499
FZUS63 KMQT 211954
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
354 PM EDT Tue May 21 2024

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 29.4 inch low pressure currently over western Iowa deepens
to 29.0 inches as it lifts north-northeast, eventually tracking
over western Lake Superior into Ontario late tonight and early
Wednesday. The low continues north into Ontario during the day
Wednesday and into Wednesday night as it weakens to 29.4 inches.
29.9 inch ridging builds in Thursday across Lake Superior as the
low slowly moves east toward James Bay. This ridging shifts east
as a 29.6 inch low lifts northeast through the Northern Plains
Thursday night into Friday. Weak troughing of 29.8 inches moves
over Lake Superior by Saturday.

LSZ162-220400-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
354 PM EDT Tue May 21 2024 /254 PM CDT Tue May 21 2024/

...GALE WARNING IN EFFECT THROUGH WEDNESDAY EVENING...

.LATE THIS AFTERNOON...Northeast gales to 35 knots. Patchy dense
fog. Showers and scattered thunderstorms. Waves 5 to 8 feet
occasionally to 10 feet building to 7 to 10 feet occasionally to
13 feet.
.TONIGHT...East gales to 35 knots veering south late. Patchy fog.
Showers through midnight. A chance of thunderstorms. A chance of
showers after midnight. Waves building to 8 to 11 feet
occasionally to 14 feet, then subsiding to 5 to 8 feet
occasionally to 10 feet.
.WEDNESDAY...Southwest gales to 40 knots veering west in the
afternoon. A slight chance of thunderstorms through early
afternoon. A chance of showers. Waves building to 9 to 12 feet
occasionally to 15 feet, then subsiding to 5 to 8 feet
occasionally to 10 feet.
.WEDNESDAY NIGHT...West winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. A slight chance of rain showers through
midnight. Waves subsiding to 3 to 5 feet occasionally to 7 feet.
.THURSDAY...West winds 10 to 20 knots backing southwest by mid
afternoon. A slight chance of showers and thunderstorms by mid
afternoon. Waves subsiding to 1 to 3 feet.
.THURSDAY NIGHT...North winds 10 to 20 knots veering northeast
after midnight. A chance of rain showers. Waves subsiding to calm
to 2 feet, then building to 1 to 3 feet.
.FRIDAY...Northeast winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. A chance of rain showers through early
afternoon, then rain showers likely and a chance of thunderstorms
by mid afternoon. Waves building to 4 to 7 feet occasionally to
9 feet.
.FRIDAY NIGHT...Northeast winds 15 to 25 knots backing west after
midnight. Rain showers likely through midnight. A chance of
thunderstorms. A chance of rain showers after midnight. Waves
subsiding to 3 to 5 feet occasionally to 7 feet.
.SATURDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves subsiding to calm to 2 feet.
.SUNDAY...West winds 10 to 20 knots veering northeast. Waves calm
to 2 feet.

$$

LSZ263-220400-
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-
354 PM EDT Tue May 21 2024

...GALE WARNING IN EFFECT FROM 10 PM EDT THIS EVENING THROUGH
WEDNESDAY EVENING...

.LATE THIS AFTERNOON...East winds 20 to 30 knots. Scattered
showers and isolated thunderstorms. Waves 3 to 6 feet
occasionally to 8 feet building to 4 to 7 feet occasionally to
9 feet.
.TONIGHT...East gales to 35 knots veering southeast late. Patchy
fog. Showers through midnight. A chance of thunderstorms. A
chance of showers after midnight. Waves building to 6 to 10 feet
occasionally to 13 feet.
.WEDNESDAY...Southwest gales to 45 knots veering west late. A
slight chance of thunderstorms through early afternoon. A chance
of showers. Waves building to 11 to 15 feet occasionally to
19 feet, then subsiding to 9 to 12 feet occasionally to 15 feet.
.WEDNESDAY NIGHT...West winds 20 to 30 knots. A chance of rain
showers through midnight. Waves subsiding to 4 to 7 feet
occasionally to 9 feet.
.THURSDAY...West winds 15 to 25 knots becoming southwest 10 to
20 knots by mid afternoon. A slight chance of showers and
thunderstorms by mid afternoon. Waves subsiding to 2 to 4 feet.
.THURSDAY NIGHT...Northwest winds 5 to 15 knots veering northeast
after midnight. Waves subsiding to calm to 2 feet.
.FRIDAY...Northeast winds 10 to 20 knots becoming east 15 to
25 knots by mid afternoon. A chance of rain showers. A chance of
thunderstorms by mid afternoon. Waves building to 3 to 5 feet
occasionally to 7 feet.
.FRIDAY NIGHT...East winds 10 to 20 knots becoming west 15 to
25 knots after midnight. Rain showers likely through midnight. A
chance of thunderstorms. A chance of rain showers after midnight.
Waves 3 to 5 feet occasionally to 7 feet.
.SATURDAY...West winds 15 to 25 knots diminishing to 5 to
15 knots. A chance of rain showers. Waves subsiding to calm to
2 feet.
.SUNDAY...West winds 5 to 15 knots veering northeast. Waves calm
to 2 feet.

