fzus61 kbuf 211409
glflo 
expires:202604212100;;747253

open lake forecast for lake ontario
national weather service buffalo ny
1008 am edt tue apr 21 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 30.4 inch high across the great lakes will slide off 
the mid-atlantic coast today. a 29.4 inch low over lower hudson bay 
this afternoon will weaken to 29.9 inches by wednesday, while 
pushing a cold front across the lake tonight. a 30.2 inch high will 
then build across the great lakes region wednesday and thursday. a 
warm front will approach the lake by friday. a 29.6 inch low may 
move southwest of the lake on saturday.


loz063>065-212100-
lake ontario open waters from hamlin beach to the saint lawrence
river-
1008 am edt tue apr 21 2026

.this afternoon...south winds 10 to 15 knots becoming southeast
15 to 20 knots. waves 1 to 3 feet. 
.tonight...southeast winds 15 to 25 knots becoming south. a
chance of showers from late evening on. waves 1 to 3 feet
building to 3 to 5 feet, then subsiding to 2 to 4 feet. 
.wednesday...east winds 10 knots or less becoming north. waves
2 feet or less. 
.wednesday night...northwest winds less than 10 knots. waves
1 foot or less. 
.thursday...northwest winds 10 knots or less becoming northeast.
waves 1 foot or less. 
.friday...northeast winds 5 to 15 knots becoming east 15 to
20 knots. a chance of rain showers friday night. waves 2 feet or
less building to 2 to 4 feet. 
.saturday...east winds 15 to 20 knots. showers likely. waves 3 to
5 feet subsiding to 2 to 4 feet. 

$$

fzus61 kbuf 211409
glflo 
expires:202604212100;;747252

open lake forecast for lake ontario
national weather service buffalo ny
1008 am edt tue apr 21 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 30.4 inch high across the great lakes will slide off 
the mid-atlantic coast today. a 29.4 inch low over lower hudson bay 
this afternoon will weaken to 29.9 inches by wednesday, while 
pushing a cold front across the lake tonight. a 30.2 inch high will 
then build across the great lakes region wednesday and thursday. a 
warm front will approach the lake by friday. a 29.6 inch low may 
move southwest of the lake on saturday.


loz062-212100-
lake ontario open waters from the niagara river to hamlin beach-
1008 am edt tue apr 21 2026

.this afternoon...south winds 5 to 15 knots becoming east 15 to
20 knots. waves 2 feet or less. 
.tonight...east winds 15 to 20 knots becoming northeast 5 to
15 knots. a chance of rain showers after midnight. waves 1 to
3 feet. 
.wednesday...north winds less than 10 knots. waves 2 feet or
less. 
.wednesday night...west winds less than 10 knots becoming
northwest. waves 1 foot or less. 
.thursday...north winds 10 knots or less becoming northeast.
waves 1 foot or less. 
.friday...east winds 10 to 15 knots increasing to 15 to 20 knots.
a chance of showers friday night. waves 1 to 3 feet building to
3 to 5 feet. 
.saturday...east winds 15 to 20 knots becoming northeast 10 to
15 knots. showers likely. waves 3 to 5 feet. 

$$

fzus61 kcle 211322
glfle 
expires:202604212015;;745830

open lake forecast for lake erie
national weather service cleveland oh
922 am edt tue apr 21 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...
a warm front will cross the lake today and then be pushed back
south tonight into wednesday. high pressure 30.10 inches will
build from the north on wednesday night and remain in the region
through thursday. low pressure 29.50 inches will enter the
northwest great lakes on friday and slowly move southeast,
weakening to 29.70 inches over lake erie on saturday.


lez162>164-212015-
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-
922 am edt tue apr 21 2026

.this afternoon...south winds 15 to 20 knots becoming southwest.
waves 2 to 4 feet subsiding to 1 to 3 feet. 
.tonight...southwest winds 10 to 15 knots becoming west. showers
likely with a chance of thunderstorms in the evening, then a
chance of showers with a slight chance of thunderstorms after
midnight. waves 1 to 2 feet. 
.wednesday...north winds 10 knots or less becoming east. waves
1 foot or less. 
.wednesday night...east winds 10 knots or less becoming
southeast. waves 1 foot or less. 
.thursday...southeast winds 5 to 10 knots. waves 1 foot or less. 
.friday...southeast winds 10 to 15 knots becoming north. a chance
of showers during the day, then showers likely friday night.
waves 2 feet or less. 
.saturday...north winds 10 to 15 knots becoming northeast. a
chance of showers during the day. waves 2 feet or less. 

