ohio river valley 
by late monday.




lsz265-210800-
lake superior west of line from manitou island to marquette mi
beyond 5nm from shore-
401 pm edt thu aug 20 2026

.late this afternoon...east winds 15 to 25 knots. a slight chance
of showers. waves calm to 2 feet. 
.tonight...southeast winds 15 to 25 knots veering south late. a
chance of showers and a slight chance of thunderstorms. waves
building to 1 to 3 feet, then subsiding to calm to 2 feet. 
.friday...south winds 10 to 20 knots veering west in the
afternoon, then veering northwest late. a slight chance of
showers. a slight chance of thunderstorms by mid afternoon. waves
calm to 2 feet. 
.friday night...northwest winds 10 to 20 knots backing west after
midnight, then increasing to 15 to 25 knots late. waves calm to
2 feet. 
.saturday...northwest winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. a chance of showers through early
afternoon. waves building to 3 to 5 feet occasionally to 7 feet,
then subsiding to 2 to 4 feet. 
.saturday night...northwest winds 20 to 30 knots veering north
after midnight. waves building to 3 to 5 feet occasionally to
7 feet. 
.sunday...north winds 20 to 30 knots. waves building to 3 to
6 feet occasionally to 8 feet, then subsiding to 2 to 4 feet. 
.sunday night...northwest winds 10 to 20 knots. waves subsiding
to calm to 2 feet. 
.monday...northwest winds 10 to 20 knots backing south. waves
calm to 2 feet. 
.tuesday...south winds 10 to 20 knots becoming west 15 to
25 knots. a chance of showers. waves building to 1 to 3 feet. 

$$

fzus63 kmqt 202001
glfls 
expires:202608210800;;067314

open lake forecast for lake superior
national weather service marquette mi
401 pm edt thu aug 20 2026

for waters beyond 5 nautical miles of shore on lake superior.

waves are the significant wave height - the average of the
highest 1/3 of the wave spectrum. occasional wave height is the
average of the highest 1/10 of the wave spectrum.

.synopsis...

this afternoon, lake superior remains in between 30.0 inch high 
pressure over southern ontario and a 29.8 inch low pressure 
currently moving into minnesota. the aforementioned low weakens 
while moving eastward, and brings 29.9 inch troughing over the 
western half of the lake late tonight. friday into this weekend, a 
low pressure of around 29.8 inches transits across northern ontario, 
reinforcing 29.9 inch troughing over lake superior friday into 
saturday morning. this is quickly followed by 30.1 inch ridging for 
the latter part of the weekend into early next week via a 30.2 inch 
parent high from canada that drops down into the ohio river valley 
by late monday.




lsz266-210800-
lake superior east of a line from manitou island to marquette mi
and west of a line from grand marais mi to the us/canadian border
beyond 5nm from shore-
401 pm edt thu aug 20 2026

.late this afternoon...east winds 5 to 15 knots. a slight chance
of showers. waves calm to 2 feet. 
.tonight...southeast winds 10 to 20 knots increasing to 15 to
25 knots after midnight, then becoming south 10 to 20 knots late.
a chance of showers. a slight chance of thunderstorms after
midnight. waves building to 1 to 3 feet. 
.friday...south winds 10 to 20 knots becoming northwest 5 to
15 knots late. a chance of showers. a slight chance of
thunderstorms by mid afternoon. waves subsiding to calm to
2 feet. 
.friday night...northwest winds 5 to 15 knots increasing to 10 to
20 knots after midnight. a slight chance of showers through
midnight. waves calm to 2 feet. 
.saturday...northwest winds 20 to 30 knots. a slight chance of
showers through early afternoon. waves building to 3 to 6 feet
occasionally to 8 feet. 
.saturday night...northwest winds 20 to 30 knots veering north
after midnight. waves building to 3 to 6 feet occasionally to
8 feet. 
.sunday...north winds 20 to 30 knots backing northwest by mid
afternoon. waves building to 4 to 7 feet occasionally to 9 feet,
then subsiding to 3 to 5 feet occasionally to 7 feet. 
.sunday night...northwest winds 15 to 25 knots diminishing to
5 to 15 knots after midnight. waves subsiding to calm to 2 feet. 
.monday...northwest winds 5 to 15 knots backing south. waves calm
to 2 feet. 
.tuesday...south winds 10 to 20 knots increasing to 15 to
25 knots. a chance of showers. waves building to 1 to 3 feet. 

