Great Lakes Forecast
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FZUS63 KMQT 121951
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
351 PM EDT Tue Sep 12 2017

For waters beyond five 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 29.9 inch ridge extending westward across the Upper
Great Lakes will gradually weaken to 29.8 inches through tonight.
A weak 29.7 inch trough over northern Ontario today will
dissipate over Lake Superior on Wednesday. A 30.2 inch ridge will
then build across northern Ontario through Friday as 29.5 inch low
pressure develops over the Plains. The trough will reach the
Upper Mississippi Valley on Saturday, then shift northeastward
across the Upper Great Lakes on Sunday as the ridge extends over
the Lower Great Lakes.

LSZ162-130400-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
351 PM EDT Tue Sep 12 2017 /251 PM CDT Tue Sep 12 2017/

.LATE THIS AFTERNOON...Southwest winds 5 to 15 knots. Waves calm
to 2 feet.
.TONIGHT...South winds 5 to 15 knots. Waves calm to 2 feet.
.WEDNESDAY...Southwest winds 5 to 15 knots becoming east less
than 10 knots late. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots backing northeast
after midnight, then veering east late. A slight chance of
showers and thunderstorms. Waves calm to 2 feet.
.THURSDAY...East winds 5 to 15 knots backing northeast by mid
afternoon. A chance of showers. A slight chance of thunderstorms
by mid afternoon. Waves building to 1 to 3 feet, then subsiding
to calm to 2 feet.
.THURSDAY NIGHT...East winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.FRIDAY...East winds 10 to 20 knots backing northeast by mid
afternoon. A chance of showers. Waves building to 2 to 4 feet.
.FRIDAY NIGHT...East winds 10 to 20 knots. A chance of showers.
Waves building to 3 to 5 feet occasionally to 7 feet, then
subsiding to 1 to 3 feet.
.SATURDAY...Southeast winds 5 to 15 knots becoming south 10 to
20 knots. A chance of showers and thunderstorms. Waves subsiding
to calm to 2 feet, then building to 1 to 3 feet.
.SUNDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots. Waves building to 2 to 4 feet, then subsiding to 1 to
3 feet.

$$

LSZ263-130400-
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-
351 PM EDT Tue Sep 12 2017

.LATE THIS AFTERNOON...Southwest winds 5 to 15 knots. Waves calm
to 2 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest after
midnight. Waves calm to 2 feet.
.WEDNESDAY...Southwest winds 5 to 15 knots becoming east less
than 10 knots late. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots. A slight chance of
thunderstorms through midnight. A slight chance of showers. Waves
building to 1 to 3 feet.
.THURSDAY...East winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. A chance of showers. Waves subsiding
to calm to 2 feet.
.THURSDAY NIGHT...East winds 5 to 15 knots backing northeast
after midnight. A chance of showers. Waves calm to 2 feet.
.FRIDAY...Northeast winds 5 to 15 knots increasing to 10 to
20 knots by mid afternoon. A chance of showers. Waves building to
2 to 4 feet.
.FRIDAY NIGHT...East winds 5 to 15 knots veering southeast after
midnight. A chance of showers. Waves subsiding to 1 to 3 feet.
.SATURDAY...South winds 5 to 15 knots increasing to 10 to
20 knots. A chance of showers and thunderstorms. Waves subsiding
to calm to 2 feet, then building to 1 to 3 feet.
.SUNDAY...Southwest winds 15 to 25 knots becoming west 10 to
20 knots. Waves building to 3 to 5 feet occasionally to 7 feet,
then subsiding to 2 to 4 feet.

$$

LSZ264-130400-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
351 PM EDT Tue Sep 12 2017

.LATE THIS AFTERNOON...Southwest winds 5 to 15 knots. Waves 1 to
3 feet subsiding to calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest after
midnight. Waves calm to 2 feet.
.WEDNESDAY...Southwest winds 5 to 15 knots becoming southeast
less than 10 knots late. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots. A slight chance of
showers after midnight. Waves building to 1 to 3 feet.
.THURSDAY...East winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. A chance of showers. Waves 1 to
3 feet.
.THURSDAY NIGHT...East winds 5 to 15 knots backing northeast
after midnight. A chance of showers. Waves subsiding to calm to
2 feet, then building to 1 to 3 feet.
.FRIDAY...Northeast winds 5 to 15 knots veering east by mid
afternoon. A chance of showers. Waves building to 1 to 3 feet.
.FRIDAY NIGHT...East winds 5 to 15 knots becoming southeast 10 to
20 knots after midnight. A chance of showers. Waves building to
2 to 4 feet.
.SATURDAY...Southeast winds 10 to 20 knots veering south. A
chance of showers and thunderstorms. Waves subsiding to 1 to
3 feet, then building to 3 to 5 feet occasionally to 7 feet.
.SUNDAY...Southwest winds 15 to 25 knots veering west. A chance
of thunderstorms. A chance of showers. Waves building to 3 to
6 feet occasionally to 8 feet.

