Great Lakes Forecast
Issued by NWS

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217
FZUS63 KMQT 010159
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
959 PM EDT Tue Apr 30 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...Weak 29.9 inch ridging over the east end of Lake
Superior will be forced east tonight as a 29.6 inch low pressure
over west-central Minnesota tracks northeast toward western Lake
Superior. This low pressure weakens to 29.7 inches as it tracks
east across the lake to northeastern Ontario by Wednesday evening.
Ridging builds to 30.1 inches over the Upper Great Lakes
Wednesday night, shifting east to the Lower Great Lakes and
southern Ontario on Thursday. This shift precedes a 29.6 inch low
pressure tracking across the Upper Mississippi Valley Thursday
night. The low then lifts into northwestern Ontario on Friday. A
weak 29.9 inch trough pivots across the lake on Saturday ahead of
ridging that builds to 30.0 inches over the Great Lakes Basin on
Sunday.

LSZ162-011000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
959 PM EDT Tue Apr 30 2024 /859 PM CDT Tue Apr 30 2024/

.REST OF TONIGHT...East winds 10 to 20 knots increasing to 20 to
30 knots after midnight, then backing northeast late. A chance of
rain showers by late evening, then rain showers after midnight.
Waves calm to 2 feet building to 4 to 7 feet occasionally to
9 feet, then subsiding to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY...Northeast winds 15 to 25 knots backing west in the
afternoon, then diminishing to 10 to 20 knots late. Patchy fog
through early afternoon. A chance of rain showers. Waves building
to 5 to 8 feet occasionally to 10 feet, then subsiding to 2 to
4 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots veering northwest
after midnight, then veering east late. Waves subsiding to calm
to 2 feet.
.THURSDAY...Northeast winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. A slight chance of rain showers
through early afternoon, then rain showers likely by mid
afternoon. Waves building to 5 to 8 feet occasionally to 10 feet.
.THURSDAY NIGHT...East winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. Rain showers. Waves building to 6 to
9 feet occasionally to 11 feet, then subsiding to 2 to 4 feet.
.FRIDAY...Southwest winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. A chance of rain showers. Waves
building to 3 to 5 feet occasionally to 7 feet.
.FRIDAY NIGHT...Southwest winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...Southwest winds 10 to 20 knots veering west. A chance
of rain showers. Waves calm to 2 feet.
.SUNDAY...Southwest winds 10 to 20 knots backing south. Waves
calm to 2 feet.

$$

LSZ263-011000-
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-
959 PM EDT Tue Apr 30 2024

.REST OF TONIGHT...East winds 5 to 15 knots increasing to 15 to
25 knots after midnight, then to 20 to 30 knots late. A chance of
rain showers by late evening, then rain showers after midnight.
Waves calm to 2 feet building to 4 to 7 feet occasionally to 9
feet.
.WEDNESDAY...East winds 20 to 30 knots backing north in the
afternoon, then becoming west 10 to 20 knots late. Patchy fog
through early afternoon. A chance of rain showers. Waves
subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots veering northwest
after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...East winds 5 to 15 knots becoming northeast 15 to
25 knots by mid afternoon. A chance of rain showers. Waves
building to 2 to 4 feet.
.THURSDAY NIGHT...East winds 15 to 25 knots increasing to 20 to
30 knots after midnight. Rain showers. Waves building to 3 to
5 feet occasionally to 7 feet.
.FRIDAY...Southwest winds 20 to 30 knots. A chance of rain
showers. Waves building to 3 to 6 feet occasionally to 8 feet.
.FRIDAY NIGHT...Southwest winds 15 to 25 knots diminishing to
5 to 15 knots after midnight. Waves subsiding to 1 to 3 feet.
.SATURDAY...Southwest winds 10 to 20 knots diminishing to 5 to
15 knots. Waves subsiding to calm to 2 feet, then building to
1 to 3 feet.
.SUNDAY...Southwest winds 10 to 20 knots becoming south 5 to
15 knots. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.

$$

LSZ264-011000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
959 PM EDT Tue Apr 30 2024

.REST OF TONIGHT...Southeast winds less than 10 knots becoming
east 10 to 20 knots after midnight, then increasing to 15 to
25 knots late. A slight chance of rain showers by late evening,
then rain showers after midnight. Waves calm to 2 feet building
to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...East winds 15 to 25 knots backing northeast in the
afternoon, then backing northwest late. Patchy fog. Rain showers
likely through early afternoon. A chance of rain showers by mid
afternoon. Waves building to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 knots diminishing to
5 to 15 knots after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...North winds 5 to 15 knots becoming east 10 to
20 knots by mid afternoon. A slight chance of rain showers by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...East winds 15 to 25 knots increasing to 20 to
30 knots after midnight. Rain showers likely. Waves building to
3 to 5 feet occasionally to 7 feet.
.FRIDAY...South winds 20 to 30 knots becoming southwest 15 to
25 knots by mid afternoon. A chance of showers. Waves building to
3 to 6 feet occasionally to 8 feet.
.FRIDAY NIGHT...Southwest winds 15 to 25 knots diminishing to
5 to 15 knots after midnight. Waves subsiding to 1 to 3 feet.
.SATURDAY...Southwest winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.SUNDAY...West winds 5 to 15 knots backing southwest. Waves
building to 1 to 3 feet, then subsiding to calm to 2 feet.

$$

LSZ265-011000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
959 PM EDT Tue Apr 30 2024

