(1/11)
Latest Great Lakes Marine Forecast by KDTX
Issued 7/21/2026 3:37 AM America/New_York.
Valid through 7/21/2026 11:45 AM America/New_York.
fzus63 kdtx 210737
glflh
expires:202607211545;;336683
open lake forecast for lake huron
national weather service detroit/pontiac mi
337 am edt tue jul 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 cold front tracks across the great lakes late
tonight, with potential for strong to severe thunderstorms in its
wake. a second cold front then sweeps across the area tuesday
evening, bringing a brief period of gusts to gale force. high
pressure fills in mid-week for a drier pattern to end the work
week.
lhz361-211545-
lake huron from 5nm east of mackinac bridge to presque isle lt
beyond 5 nm off shore-
337 am edt tue jul 21 2026
.today...southwest winds 10 to 15 knots becoming west 15 to
20 knots with gusts to around 30 knots in the late morning and
early afternoon...then increasing to 20 to 25 knots with gusts to
around 30 knots late in the afternoon. waves 4 to 6 feet building
to 6 to 9 feet late in the afternoon. waves occasionally around
12 feet.
.tonight...northwest winds to 30 knots with brief gusts to 35
knot gales. waves 8 to 12 feet. waves occasionally around 15 feet.
.wednesday...northwest winds 20 to 25 knots. gusts to 30 knots
early in the morning then 30 knots early in the afternoon. waves
6 to 9 feet. waves occasionally around 12 feet.
.wednesday night...northwest winds 15 to 20 knots with gusts to
around 30 knots decreasing to 10 to 15 knots in the late evening
and overnight. waves 4 to 6 feet. waves occasionally around
8 feet.
.thursday...west winds 10 to 15 knots becoming southwest 5 to
10 knots late in the afternoon. waves 1 to 3 feet.
.friday...southwest winds 10 to 15 knots decreasing to 5 to
10 knots in the late morning and early afternoon...then backing
to the south . waves 1 to 3 feet.
.saturday...southwest winds 5 to 10 knots backing to the
southeast . a chance of showers by midnight. waves 1 to 3 feet.
$$
(2/11)
Latest Great Lakes Marine Forecast by KDTX
Issued 7/21/2026 3:37 AM America/New_York.
Valid through 7/21/2026 11:45 AM America/New_York.
fzus63 kdtx 210737
glflh
expires:202607211545;;336684
open lake forecast for lake huron
national weather service detroit/pontiac mi
337 am edt tue jul 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 cold front tracks across the great lakes late
tonight, with potential for strong to severe thunderstorms in its
wake. a second cold front then sweeps across the area tuesday
evening, bringing a brief period of gusts to gale force. high
pressure fills in mid-week for a drier pattern to end the work
week.
lhz362-363-211545-
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-
337 am edt tue jul 21 2026
.today...southwest winds 10 to 15 knots becoming west 15 to
20 knots with gusts to around 30 knots late in the afternoon. a
chance of showers. waves 6 to 9 feet. waves occasionally around
12 feet.
.tonight...northwest winds to 30 knots with brief gusts to 35
knot gales. waves 10 to 14 feet. waves occasionally around 18
feet.
.wednesday...northwest winds 20 to 25 knots. gusts to 30 knots
early in the morning then 30 knots early in the afternoon. waves
8 to 12 feet. waves occasionally around 15 feet.
.wednesday night...northwest winds 15 to 20 knots with gusts to
around 30 knots decreasing to 10 to 15 knots in the late evening
and overnight. waves 5 to 7 feet. waves occasionally around
10 feet.
.thursday...west winds 5 to 10 knots backing to the south late in
the afternoon. waves 2 to 4 feet subsiding to 1 to 3 feet.
.friday...southwest winds 5 to 10 knots becoming southeast 10 to
15 knots early in the evening...then becoming south 5 to 10 knots
by midnight. waves 1 to 3 feet.
.saturday...southwest winds 5 to 10 knots becoming south 10 to
15 knots early in the evening...then decreasing to 5 to 10 knots
by midnight. a chance of showers by midnight. waves 1 to 3 feet
building to 2 to 4 feet .
$$
(3/11)
Latest Great Lakes Marine Forecast by KDTX
Issued 7/21/2026 3:37 AM America/New_York.