$$

fzus63 kmqt 202001
glfls 
expires:202608210800;;067315

open lake forecast for lake superior
national weather service marquette mi
401 pm edt thu aug 20 2026

for waters beyond 5 nautical miles of shore on lake superior.

waves are the significant wave height - the average of the
highest 1/3 of the wave spectrum. occasional wave height is the
average of the highest 1/10 of the wave spectrum.

.synopsis...

this afternoon, lake superior remains in between 30.0 inch high 
pressure over southern ontario and a 29.8 inch low pressure 
currently moving into minnesota. the aforementioned low weakens 
while moving eastward, and brings 29.9 inch troughing over the 
western half of the lake late tonight. friday into this weekend, a 
low pressure of around 29.8 inches transits across northern ontario, 
reinforcing 29.9 inch troughing over lake superior friday into 
saturday morning. this is quickly followed by 30.1 inch ridging for 
the latter part of the weekend into early next week via a 30.2 inch 
parent high from canada that drops down into the ohio river valley 
by late monday.




lsz267-210800-
lake superior from grand marais mi to whitefish point mi 5nm off
shore to the us/canadian border-
401 pm edt thu aug 20 2026

.late this afternoon...southeast winds 5 to 15 knots. waves calm
to 2 feet. 
.tonight...southeast winds 5 to 15 knots increasing to 10 to
20 knots after midnight, then veering south late. a chance of
showers. a slight chance of thunderstorms after midnight. waves
building to 1 to 3 feet. 
.friday...south winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon. a chance of showers and a slight
chance of thunderstorms. waves subsiding to calm to 2 feet. 
.friday night...west winds 10 to 20 knots veering northwest after
midnight. a slight chance of thunderstorms through midnight. a
chance of showers. waves calm to 2 feet. 
.saturday...northwest winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. waves building to 2 to 4 feet. 
.saturday night...northwest winds 20 to 30 knots veering north
after midnight. waves building to 3 to 5 feet occasionally to
7 feet. 
.sunday...north winds 20 to 30 knots backing northwest by mid
afternoon. waves building to 3 to 6 feet occasionally to 8 feet. 
.sunday night...northwest winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. waves subsiding to calm to 2 feet.
.monday...northwest winds 10 to 20 knots becoming west 5 to
15 knots. waves calm to 2 feet. 
.tuesday...south winds 10 to 20 knots. a chance of showers. waves
building to 1 to 3 feet. 

$$

fzus63 kmqt 202001
glfls 
expires:202608210800;;067310

open lake forecast for lake superior
national weather service marquette mi
401 pm edt thu aug 20 2026

for waters beyond 5 nautical miles of shore on lake superior.

waves are the significant wave height - the average of the
highest 1/3 of the wave spectrum. occasional wave height is the
average of the highest 1/10 of the wave spectrum.

.synopsis...

this afternoon, lake superior remains in between 30.0 inch high 
pressure over southern ontario and a 29.8 inch low pressure 
currently moving into minnesota. the aforementioned low weakens 
while moving eastward, and brings 29.9 inch troughing over the 
western half of the lake late tonight. friday into this weekend, a 
low pressure of around 29.8 inches transits across northern ontario, 
reinforcing 29.9 inch troughing over lake superior friday into 
saturday morning. this is quickly followed by 30.1 inch ridging for 
the latter part of the weekend into early next week via a 30.2 inch 
parent high from canada that drops down into the ohio river valley 
by late monday.