.REST OF TONIGHT...Southeast winds 5 to 15 knots becoming east 15
to 25 knots late. A slight chance of rain showers by late
evening, then rain showers after midnight. Waves calm to 2 feet
building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...East winds 10 to 20 knots becoming northwest 15 to
25 knots in the afternoon, then increasing to 20 to 30 knots
late. Patchy fog. A chance of rain showers. Waves subsiding to
2 to 4 feet, then building to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...West winds 20 to 30 knots diminishing to 5 to
15 knots. Waves subsiding to calm to 2 feet.
.THURSDAY...Northwest winds 5 to 15 knots veering east by mid
afternoon. A chance of rain showers by mid afternoon. Waves calm
to 2 feet.
.THURSDAY NIGHT...East winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Rain showers. Waves building to 2 to
4 feet.
.FRIDAY...South winds 15 to 25 knots. A chance of showers. Waves
subsiding to calm to 2 feet.
.FRIDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight. Waves calm to 2 feet.
.SATURDAY...Southwest winds 10 to 20 knots. A chance of rain
showers. Waves calm to 2 feet.
.SUNDAY...West winds 10 to 20 knots backing south. Waves calm to
2 feet.

$$

LSZ266-011000-
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-
959 PM EDT Tue Apr 30 2024

.REST OF TONIGHT...Southeast winds 5 to 15 knots becoming east
10 to 20 knots late. Patchy fog after midnight. Rain showers
after midnight. Waves calm to 2 feet building to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY...East winds 15 to 25 knots becoming northwest 20 to
30 knots late. Patchy fog. A chance of rain showers. Waves
building to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...Northwest winds 20 to 30 knots diminishing to
10 to 20 knots after midnight. Waves building to 5 to 8 feet
occasionally to 10 feet, then subsiding to 2 to 4 feet.
.THURSDAY...Northwest winds 5 to 15 knots veering east by mid
afternoon. A chance of rain showers by mid afternoon. Waves
subsiding to calm to 2 feet.
.THURSDAY NIGHT...East winds 10 to 20 knots increasing to 20 to
30 knots after midnight. Rain showers likely. Waves building to
3 to 5 feet occasionally to 7 feet.
.FRIDAY...South winds 20 to 30 knots diminishing to 15 to
25 knots by mid afternoon. A chance of showers. Waves building to
3 to 6 feet occasionally to 8 feet.
.FRIDAY NIGHT...South winds 10 to 20 knots. Waves subsiding to
1 to 3 feet.
.SATURDAY...Southwest winds 10 to 20 knots veering west. A chance
of rain showers. Waves subsiding to calm to 2 feet.
.SUNDAY...West winds 10 to 20 knots backing south. Waves calm to
2 feet.

$$

LSZ267-011000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
959 PM EDT Tue Apr 30 2024

.REST OF TONIGHT...Southeast winds 5 to 15 knots increasing to
10 to 20 knots late. Patchy fog. Rain showers likely after
midnight. Waves 1 to 3 feet subsiding to calm to 2 feet, then
building to 1 to 3 feet.
.WEDNESDAY...Southeast winds 15 to 25 knots becoming west 20 to
30 knots late. Patchy fog through early afternoon. Rain showers
likely through early afternoon, then a chance of rain showers by
mid afternoon. Waves building to 3 to 6 feet occasionally to
8 feet, then subsiding to 1 to 3 feet.
.WEDNESDAY NIGHT...West winds 20 to 30 knots diminishing to 15 to
25 knots after midnight, then becoming northwest 10 to 20 knots
late. Waves building to 5 to 8 feet occasionally to 10 feet, then
subsiding to 2 to 4 feet.
.THURSDAY...Northwest winds 5 to 15 knots veering northeast by
mid afternoon. A slight chance of rain showers by mid afternoon.
Waves subsiding to calm to 2 feet.
.THURSDAY NIGHT...East winds 10 to 20 knots becoming southeast
20 to 30 knots after midnight. Rain showers likely. Waves
building to 3 to 5 feet occasionally to 7 feet.
.FRIDAY...Southeast winds 15 to 25 knots backing east by mid
afternoon. Showers likely through early afternoon, then a chance
of showers by mid afternoon. Waves building to 3 to 6 feet
occasionally to 8 feet, then subsiding to 1 to 3 feet.
.FRIDAY NIGHT...East winds 10 to 20 knots veering south after
midnight. A chance of rain showers. Waves subsiding to calm to
2 feet.
.SATURDAY...South winds 10 to 20 knots veering west. A chance of
rain showers. Waves calm to 2 feet.
.SUNDAY...West winds 10 to 20 knots backing southwest. Waves calm
to 2 feet.

$$
LSZ261-011000-
MAFOR 0103/
Superior West 11230 11246 11146 11140 11830 11620 12610. Waves 1
to 2 feet building to 4 to 8 feet overnight subsiding to 2 to 4
feet by Wednesday evening.

Superior North Central 11300 11220 12236 11230 11820 12730. Waves
1 to 3 feet overnight. Waves 3 to 6 feet Wednesday and Wednesday
evening.

Superior South Central 11310 11320 11336 12230 13740. Waves 1 to
3 feet overnight. Waves 3 to 6 feet Wednesday and Wednesday
evening.

Superior East 11300 11310 11326 11336 11330 11630 11640 11740.
Waves 1 to 2 feet overnight. Waves 2 to 4 feet building to 3 to 7
feet Wednesday and Wednesday evening.

$$

Jablonski

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

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