winds and waves higher in and near thunderstorms.

$$

fzus61 kcle 211322
glfle 
expires:202604212015;;745831

open lake forecast for lake erie
national weather service cleveland oh
922 am edt tue apr 21 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...
a warm front will cross the lake today and then be pushed back
south tonight into wednesday. high pressure 30.10 inches will
build from the north on wednesday night and remain in the region
through thursday. low pressure 29.50 inches will enter the
northwest great lakes on friday and slowly move southeast,
weakening to 29.70 inches over lake erie on saturday.


lez061-165>169-212015-
ripley to buffalo ny extending from 5nm off shoreline to us-
canadian border-
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-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-
922 am edt tue apr 21 2026

.this afternoon...south winds 15 to 20 knots. waves 2 to 4 feet. 
.tonight...south winds 10 to 15 knots becoming west. a slight
chance of showers early, then a chance of showers with a slight
chance of thunderstorms. a slight chance of showers late. waves
1 to 3 feet building to 2 to 4 feet, then subsiding to 1 to
3 feet. 
.wednesday...northwest winds 10 knots or less becoming west.
waves 2 feet or less. 
.wednesday night...southwest winds less than 10 knots becoming
south. waves 1 foot or less. 
.thursday...east winds 10 knots or less. waves 1 foot or less. 
.friday...east winds 5 to 15 knots becoming northeast. showers
likely friday night. waves 2 feet or less. 
.saturday...northeast winds 5 to 15 knots. a chance of showers
during the day. waves 2 feet or less. 

winds and waves higher in and near thunderstorms.

$$

fzus63 kdtx 211345
glfsc 
expires:202604212145;;746440

lake st clair forecast
national weather service detroit/pontiac mi
945 am edt tue apr 21 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...a weak low pressure system will pass through southeast
michigan this afternoon and evening. there is a chance of showers
and storms across the south and is followed by an area of high
pressure at 30.00 inches on wednesday. a warm front slowly lifts
into the area late thursday into friday as the parent low
pressure stalls over the upper midwest.


lcz460-212145-
lake st clair-
945 am edt tue apr 21 2026

.rest of today...south winds 15 to 20 knots. partly sunny. a chance
of sprinkles late in the morning. waves 1 to 3 feet.
.tonight...southwest winds 10 to 15 knots becoming west 5 to 10
knots by midnight...then veering to the north early in the morning.
partly cloudy. waves 2 feet or less.
.wednesday...north winds 5 to 10 knots until late afternoon becoming
light and variable. mostly sunny. waves 2 feet or less.
.wednesday night...northeast winds 5 to 10 knots becoming light and
variable. mostly clear. waves 2 feet or less.
.thursday...southeast winds 5 to 10 knots. mostly clear. waves 2
feet or less.
.friday...southeast winds 10 to 15 knots. partly cloudy. light
showers likely. waves 2 feet or less.
.saturday...northeast winds 10 to 15 knots. mostly cloudy. light
showers likely. waves 2 feet or less.

$$

fzus63 kdtx 211345
glflh 
expires:202604212145;;746438

open lake forecast for lake huron
national weather service detroit/pontiac mi
945 am edt tue apr 21 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...a weak low pressure system will pass through southeast
michigan this afternoon and evening. there is a chance of showers
and storms across the south and is followed by an area of high
pressure at 30.00 inches on wednesday. a warm front slowly lifts
into the area late thursday into friday as the parent low
pressure stalls over the upper midwest.


lhz462>464-212145-
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-
945 am edt tue apr 21 2026

.rest of today...south winds 15 to 20 knots decreasing to 10 to
15 knots late in the afternoon. sprinkles. waves 4 to 6 feet. 
.tonight...south winds 5 to 10 knots. waves 2 to 4 feet subsiding
to 1 to 3 feet in the late evening and overnight. waves
occasionally around 8 feet. 
.wednesday...north winds 5 to 10 knots. waves 2 feet or less. 
.wednesday night...north winds 5 to 10 knots early in the evening
becoming light and variable. waves 2 feet or less. 
.thursday...southeast winds 5 to 10 knots becoming east 10 to
15 knots late in the afternoon. waves 2 feet or less. 
.friday...southeast winds 10 to 15 knots. showers likely . waves
1 to 3 feet building to 2 to 4 feet . 
.saturday...east winds 10 to 15 knots backing to the northeast in
the late morning and early afternoon...then becoming north 5 to
10 knots . showers likely early in the morning...then a chance of
showers in the late morning and early afternoon. waves 2 to
4 feet. 