lsz162-210800-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
401 pm edt thu aug 20 2026 /301 pm cdt thu aug 20 2026/

.late this afternoon...east winds 10 to 20 knots. a chance of
showers and thunderstorms. waves calm to 2 feet. 
.tonight...east winds 5 to 15 knots backing northeast after
midnight. a chance of showers and thunderstorms through midnight.
waves calm to 2 feet. 
.friday...north winds 5 to 15 knots backing southwest in the
afternoon. waves calm to 2 feet. 
.friday night...southwest winds 5 to 15 knots veering west after
midnight, then becoming northwest 10 to 20 knots late. waves calm
to 2 feet. 
.saturday...northwest winds 10 to 20 knots becoming west 5 to
15 knots by mid afternoon. waves calm to 2 feet. 
.saturday night...north winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. waves calm to 2 feet. 
.sunday...north winds 5 to 15 knots veering south by mid
afternoon. waves calm to 2 feet. 
.sunday night...south winds 5 to 15 knots becoming north less
than 10 knots after midnight. waves calm to 2 feet. 
.monday...east winds 5 to 15 knots veering south. waves calm to
2 feet. 
.tuesday...southwest winds 5 to 15 knots becoming northwest 10 to
20 knots. a chance of showers and thunderstorms. waves calm to
2 feet. 

$$

fzus63 kmqt 202001
glfls 
expires:202608210800;;067311

open lake forecast for lake superior
national weather service marquette mi
401 pm edt thu aug 20 2026

for waters beyond 5 nautical miles of shore on lake superior.

waves are the significant wave height - the average of the
highest 1/3 of the wave spectrum. occasional wave height is the
average of the highest 1/10 of the wave spectrum.

.synopsis...

this afternoon, lake superior remains in between 30.0 inch high 
pressure over southern ontario and a 29.8 inch low pressure 
currently moving into minnesota. the aforementioned low weakens 
while moving eastward, and brings 29.9 inch troughing over the 
western half of the lake late tonight. friday into this weekend, a 
low pressure of around 29.8 inches transits across northern ontario, 
reinforcing 29.9 inch troughing over lake superior friday into 
saturday morning. this is quickly followed by 30.1 inch ridging for 
the latter part of the weekend into early next week via a 30.2 inch 
parent high from canada that drops down into the ohio river valley 
by late monday.




lsz263-210800-
lake superior from saxon harbor wi to upper entrance to portage
canal mi 5nm off shore to the us/canadian border including isle
royale national park-
401 pm edt thu aug 20 2026

.late this afternoon...east winds 5 to 15 knots. showers likely
and a slight chance of thunderstorms. waves calm to 2 feet. 
.tonight...east winds 5 to 15 knots veering southeast after
midnight, then backing northeast late. a slight chance of
thunderstorms through midnight. a chance of showers. waves calm
to 2 feet. 
.friday...northeast winds 5 to 15 knots backing north in the
afternoon, then backing west late. a slight chance of showers
through early afternoon. waves calm to 2 feet. 
.friday night...southwest winds 5 to 15 knots veering west after
midnight, then becoming northwest 10 to 20 knots late. a slight
chance of showers after midnight. waves calm to 2 feet. 
.saturday...northwest winds 10 to 20 knots becoming west 5 to
15 knots by mid afternoon. a slight chance of showers. waves calm
to 2 feet. 
.saturday night...north winds 10 to 20 knots. waves calm to
2 feet. 
.sunday...north winds 10 to 20 knots becoming southwest 5 to
15 knots by mid afternoon. waves calm to 2 feet. 
.sunday night...southwest winds 5 to 15 knots becoming south less
than 10 knots after midnight. waves calm to 2 feet. 
.monday...south winds 5 to 15 knots. waves calm to 2 feet. 
.tuesday...southwest winds 10 to 20 knots becoming west 15 to
25 knots. a chance of showers. waves building to 1 to 3 feet. 

$$