Great Lakes Forecast
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FZUS63 KMQT 221352
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
952 AM EDT Sun Oct 22 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 29.8 inch trough is sweeping across Lake Superior
today and will dissipate as it continues eastward tonight. A new
low pressure trough of 29.5 inches moving across south central
Canada and the Northern Plains tonight will weaken and reach
central Lake Superior Monday afternoon at 29.7 inches. The trough
will then give way to low pressure of 29.5 inches organizing over
the Ohio Valley on Monday. This low will deepen to 29.1 inches as
it lifts north to near Drummond Island by Tuesday morning. As the
low then weakens to 29.4 inches while tracking toward James Bay
Tuesday night, a 29.5 inch trough will linger back across the
Upper Great Lakes. The trough will drop south on Wednesday as a
ridge of 29.8 inches builds southeast into northern Ontario. A
29.5 inch trough will then move out across the Plains States on
Thursday.

LSZ162-222200-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
952 AM EDT Sun Oct 22 2017 /852 AM CDT Sun Oct 22 2017/

.REST OF TODAY...Southwest winds 20 to 30 knots diminishing to
15 to 25 knots late. Waves 3 to 6 feet occasionally to 8 feet.
.TONIGHT...Southwest winds 15 to 25 knots increasing to 20 to
30 knots after midnight. Isolated showers after midnight. Waves
subsiding to 2 to 4 feet, then building to 3 to 5 feet
occasionally to 7 feet.
.MONDAY...Southwest winds 15 to 25 knots veering west late. A
slight chance of showers. Waves subsiding to 2 to 4 feet.
.MONDAY NIGHT...Northwest winds 20 to 30 knots becoming north
gales to 35 knots after midnight. A chance of showers. Waves
building to 5 to 8 feet occasionally to 10 feet.
.TUESDAY...North gales to 35 knots diminishing to 20 to 30 knots
by mid afternoon. A chance of rain showers. Waves building to
6 to 9 feet occasionally to 11 feet, then subsiding to 4 to
7 feet occasionally to 9 feet.
.TUESDAY NIGHT...Northwest winds 20 to 30 knots diminishing to
10 to 20 knots after midnight. A chance of rain showers after
midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...North winds 10 to 20 knots veering southeast. A
chance of rain showers. Waves building to 1 to 3 feet.
.THURSDAY...Southeast winds 15 to 25 knots becoming northwest
20 to 30 knots. A chance of rain showers. Waves building to 3 to
6 feet occasionally to 8 feet.

$$

LSZ263-222200-
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-
952 AM EDT Sun Oct 22 2017

.REST OF TODAY...Southwest winds 20 to 30 knots diminishing to
15 to 25 knots late. Isolated showers. Waves 4 to 8 feet
occasionally to 10 feet, then subsiding to 4 to 7 feet
occasionally to 9 feet.
.TONIGHT...Southwest winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Waves subsiding to 3 to 5 feet
occasionally to 7 feet.
.MONDAY...Southwest winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon, then veering west late. A chance of
showers. Waves subsiding to 2 to 4 feet.
.MONDAY NIGHT...Northwest winds 15 to 25 knots becoming north
gales to 35 knots after midnight. A chance of showers. Waves
building to 5 to 8 feet occasionally to 10 feet.
.TUESDAY...North gales to 40 knots. A chance of rain showers.
Waves building to 7 to 11 feet occasionally to 14 feet.
.TUESDAY NIGHT...North winds 20 to 30 knots diminishing to 10 to
20 knots after midnight. Waves subsiding to 2 to 4 feet.
.WEDNESDAY...North winds 5 to 15 knots veering southeast. Waves
subsiding to calm to 2 feet.
.THURSDAY...Southeast winds 15 to 25 knots becoming north 20 to
30 knots. Rain showers. Waves building to 4 to 7 feet
occasionally to 9 feet.

$$

LSZ264-222200-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
952 AM EDT Sun Oct 22 2017