Valid through 7/21/2026 11:45 AM America/New_York.
fzus63 kdtx 210737
glflh
expires:202607211545;;336685
open lake forecast for lake huron
national weather service detroit/pontiac mi
337 am edt tue jul 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 cold front tracks across the great lakes late
tonight, with potential for strong to severe thunderstorms in its
wake. a second cold front then sweeps across the area tuesday
evening, bringing a brief period of gusts to gale force. high
pressure fills in mid-week for a drier pattern to end the work
week.
lhz462>464-211545-
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-
337 am edt tue jul 21 2026
.today...southwest winds 15 to 20 knots with gusts to around
30 knots becoming west 10 to 15 knots in the afternoon. a chance
of showers and thunderstorms. waves 3 to 5 feet.
.tonight...northwest winds 15 to 20 knots increasing to 20 to
25 knots with gusts to around 30 knots in the late evening and
overnight. a chance of showers and thunderstorms in the evening.
waves 6 to 9 feet. waves occasionally around 11 feet.
.wednesday...northwest winds 20 to 25 knots decreasing to 15 to
20 knots early in the afternoon. waves 8 to 12 feet. waves
occasionally around 15 feet.
.wednesday night...northwest winds 10 to 15 knots. waves 5 to
7 feet. waves occasionally around 10 feet.
.thursday...northwest winds 5 to 10 knots in the morning becoming
light and variable...then becoming south 5 to 10 knots late in
the afternoon. waves 2 to 4 feet subsiding to 2 feet or less.
.friday...southwest winds 5 to 10 knots backing to the southeast
. waves 2 feet or less.
.saturday...south winds 5 to 10 knots early in the morning
becoming light and variable...then becoming south 5 to 10 knots .
waves 2 feet or less.
$$
(4/11)
Latest Great Lakes Marine Forecast by KMKX
Issued 7/21/2026 3:02 AM US/Central.
Valid through 7/21/2026 10:30 AM US/Central.
fzus63 kmkx 210802
glflm
expires:202607211530;;337395
open lake forecast for lake michigan
national weather service milwaukee/sullivan wi
302 am cdt tue jul 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...
low pressure tracking east through ontario is dragging a cold
front across the lake early this morning. gusty south to
southwest winds ahead of the front are expected. winds will veer
northwest behind the cold front and remain gusty. winds then veer
north tonight, with a few gusts to gale force possible. winds are
expected to gradually weaken by thursday, as high pressure around
30.2 inches builds into the great lakes region.
lmz261-362-364-366-563-565-567-868-211530-
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-
302 am cdt tue jul 21 2026
sheboygan wi to pentwater mi north...
.today...west winds 15 to 25 kt becoming northwest to 30 kt from
late morning on. slight chance of showers this morning, then
slight chance of showers and thunderstorms this afternoon. waves
4 to 7 ft occasionally to 9 ft building to 6 to 9 ft occasionally
to 12 ft.
.tonight...northwest winds to 30 kt. waves 7 to 10 ft
occasionally to 13 ft subsiding to 6 to 9 ft occasionally to
12 ft.
.wednesday...north winds to 30 kt. waves 5 to 8 ft occasionally
to 10 ft subsiding to 3 to 5 ft.
.wednesday night...northwest winds 15 to 25 kt becoming west
10 to 15 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 2 to 4 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 to 30 kt becoming south. waves 2 to
4 ft.
$$
(5/11)
Latest Great Lakes Marine Forecast by KMKX
Issued 7/21/2026 3:02 AM US/Central.
Valid through 7/21/2026 10:30 AM US/Central.
fzus63 kmkx 210802
glflm
expires:202607211530;;337396
open lake forecast for lake michigan
national weather service milwaukee/sullivan wi
302 am cdt tue jul 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...
low pressure tracking east through ontario is dragging a cold
front across the lake early this morning. gusty south to
southwest winds ahead of the front are expected. winds will veer
northwest behind the cold front and remain gusty. winds then veer
north tonight, with a few gusts to gale force possible. winds are
expected to gradually weaken by thursday, as high pressure around
30.2 inches builds into the great lakes region.
lmz080-669-671-673-675-777-779-870-872-874-876-878-211530-
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-
302 am cdt tue jul 21 2026
sheboygan wi to pentwater mi south...