$$

LSZ264-220400-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
354 PM EDT Tue May 21 2024

...GALE WARNING IN EFFECT FROM 10 PM EDT THIS EVENING THROUGH
WEDNESDAY EVENING...

.LATE THIS AFTERNOON...East winds 15 to 25 knots. Patchy fog.
Numerous showers. Waves 2 to 4 feet.
.TONIGHT...East winds 20 to 30 knots increasing to gales to
35 knots after midnight, then veering southeast late. Patchy fog.
Showers through midnight. A chance of thunderstorms. A chance of
showers after midnight. Waves building to 8 to 11 feet
occasionally to 14 feet.
.WEDNESDAY...South gales to 40 knots becoming southwest gales to
45 knots in the afternoon. Patchy fog through early afternoon. A
slight chance of thunderstorms through early afternoon. A chance
of showers. Waves subsiding to 7 to 10 feet occasionally to
13 feet, then building to 11 to 15 feet occasionally to 19 feet.
.WEDNESDAY NIGHT...Southwest gales to 35 knots becoming west
20 to 30 knots after midnight. A chance of rain showers through
midnight. Waves subsiding to 5 to 8 feet occasionally to 10 feet.
.THURSDAY...West winds 15 to 25 knots becoming southwest 10 to
20 knots by mid afternoon. Waves subsiding to 2 to 4 feet.
.THURSDAY NIGHT...West winds 5 to 15 knots veering north after
midnight. Waves subsiding to calm to 2 feet.
.FRIDAY...Northeast winds 10 to 20 knots veering east by mid
afternoon. A chance of rain showers. Waves building to 1 to
3 feet.
.FRIDAY NIGHT...East winds 10 to 20 knots becoming south 15 to
25 knots after midnight. Showers likely and a chance of
thunderstorms. Waves building to 3 to 5 feet occasionally to
7 feet.
.SATURDAY...Southwest winds 15 to 25 knots becoming west 5 to
15 knots. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet, then subsiding to calm to 2 feet.
.SUNDAY...Northwest winds 5 to 15 knots veering north. Waves calm
to 2 feet.

$$

LSZ265-220400-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
354 PM EDT Tue May 21 2024

...GALE WARNING IN EFFECT FROM 2 AM EDT WEDNESDAY THROUGH
WEDNESDAY MORNING...

.LATE THIS AFTERNOON...East winds 15 to 25 knots. Scattered
showers. Waves 1 to 3 feet building to 2 to 4 feet.
.TONIGHT...East winds 20 to 30 knots becoming southeast gales to
35 knots after midnight. Patchy fog. Showers likely through
midnight. A chance of thunderstorms. A chance of showers after
midnight. Waves building to 4 to 8 feet occasionally to 10 feet.
.WEDNESDAY...Southwest winds 20 to 30 knots increasing to gales
to 35 knots in the afternoon, then veering west late. A chance of
showers by mid afternoon. Waves subsiding to 3 to 6 feet
occasionally to 8 feet.
.WEDNESDAY NIGHT...West winds 15 to 25 knots backing southwest
after midnight, then veering west late. A chance of showers
through midnight. Waves subsiding to 1 to 3 feet.
.THURSDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. A slight chance of showers and
thunderstorms by mid afternoon. Waves subsiding to calm to
2 feet.
.THURSDAY NIGHT...West winds 5 to 15 knots veering north after
midnight. Waves calm to 2 feet.
.FRIDAY...Northeast winds 5 to 15 knots becoming east 15 to
25 knots by mid afternoon. A chance of rain showers. A chance of
thunderstorms by mid afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...East winds 10 to 20 knots veering west after
midnight. Showers likely through midnight. A chance of
thunderstorms. A chance of showers after midnight. Waves building
to 1 to 3 feet.
.SATURDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves subsiding to calm to 2 feet.
.SUNDAY...West winds 10 to 20 knots becoming north 5 to 15 knots.
Waves calm to 2 feet.

$$

LSZ266-220400-
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-
354 PM EDT Tue May 21 2024

...GALE WARNING IN EFFECT FROM 2 AM EDT WEDNESDAY THROUGH
WEDNESDAY MORNING...