$$

fzus63 kdtx 211345
glflh 
expires:202604212145;;746437

open lake forecast for lake huron
national weather service detroit/pontiac mi
945 am edt tue apr 21 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...a weak low pressure system will pass through southeast
michigan this afternoon and evening. there is a chance of showers
and storms across the south and is followed by an area of high
pressure at 30.00 inches on wednesday. a warm front slowly lifts
into the area late thursday into friday as the parent low
pressure stalls over the upper midwest.


lhz361>363-212145-
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-
945 am edt tue apr 21 2026

.rest of today...south winds 15 to 20 knots decreasing to 10 to
15 knots in the afternoon. waves 5 to 7 feet. waves occasionally
around 10 feet. 
.tonight...north winds 5 to 10 knots. waves 3 to 5 feet subsiding
to 1 to 3 feet after midnight. 
.wednesday...north winds 5 to 10 knots until late afternoon
becoming light and variable. waves 2 feet or less. 
.wednesday night...light and variable winds. waves 2 feet or
less. 
.thursday...east winds 5 to 10 knots increasing to 10 to
15 knots. waves 1 to 3 feet building to 3 to 5 feet. 
.friday...east winds 15 to 20 knots. showers likely . waves 5 to
7 feet. waves occasionally around 10 feet. 
.saturday...northeast winds 15 to 20 knots becoming north 10 to
15 knots. a chance of showers until afternoon. waves 4 to 6 feet.
waves occasionally around 8 feet. 


$$

fzus63 kmkx 211410
glflm 
expires:202604212130;;747536

open lake forecast for lake michigan
national weather service milwaukee/sullivan wi
910 am cdt tue apr 21 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 30.4 inches over the far eastern united
states and an approaching weak cold front over northwest wisconsin
and southeast minnesota, will support breezy south to southwest
winds over southern lake michigan into the early afternoon. the
winds will then diminish and gradually become light north to
northeasterly tonight, as high pressure moves across ontario and
the northern great lakes.

the high over the northern great lakes will then shift to the
lower great lakes on wednesday. light northeast to east winds on
wednesday will then become southeast wednesday night and increase
thursday into friday, as strong low pressure around 29.2 inches 
develops in the northern plains.


lmz080-669-671-673-675-777-779-870-872-874-876-878-212130-
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-
910 am cdt tue apr 21 2026

sheboygan wi to pentwater mi south...

.rest of today...south to southwest winds 20 to 25 kt diminishing
to 10 to 20 kt. chance of rain showers and slight chance of 
thunderstorms this afternoon. waves 4 to 7 ft occasionally to 9 ft
subsiding to 3 to 5 ft. 
.tonight...variable winds 5 to 10 kt becoming north. patchy fog 
overnight. waves 2 to 4 ft subsiding to 1 to 3 ft. 
.wednesday...northeast winds 5 to 10 kt. patchy fog. waves 1 to
2 ft. 
.wednesday night...southeast winds 5 to 10 kt becoming south
10 to 15 kt. waves 1 ft or less building to 1 to 3 ft. 
.thursday...south winds 10 to 20 kt. waves 2 to 4 ft building to
4 to 6 ft occasionally to 8 ft. 
.thursday night...south winds 15 to 25 kt. chance of showers.
waves 4 to 7 ft occasionally to 9 ft. 
.friday...south winds 15 to 25 kt diminishing to 10 to 20 kt.
rain showers likely. waves 4 to 7 ft occasionally to 9 ft. 
.saturday...north winds 10 to 20 kt. waves 3 to 5 ft.  

$$

fzus63 kmkx 211410
glflm 
expires:202604212130;;747535

open lake forecast for lake michigan
national weather service milwaukee/sullivan wi
910 am cdt tue apr 21 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 30.4 inches over the far eastern united
states and an approaching weak cold front over northwest wisconsin
and southeast minnesota, will support breezy south to southwest
winds over southern lake michigan into the early afternoon. the
winds will then diminish and gradually become light north to
northeasterly tonight, as high pressure moves across ontario and
the northern great lakes.

the high over the northern great lakes will then shift to the
lower great lakes on wednesday. light northeast to east winds on
wednesday will then become southeast wednesday night and increase
thursday into friday, as strong low pressure around 29.2 inches 
develops in the northern plains.


lmz261-362-364-366-563-565-567-868-212130-
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-
910 am cdt tue apr 21 2026

sheboygan wi to pentwater mi north...