.today...west winds 15 to 25 kt becoming northwest to 30 kt.
waves 4 to 7 ft occasionally to 9 ft.
.tonight...north winds to 30 kt. slight chance of showers in the
evening. waves 7 to 10 ft occasionally to 13 ft building to 8 to
11 ft occasionally to 14 ft, then subsiding to 7 to 10 ft
occasionally to 13 ft.
.wednesday...north winds to 30 kt. waves 7 to 10 ft occasionally
to 13 ft subsiding to 5 to 8 ft occasionally to 10 ft.
.wednesday night...north winds 15 to 25 kt becoming northwest
5 to 10 kt overnight. waves 4 to 6 ft occasionally to 8 ft
subsiding to 2 to 4 ft.
.thursday...west winds 10 to 15 kt becoming southwest 10 to
20 kt. waves 1 to 3 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 2 ft.
.saturday...southwest winds 10 to 20 kt becoming south 15 to
25 kt. waves 1 to 2 ft building to 1 to 3 ft.
$$
(6/11)
Latest Great Lakes Marine Forecast by KMQT
Issued 7/21/2026 4:13 AM America/New_York.
Valid through 7/21/2026 4:00 PM America/New_York.
fzus63 kmqt 210813 cca
glfls
expires:202607212000;;338674
open lake forecast for lake superior...corrected
national weather service marquette mi
413 am edt tue jul 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...
as a 29.2 inch low over far northern ontario this morning moves into
northern quebec later today, troughing from the low over lake
superior is replaced by ridging descending from a 30.1 inch high
moving in from the canadian prairies into the midwest today into
wednesday. the ridging over lake superior becomes maximized at 30.1
inches over the western lake on wednesday before the high flattens
and moves east towards new england thursday into friday morning.
while ridging of around 30.0 inches looks to remain over lake
superior on thursday, a weak 29.9 to 30.0 inch low could move over
the northwestern half of the lake by thursday night into friday
morning. as a low around 29.3 inches lifts from far northern ontario
into hudson bay friday night into saturday morning, expect troughing
of around 29.8 inches to move into lake superior in response by
saturday morning. troughing of at least 29.8 inches looks to remain
over the lake for the rest of the day.
lsz162-212000-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
413 am edt tue jul 21 2026 /313 am cdt tue jul 21 2026/
.early this morning...northwest winds 20 to 30 knots. a slight
chance of showers. waves 1 to 3 feet.
.today...northwest winds 20 to 30 knots diminishing to 15 to
25 knots in the afternoon, then veering north late. waves
subsiding to calm to 2 feet.
.tonight...north winds 10 to 20 knots backing northwest after
midnight. waves calm to 2 feet.
.wednesday...northwest winds 5 to 15 knots backing southwest in
the afternoon, then increasing to 10 to 20 knots late. waves
building to 1 to 3 feet.
.wednesday night...southwest winds 10 to 20 knots becoming west
5 to 15 knots after midnight. waves subsiding to calm to 2 feet.
.thursday...southwest winds 10 to 20 knots. waves building to
1 to 3 feet.
.thursday night...southwest winds 10 to 20 knots. a chance of
showers. waves subsiding to calm to 2 feet.
.friday...southwest winds 10 to 20 knots increasing to 20 to
30 knots. a chance of showers. waves building to 1 to 3 feet,
then subsiding to calm to 2 feet.
.saturday...southwest winds 20 to 30 knots becoming north 10 to
20 knots. a chance of showers. waves subsiding to calm to 2 feet.
$$
(7/11)
Latest Great Lakes Marine Forecast by KMQT
Issued 7/21/2026 4:13 AM America/New_York.