$$

LSZ265-130400-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
351 PM EDT Tue Sep 12 2017

.LATE THIS AFTERNOON...Southeast winds 5 to 15 knots. Waves calm
to 2 feet.
.TONIGHT...South winds 10 to 20 knots becoming southwest 5 to
15 knots late. Waves calm to 2 feet.
.WEDNESDAY...Southwest winds 5 to 15 knots backing south in the
afternoon, then backing east late. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 10 to 20 knots becoming southeast
5 to 15 knots after midnight. A slight chance of showers after
midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 5 to 15 knots increasing to 10 to
20 knots by mid afternoon. A slight chance of showers by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...South winds 5 to 15 knots increasing to 10 to
20 knots after midnight. A chance of showers. Waves calm to
2 feet.
.FRIDAY...South winds 10 to 20 knots backing east by mid
afternoon. A chance of showers through early afternoon. Waves
calm to 2 feet.
.FRIDAY NIGHT...Southeast winds 10 to 20 knots veering south
after midnight. Waves building to 1 to 3 feet.
.SATURDAY...South winds 10 to 20 knots increasing to 15 to
25 knots. A chance of thunderstorms. Showers likely. Waves
building to 2 to 4 feet.
.SUNDAY...West winds 15 to 25 knots. A chance of thunderstorms. A
chance of showers. Waves subsiding to 1 to 3 feet, then building
to 2 to 4 feet.

$$

LSZ266-130400-
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-
351 PM EDT Tue Sep 12 2017

.LATE THIS AFTERNOON...Southwest winds less than 10 knots. Waves
calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots
after midnight. Waves calm to 2 feet.
.WEDNESDAY...South winds 10 to 20 knots diminishing to 5 to
15 knots in the afternoon, then becoming southeast less than
10 knots late. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots veering south after
midnight, then becoming southeast 10 to 20 knots late. A slight
chance of showers after midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 10 to 20 knots. A slight chance of
showers. Waves calm to 2 feet.
.THURSDAY NIGHT...South winds 10 to 20 knots. A chance of
showers. Waves building to 1 to 3 feet.
.FRIDAY...South winds 10 to 20 knots backing southeast by mid
afternoon. A chance of showers. Waves subsiding to calm to
2 feet, then building to 1 to 3 feet.
.FRIDAY NIGHT...Southeast winds 15 to 25 knots veering south
after midnight. Waves building to 2 to 4 feet.
.SATURDAY...South winds 15 to 25 knots. A chance of showers.
Waves building to 3 to 5 feet occasionally to 7 feet.
.SUNDAY...South winds 15 to 25 knots veering west. A chance of
thunderstorms. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet.

$$

LSZ267-130400-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
351 PM EDT Tue Sep 12 2017

.LATE THIS AFTERNOON...West winds 5 to 15 knots. Waves calm to 2
feet.
.TONIGHT...Southeast winds 5 to 15 knots veering south after
midnight, then increasing to 10 to 20 knots late. Waves calm to
2 feet.
.WEDNESDAY...South winds 5 to 15 knots backing east late. Waves
calm to 2 feet.
.WEDNESDAY NIGHT...Southeast winds 5 to 15 knots veering south
after midnight, then backing southeast late. Waves calm to
2 feet.
.THURSDAY...Southeast winds 10 to 20 knots. A slight chance of
showers through early afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...South winds 10 to 20 knots. A chance of
showers. Waves building to 1 to 3 feet.
.FRIDAY...South winds 10 to 20 knots backing southeast by mid
afternoon. Waves subsiding to calm to 2 feet.
.FRIDAY NIGHT...South winds 10 to 20 knots. Waves building to
1 to 3 feet.
.SATURDAY...South winds 15 to 25 knots. A chance of showers.
Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet.
.SUNDAY...South winds 15 to 25 knots veering west. A chance of
showers. Waves building to 3 to 5 feet occasionally to 7 feet.

$$

LSZ261-130400-
MAFOR 1221/
Superior West 13400 14500 11400. Waves 1 foot or less.

Superior North Central 11510 12410 13510 12500. Waves 1 to 3
feet.

Superior South Central 12300 12410 13400 11300. Waves 2 feet or
less.

Superior East 11400 11300 14410 11410 11400. Waves 1 to 2 feet.

$$

Kluber

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

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



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