.rest of today...south winds 15 to 20 kt becoming southwest 10 to
15 kt. waves 4 to 6 ft occasionally to 8 ft subsiding to 3 to 5 
ft. 
.tonight...north winds 5 to 10 kt increasing to 10 to 15 kt.
waves 2 to 4 ft subsiding to 1 to 3 ft. 
.wednesday...northeast winds 5 to 10 kt becoming east. waves 1 to
2 ft. 
.wednesday night...east winds 5 to 10 kt becoming southeast 10 to
15 kt. waves 1 ft or less building to 1 to 2 ft. 
.thursday...southeast winds 10 to 20 kt. waves 2 to 4 ft building
to 4 to 6 ft occasionally to 8 ft. 
.thursday night...southeast winds 15 to 25 kt increasing to
30 kt. chance of rain showers. waves 4 to 7 ft occasionally to
9 ft. 
.friday...south winds 15 to 25 kt diminishing to 10 to 20 kt.
rain showers likely. waves 4 to 7 ft occasionally to 9 ft. 
.saturday...north winds 10 to 20 kt becoming northeast. waves
3 to 5 ft.  

$$

fzus63 kmqt 211401
glfls 
expires:202604212000;;746956

open lake forecast for lake superior
national weather service marquette mi
1000 am edt tue apr 21 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...

a 29.8 inch trough continues across lake superior this morning. 
behind it, 30.0 inch high pressure ridging returns over the lake by 
this evening. a 29.2 inch low then develops over the northern 
rockies on wednesday and tracks into manitoba by no later than 
thursday evening. this sends 29.6 to 29.7 inch troughing over lake 
superior thursday night into friday. 30.1 inch ridging slowly 
returns to lake superior on saturday.



lsz266-212000-
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-
1000 am edt tue apr 21 2026

.rest of today...northwest winds 10 to 20 knots diminishing to
5 to 15 knots late. waves 2 to 4 feet subsiding to calm to
2 feet. 
.tonight...northwest winds 5 to 15 knots veering north late.
waves calm to 2 feet. 
.wednesday...south winds 5 to 15 knots backing southeast in the
afternoon, then becoming east 10 to 20 knots late. waves calm to
2 feet. 
.wednesday night...southeast winds 10 to 20 knots increasing to
15 to 25 knots after midnight. waves building to 3 to 5 feet
occasionally to 7 feet. 
.thursday...southeast winds 20 to 30 knots increasing to gales to
35 knots by mid afternoon. waves building to 5 to 8 feet
occasionally to 10 feet. 
.thursday night...southeast gales to 40 knots. a chance of rain
showers. waves building to 7 to 10 feet occasionally to 13 feet. 
.friday...southeast gales to 40 knots becoming northwest 15 to
25 knots. rain showers likely, then a chance of rain showers.
waves subsiding to 3 to 6 feet occasionally to 8 feet. 
.saturday...northwest winds 10 to 20 knots backing southwest.
waves subsiding to calm to 2 feet, then building to 2 to 4 feet. 

$$

fzus63 kmqt 211401
glfls 
expires:202604212000;;746957

open lake forecast for lake superior
national weather service marquette mi
1000 am edt tue apr 21 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...

a 29.8 inch trough continues across lake superior this morning. 
behind it, 30.0 inch high pressure ridging returns over the lake by 
this evening. a 29.2 inch low then develops over the northern 
rockies on wednesday and tracks into manitoba by no later than 
thursday evening. this sends 29.6 to 29.7 inch troughing over lake 
superior thursday night into friday. 30.1 inch ridging slowly 
returns to lake superior on saturday.



lsz267-212000-
lake superior from grand marais mi to whitefish point mi 5nm off
shore to the us/canadian border-
1000 am edt tue apr 21 2026