Valid through 7/21/2026 4:00 PM America/New_York.
fzus63 kmqt 210813 cca
glfls
expires:202607212000;;338675
open lake forecast for lake superior...corrected
national weather service marquette mi
413 am edt tue jul 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...
as a 29.2 inch low over far northern ontario this morning moves into
northern quebec later today, troughing from the low over lake
superior is replaced by ridging descending from a 30.1 inch high
moving in from the canadian prairies into the midwest today into
wednesday. the ridging over lake superior becomes maximized at 30.1
inches over the western lake on wednesday before the high flattens
and moves east towards new england thursday into friday morning.
while ridging of around 30.0 inches looks to remain over lake
superior on thursday, a weak 29.9 to 30.0 inch low could move over
the northwestern half of the lake by thursday night into friday
morning. as a low around 29.3 inches lifts from far northern ontario
into hudson bay friday night into saturday morning, expect troughing
of around 29.8 inches to move into lake superior in response by
saturday morning. troughing of at least 29.8 inches looks to remain
over the lake for the rest of the day.
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-
413 am edt tue jul 21 2026
.early this morning...northwest winds 15 to 25 knots. a slight
chance of showers and thunderstorms. waves 3 to 5 feet
occasionally to 7 feet.
.today...northwest winds 15 to 25 knots veering north in the
afternoon. waves subsiding to 2 to 4 feet.
.tonight...northwest winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. waves subsiding to calm to 2 feet.
.wednesday...northwest winds 5 to 15 knots backing west in the
afternoon, then becoming southwest 10 to 20 knots late. waves
building to 1 to 3 feet.
.wednesday night...southwest winds 10 to 20 knots. waves
subsiding to calm to 2 feet, then building to 1 to 3 feet.
.thursday...southwest winds 15 to 25 knots. waves building to
2 to 4 feet.
.thursday night...southwest winds 10 to 20 knots. a chance of
showers. waves subsiding to 1 to 3 feet.
.friday...southwest winds 15 to 25 knots increasing to 20 to
30 knots. a chance of showers. waves building to 2 to 4 feet,
then subsiding to 1 to 3 feet.
.saturday...southwest winds 20 to 30 knots becoming north 10 to
20 knots. a chance of showers. waves building to 4 to 7 feet
occasionally to 9 feet, then subsiding to calm to 2 feet.
$$
(8/11)
Latest Great Lakes Marine Forecast by KMQT
Issued 7/21/2026 4:13 AM America/New_York.
Valid through 7/21/2026 4:00 PM America/New_York.
fzus63 kmqt 210813 cca
glfls
expires:202607212000;;338676
open lake forecast for lake superior...corrected
national weather service marquette mi
413 am edt tue jul 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...
as a 29.2 inch low over far northern ontario this morning moves into
northern quebec later today, troughing from the low over lake
superior is replaced by ridging descending from a 30.1 inch high
moving in from the canadian prairies into the midwest today into
wednesday. the ridging over lake superior becomes maximized at 30.1
inches over the western lake on wednesday before the high flattens
and moves east towards new england thursday into friday morning.
while ridging of around 30.0 inches looks to remain over lake
superior on thursday, a weak 29.9 to 30.0 inch low could move over
the northwestern half of the lake by thursday night into friday
morning. as a low around 29.3 inches lifts from far northern ontario
into hudson bay friday night into saturday morning, expect troughing
of around 29.8 inches to move into lake superior in response by
saturday morning. troughing of at least 29.8 inches looks to remain
over the lake for the rest of the day.
lsz264-212000-
lake superior from upper entrance to portage canal to manitou
island mi 5nm off shore to the us/canadian border-
413 am edt tue jul 21 2026
.early this morning...northwest winds 15 to 25 knots. a slight
chance of showers and thunderstorms. waves 3 to 5 feet
occasionally to 7 feet.
.today...northwest winds to 30 knots with a few gale force gusts
to 35 knots possible veering north in the afternoon, then
becoming northwest 20 to 30 knots late. waves building to 5 to
8 feet occasionally to 10 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.tonight...northwest winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. waves subsiding to 1 to 3 feet.
.wednesday...northwest winds 5 to 15 knots backing west in the
afternoon, then increasing to 10 to 20 knots late. waves
subsiding to calm to 2 feet, then building to 1 to 3 feet.
.wednesday night...west winds 10 to 20 knots. waves 1 to 3 feet.
.thursday...southwest winds 10 to 20 knots. waves building to
2 to 4 feet.