.LATE THIS AFTERNOON...East winds 15 to 25 knots. Scattered
showers. Waves calm to 2 feet building to 1 to 3 feet.
.TONIGHT...East winds 20 to 30 knots becoming southeast gales to
40 knots after midnight. A chance of showers and thunderstorms.
Patchy fog after midnight. Waves building to 7 to 10 feet
occasionally to 13 feet.
.WEDNESDAY...South winds 20 to 30 knots with a few gale force
gusts to 35 knots in the afternoon. A slight chance of showers.
Waves subsiding to 5 to 8 feet occasionally to 10 feet, then
building to 10 to 14 feet occasionally to 18 feet.
.WEDNESDAY NIGHT...Southwest winds 20 to 30 knots. A chance of
rain showers through midnight. Waves subsiding to 5 to 8 feet
occasionally to 10 feet.
.THURSDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. A slight chance of showers and
thunderstorms by mid afternoon. Waves subsiding to 2 to 4 feet.
.THURSDAY NIGHT...West winds 5 to 15 knots veering north after
midnight. Waves subsiding to calm to 2 feet.
.FRIDAY...Northeast winds 5 to 15 knots becoming east 10 to
20 knots by mid afternoon. A chance of rain showers by mid
afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...East winds 10 to 20 knots veering southeast after
midnight. Showers likely and a chance of thunderstorms. Waves
building to 2 to 4 feet.
.SATURDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of rain showers. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 1 to 3 feet.
.SUNDAY...Northwest winds 10 to 20 knots becoming north 5 to
15 knots. Waves subsiding to calm to 2 feet.

$$

LSZ267-220400-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
354 PM EDT Tue May 21 2024

...GALE WARNING IN EFFECT FROM 2 AM EDT WEDNESDAY THROUGH
WEDNESDAY MORNING...

.LATE THIS AFTERNOON...East winds 10 to 20 knots. Isolated
showers. Waves calm to 2 feet.
.TONIGHT...East winds 15 to 25 knots becoming southeast 20 to
30 knots after midnight, then increasing to gales to 35 knots
late. A chance of showers and thunderstorms. Waves building to
5 to 8 feet occasionally to 10 feet.
.WEDNESDAY...South winds 20 to 30 knots diminishing to 15 to
25 knots in the afternoon, then veering southwest late. A slight
chance of showers. Waves subsiding to 1 to 3 feet.
.WEDNESDAY NIGHT...Southwest winds 10 to 20 knots increasing to
15 to 25 knots late. A chance of showers through midnight. Waves
building to 3 to 6 feet occasionally to 8 feet.
.THURSDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. A slight chance of showers and
thunderstorms by mid afternoon. Waves subsiding to 1 to 3 feet.
.THURSDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. Waves subsiding to calm to 2 feet.
.FRIDAY...North winds 10 to 20 knots veering northeast by mid
afternoon. A chance of showers by mid afternoon. Waves calm to
2 feet.
.FRIDAY NIGHT...East winds 10 to 20 knots becoming southeast
15 to 25 knots after midnight. A chance of showers through
midnight. A chance of thunderstorms. Showers likely after
midnight. Waves building to 2 to 4 feet.
.SATURDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of rain showers. Waves subsiding to calm to
2 feet.
.SUNDAY...West winds 10 to 20 knots veering north. Waves calm to
2 feet.

$$

LSZ261-220400-
MAFOR 2121/
Superior West...GALE WARNING IN EFFECT...11256 19259 12256 11340
11450 12550 11650. Waves 5 to 7 feet building to 7 to 11 feet,
then subsiding to 5 to 8 feet tonight. Waves 5 to 8 feet building
to 8 to 12 feet Wednesday.

Superior North Central...GALE WARNING IN EFFECT...11236 11240
11256 12350 11450 12560. A chance of thunderstorms tonight. Waves
1 to 2 feet building to 7 to 10 feet tonight, then building to 10
to 15 feet Wednesday.

Superior South Central...GALE WARNING IN EFFECT...11230 19236
11230 11346 12350 11440 11530 11540. A chance of thunderstorms
tonight. Waves 1 to 2 feet building to 5 to 7 feet tonight then subsiding
to 3 to 6 feet Wednesday.

Superior East...GALE WARNING IN EFFECT...11220 11230 11340 11356
11350 12440 11530. A chance of thunderstorms overnight. Waves 1
to 3 feet building to 5 to 8 feet tonight before subsiding to 3
to 5 feet Wednesday.

$$

BW

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

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