.rest of today...west winds 10 to 20 knots veering northwest
late. waves 2 to 4 feet subsiding to calm to 2 feet. 
.tonight...northwest winds 5 to 15 knots veering north late.
waves calm to 2 feet. 
.wednesday...southeast winds 5 to 15 knots backing east late.
waves calm to 2 feet. 
.wednesday night...east winds 5 to 15 knots becoming southeast
10 to 20 knots after midnight. waves building to 1 to 3 feet. 
.thursday...southeast winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. waves building to 3 to 6 feet
occasionally to 8 feet. 
.thursday night...southeast winds 20 to 30 knots increasing to
gales to 35 knots after midnight. waves building to 4 to 7 feet
occasionally to 9 feet. 
.friday...southeast gales to 35 knots diminishing to 15 to
25 knots. a chance of rain showers. waves building to 5 to 8 feet
occasionally to 10 feet, then subsiding to 2 to 4 feet. 
.saturday...northwest winds 10 to 20 knots becoming north 5 to
15 knots. waves subsiding to calm to 2 feet, then building to
1 to 3 feet. 

$$

fzus63 kmqt 211401
glfls 
expires:202604212000;;746952

open lake forecast for lake superior
national weather service marquette mi
1000 am edt tue apr 21 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...

a 29.8 inch trough continues across lake superior this morning. 
behind it, 30.0 inch high pressure ridging returns over the lake by 
this evening. a 29.2 inch low then develops over the northern 
rockies on wednesday and tracks into manitoba by no later than 
thursday evening. this sends 29.6 to 29.7 inch troughing over lake 
superior thursday night into friday. 30.1 inch ridging slowly 
returns to lake superior on saturday.



lsz162-212000-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
1000 am edt tue apr 21 2026 /900 am cdt tue apr 21 2026/

.rest of today...northwest winds 5 to 15 knots backing southwest
in the afternoon, then backing south late. waves calm to 2 feet. 
.tonight...southeast winds less than 10 knots backing east after
midnight, then increasing to 5 to 15 knots late. waves calm to
2 feet. 
.wednesday...east winds 5 to 15 knots becoming northeast 10 to
20 knots late. waves calm to 2 feet. 
.wednesday night...northeast winds 10 to 20 knots veering east
after midnight. a slight chance of thunderstorms through
midnight. a slight chance of rain showers. waves building to 2 to
4 feet. 
.thursday...east winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. a chance of rain showers and a slight
chance of thunderstorms by mid afternoon. waves building to 3 to
6 feet occasionally to 8 feet. 
.thursday night...east winds 10 to 20 knots increasing to 15 to
25 knots after midnight. rain showers and a chance of
thunderstorms. waves building to 4 to 7 feet occasionally to
9 feet, then subsiding to 3 to 6 feet occasionally to 8 feet. 
.friday...north winds 15 to 25 knots becoming northwest 10 to
20 knots. a chance of rain showers. waves subsiding to 1 to
3 feet. 
.saturday...west winds 10 to 20 knots becoming north 5 to
15 knots. waves subsiding to calm to 2 feet. 

$$

fzus63 kmqt 211401
glfls 
expires:202604212000;;746953

open lake forecast for lake superior
national weather service marquette mi
1000 am edt tue apr 21 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...

a 29.8 inch trough continues across lake superior this morning. 
behind it, 30.0 inch high pressure ridging returns over the lake by 
this evening. a 29.2 inch low then develops over the northern 
rockies on wednesday and tracks into manitoba by no later than 
thursday evening. this sends 29.6 to 29.7 inch troughing over lake 
superior thursday night into friday. 30.1 inch ridging slowly 
returns to lake superior on saturday.



lsz263-212000-
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-
1000 am edt tue apr 21 2026

.rest of today...northwest winds 5 to 15 knots becoming west less
than 10 knots in the afternoon, then backing southwest late.
waves calm to 2 feet. 
.tonight...southeast winds 5 to 15 knots diminishing to less than
10 knots after midnight. waves calm to 2 feet. 
.wednesday...southeast winds less than 10 knots becoming east
5 to 15 knots in the afternoon. waves calm to 2 feet. 
.wednesday night...east winds 10 to 20 knots. a slight chance of
rain showers. waves building to 3 to 5 feet occasionally to
7 feet. 
.thursday...east winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. a slight chance of rain showers by mid
afternoon. waves building to 5 to 8 feet occasionally to 10 feet.
.thursday night...southeast winds 20 to 30 knots. rain showers
and a chance of thunderstorms. waves building to 7 to 10 feet
occasionally to 13 feet. 
.friday...southeast winds 20 to 30 knots becoming west 10 to
20 knots. rain showers likely. waves subsiding to 2 to 4 feet. 
.saturday...west winds 10 to 20 knots becoming north 5 to
15 knots. waves subsiding to calm to 2 feet. 