.thursday night...southwest winds 5 to 15 knots increasing to
10 to 20 knots after midnight. a chance of showers. waves
subsiding to 1 to 3 feet.
.friday...southwest winds 10 to 20 knots increasing to 20 to
30 knots. a chance of showers. waves building to 2 to 4 feet,
then subsiding to 1 to 3 feet.
.saturday...southwest winds 20 to 30 knots becoming north 10 to
20 knots. a chance of showers. waves subsiding to calm to 2 feet.
$$
(9/11)
Latest Great Lakes Marine Forecast by KMQT
Issued 7/21/2026 4:13 AM America/New_York.
Valid through 7/21/2026 4:00 PM America/New_York.
fzus63 kmqt 210813 cca
glfls
expires:202607212000;;338677
open lake forecast for lake superior...corrected
national weather service marquette mi
413 am edt tue jul 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...
as a 29.2 inch low over far northern ontario this morning moves into
northern quebec later today, troughing from the low over lake
superior is replaced by ridging descending from a 30.1 inch high
moving in from the canadian prairies into the midwest today into
wednesday. the ridging over lake superior becomes maximized at 30.1
inches over the western lake on wednesday before the high flattens
and moves east towards new england thursday into friday morning.
while ridging of around 30.0 inches looks to remain over lake
superior on thursday, a weak 29.9 to 30.0 inch low could move over
the northwestern half of the lake by thursday night into friday
morning. as a low around 29.3 inches lifts from far northern ontario
into hudson bay friday night into saturday morning, expect troughing
of around 29.8 inches to move into lake superior in response by
saturday morning. troughing of at least 29.8 inches looks to remain
over the lake for the rest of the day.
lsz265-212000-
lake superior west of line from manitou island to marquette mi
beyond 5nm from shore-
413 am edt tue jul 21 2026
...gale warning in effect from 8 am edt this morning through this
evening...
.early this morning...west winds 20 to 30 knots. a chance of
showers. waves 2 to 4 feet.
.today...northwest gales to 40 knots. a slight chance of showers
through early afternoon. waves building to 6 to 9 feet
occasionally to 11 feet.
.tonight...northwest winds 20 to 30 knots diminishing to 15 to
25 knots late. waves subsiding to 2 to 4 feet.
.wednesday...northwest winds 15 to 25 knots becoming west 10 to
20 knots late. waves subsiding to calm to 2 feet.
.wednesday night...west winds 10 to 20 knots increasing to 15 to
25 knots after midnight. waves calm to 2 feet.
.thursday...west winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. waves building to 1 to 3 feet, then
subsiding to calm to 2 feet.
.thursday night...south winds 10 to 20 knots becoming southwest
15 to 25 knots after midnight. waves building to 1 to 3 feet.
.friday...southwest winds 10 to 20 knots increasing to 15 to
25 knots. a chance of showers. waves subsiding to calm to 2 feet,
then building to 2 to 4 feet.
.saturday...southwest winds 15 to 25 knots veering northwest. a
chance of showers. waves subsiding to calm to 2 feet, then
building to 1 to 3 feet.
$$
(10/11)
Latest Great Lakes Marine Forecast by KMQT
Issued 7/21/2026 4:13 AM America/New_York.
Valid through 7/21/2026 4:00 PM America/New_York.
fzus63 kmqt 210813 cca
glfls
expires:202607212000;;338678
open lake forecast for lake superior...corrected
national weather service marquette mi
413 am edt tue jul 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...
as a 29.2 inch low over far northern ontario this morning moves into
northern quebec later today, troughing from the low over lake
superior is replaced by ridging descending from a 30.1 inch high
moving in from the canadian prairies into the midwest today into
wednesday. the ridging over lake superior becomes maximized at 30.1
inches over the western lake on wednesday before the high flattens
and moves east towards new england thursday into friday morning.
while ridging of around 30.0 inches looks to remain over lake
superior on thursday, a weak 29.9 to 30.0 inch low could move over
the northwestern half of the lake by thursday night into friday
morning. as a low around 29.3 inches lifts from far northern ontario
into hudson bay friday night into saturday morning, expect troughing
of around 29.8 inches to move into lake superior in response by
saturday morning. troughing of at least 29.8 inches looks to remain
over the lake for the rest of the day.