$$

fzus63 kmqt 211401
glfls 
expires:202604212000;;746954

open lake forecast for lake superior
national weather service marquette mi
1000 am edt tue apr 21 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...

a 29.8 inch trough continues across lake superior this morning. 
behind it, 30.0 inch high pressure ridging returns over the lake by 
this evening. a 29.2 inch low then develops over the northern 
rockies on wednesday and tracks into manitoba by no later than 
thursday evening. this sends 29.6 to 29.7 inch troughing over lake 
superior thursday night into friday. 30.1 inch ridging slowly 
returns to lake superior on saturday.



lsz264-212000-
lake superior from upper entrance to portage canal to manitou
island mi 5nm off shore to the us/canadian border-
1000 am edt tue apr 21 2026

.rest of today...northwest winds 5 to 15 knots becoming west less
than 10 knots late. waves 1 to 3 feet subsiding to calm to
2 feet. 
.tonight...southwest winds less than 10 knots backing southeast
late. waves calm to 2 feet. 
.wednesday...southeast winds less than 10 knots increasing to
5 to 15 knots in the afternoon. waves calm to 2 feet. 
.wednesday night...east winds 10 to 20 knots becoming southeast
15 to 25 knots after midnight. a slight chance of rain showers
after midnight. waves building to 3 to 5 feet occasionally to
7 feet. 
.thursday...southeast winds 20 to 30 knots backing east by mid
afternoon. waves building to 6 to 9 feet occasionally to 11 feet.
.thursday night...southeast gales to 35 knots. a chance of rain
showers through midnight. rain showers likely after midnight.
waves building to 7 to 10 feet occasionally to 13 feet. 
.friday...southeast gales to 35 knots becoming northwest 10 to
20 knots. rain showers likely, then a chance of rain showers.
waves subsiding to 3 to 5 feet occasionally to 7 feet. 
.saturday...southwest winds 10 to 20 knots becoming southeast
5 to 15 knots. waves subsiding to calm to 2 feet. 

$$

fzus63 kmqt 211401
glfls 
expires:202604212000;;746955

open lake forecast for lake superior
national weather service marquette mi
1000 am edt tue apr 21 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...

a 29.8 inch trough continues across lake superior this morning. 
behind it, 30.0 inch high pressure ridging returns over the lake by 
this evening. a 29.2 inch low then develops over the northern 
rockies on wednesday and tracks into manitoba by no later than 
thursday evening. this sends 29.6 to 29.7 inch troughing over lake 
superior thursday night into friday. 30.1 inch ridging slowly 
returns to lake superior on saturday.



lsz265-212000-
lake superior west of line from manitou island to marquette mi
beyond 5nm from shore-
1000 am edt tue apr 21 2026

.rest of today...northwest winds 10 to 20 knots veering north in
the afternoon, then diminishing to 5 to 15 knots late. waves calm
to 2 feet. 
.tonight...south winds 5 to 15 knots veering west after midnight,
then backing south late. waves calm to 2 feet. 
.wednesday...southeast winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon, then becoming east 15 to 25 knots
late. waves calm to 2 feet. 
.wednesday night...southeast winds 15 to 25 knots. waves building
to 2 to 4 feet. 
.thursday...southeast winds 20 to 30 knots increasing to gales to
35 knots by mid afternoon. waves building to 5 to 8 feet
occasionally to 10 feet. 
.thursday night...southeast gales to 35 knots. a chance of rain
showers. waves building to 6 to 9 feet occasionally to 11 feet. 
.friday...southeast gales to 35 knots becoming west 15 to
25 knots. rain showers likely, then a chance of rain showers.
waves subsiding to 2 to 4 feet. 
.saturday...west winds 10 to 20 knots backing southwest. waves
subsiding to calm to 2 feet. 

$$