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-
413 am edt tue jul 21 2026
...gale warning in effect from 8 am edt this morning through this
evening...
.early this morning...west winds 20 to 30 knots. a slight chance
of showers. waves 2 to 4 feet building to 3 to 5 feet
occasionally to 7 feet.
.today...northwest gales to 40 knots. a slight chance of showers
through early afternoon. waves building to 7 to 10 feet
occasionally to 13 feet.
.tonight...northwest winds 20 to 30 knots. a slight chance of
showers through midnight. waves subsiding to 3 to 5 feet
occasionally to 7 feet.
.wednesday...northwest winds 15 to 25 knots backing west late.
waves subsiding to 2 to 4 feet.
.wednesday night...west winds 10 to 20 knots increasing to 15 to
25 knots after midnight. waves subsiding to 1 to 3 feet.
.thursday...west winds 10 to 20 knots backing southwest by mid
afternoon. waves 1 to 3 feet.
.thursday night...south winds 10 to 20 knots becoming southwest
15 to 25 knots after midnight. waves subsiding to calm to 2 feet,
then building to 1 to 3 feet.
.friday...south winds 10 to 20 knots increasing to 15 to
25 knots. waves subsiding to calm to 2 feet, then building to
3 to 5 feet occasionally to 7 feet.
.saturday...south winds 15 to 25 knots diminishing to 10 to
20 knots. a chance of showers. waves subsiding to 1 to 3 feet.
$$
(11/11)
Latest Great Lakes Marine Forecast by KMQT
Issued 7/21/2026 4:13 AM America/New_York.
Valid through 7/21/2026 4:00 PM America/New_York.
fzus63 kmqt 210813 cca
glfls
expires:202607212000;;338679
open lake forecast for lake superior...corrected
national weather service marquette mi
413 am edt tue jul 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...
as a 29.2 inch low over far northern ontario this morning moves into
northern quebec later today, troughing from the low over lake
superior is replaced by ridging descending from a 30.1 inch high
moving in from the canadian prairies into the midwest today into
wednesday. the ridging over lake superior becomes maximized at 30.1
inches over the western lake on wednesday before the high flattens
and moves east towards new england thursday into friday morning.
while ridging of around 30.0 inches looks to remain over lake
superior on thursday, a weak 29.9 to 30.0 inch low could move over
the northwestern half of the lake by thursday night into friday
morning. as a low around 29.3 inches lifts from far northern ontario
into hudson bay friday night into saturday morning, expect troughing
of around 29.8 inches to move into lake superior in response by
saturday morning. troughing of at least 29.8 inches looks to remain
over the lake for the rest of the day.
lsz267-212000-
lake superior from grand marais mi to whitefish point mi 5nm off
shore to the us/canadian border-
413 am edt tue jul 21 2026
...gale warning in effect from 8 am edt this morning through this
evening...
.early this morning...west winds 15 to 25 knots. waves 2 to
4 feet.
.today...northwest winds 20 to 30 knots increasing to gales to
35 knots in the afternoon. a slight chance of showers through
early afternoon. waves building to 6 to 10 feet occasionally to
13 feet.
.tonight...northwest winds 20 to 30 knots. a slight chance of
showers through midnight. waves subsiding to 3 to 6 feet
occasionally to 8 feet.
.wednesday...northwest winds 15 to 25 knots backing west late.
waves subsiding to 3 to 5 feet occasionally to 7 feet.
.wednesday night...west winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. waves subsiding to 1 to 3 feet.
.thursday...southwest winds 5 to 15 knots. waves subsiding to
calm to 2 feet.
.thursday night...south winds 10 to 20 knots becoming southwest
15 to 25 knots after midnight. waves building to 1 to 3 feet.
.friday...southwest winds 5 to 15 knots becoming south 15 to
25 knots. waves subsiding to calm to 2 feet, then building to
3 to 5 feet occasionally to 7 feet.
.saturday...south winds 10 to 20 knots. a chance of showers.
showers likely. waves subsiding to 1 to 3 feet.
$$
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