.REST OF TODAY...Southwest winds 20 to 30 knots diminishing to
15 to 25 knots late. Scattered showers. Waves 3 to 6 feet
occasionally to 8 feet building to 5 to 8 feet occasionally to
10 feet, then subsiding to 4 to 7 feet occasionally to 9 feet.
.TONIGHT...Southwest winds 10 to 20 knots. Waves subsiding to
3 to 5 feet occasionally to 7 feet.
.MONDAY...South winds 10 to 20 knots veering southwest in the
afternoon. A chance of showers. Waves subsiding to 2 to 4 feet.
.MONDAY NIGHT...West winds 10 to 20 knots becoming north gales to
35 knots after midnight. A slight chance of showers through
midnight, then showers likely after midnight. Waves building to
4 to 7 feet occasionally to 9 feet.
.TUESDAY...North gales to 40 knots. Showers. Waves building to
10 to 14 feet occasionally to 18 feet.
.TUESDAY NIGHT...North gales to 35 knots diminishing to 15 to
25 knots after midnight. A chance of rain showers. Waves
subsiding to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...North winds 10 to 20 knots veering east. Waves
subsiding to calm to 2 feet.
.THURSDAY...Southeast winds 15 to 25 knots backing east. A chance
of rain showers, then rain showers. Waves building to 4 to 7 feet
occasionally to 9 feet.

$$

LSZ265-222200-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
952 AM EDT Sun Oct 22 2017

.REST OF TODAY...West winds 15 to 25 knots diminishing to 10 to
20 knots late. Numerous showers by late morning, then scattered
showers by mid afternoon. Waves 2 to 4 feet subsiding to 1 to
3 feet.
.TONIGHT...Southwest winds 10 to 20 knots. Waves 1 to 3 feet.
.MONDAY...South winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon, then veering west late. A slight
chance of showers by mid afternoon. Waves subsiding to calm to
2 feet.
.MONDAY NIGHT...West winds 10 to 20 knots becoming northwest
15 to 25 knots after midnight. A slight chance of showers through
midnight, then showers likely after midnight. Waves building to
2 to 4 feet.
.TUESDAY...North gales to 40 knots. Showers. Waves building to
11 to 15 feet occasionally to 19 feet.
.TUESDAY NIGHT...North gales to 40 knots diminishing to 15 to
25 knots after midnight. Rain showers likely through midnight,
then a chance of rain showers after midnight. Waves subsiding to
4 to 7 feet occasionally to 9 feet.
.WEDNESDAY...North winds 10 to 20 knots veering northeast. Waves
subsiding to calm to 2 feet.
.THURSDAY...Southeast winds 15 to 25 knots increasing to 20 to
30 knots. A chance of rain showers, then rain showers likely.
Waves building to 4 to 7 feet occasionally to 9 feet.

$$

LSZ266-222200-
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-
952 AM EDT Sun Oct 22 2017

.REST OF TODAY...South winds 15 to 25 knots veering west in the
afternoon. Numerous showers. Waves 3 to 6 feet occasionally to
8 feet building to 5 to 8 feet occasionally to 10 feet, then
subsiding to 4 to 7 feet occasionally to 9 feet.
.TONIGHT...Southwest winds 10 to 20 knots increasing to 15 to
25 knots late. Isolated showers through midnight. Waves subsiding
to 2 to 4 feet.
.MONDAY...South winds 15 to 25 knots becoming southwest 10 to
20 knots late. A slight chance of showers by mid afternoon. Waves
subsiding to 1 to 3 feet.
.MONDAY NIGHT...West winds 10 to 20 knots becoming north 15 to
25 knots after midnight. A chance of showers through midnight,
then showers after midnight. Waves building to 2 to 4 feet.
.TUESDAY...North gales to 40 knots. Showers. Waves building to
11 to 15 feet occasionally to 19 feet.
.TUESDAY NIGHT...North gales to 40 knots diminishing to 20 to
30 knots after midnight. Rain showers likely through midnight,
then a chance of rain showers after midnight. Waves subsiding to
4 to 7 feet occasionally to 9 feet.
.WEDNESDAY...North winds 15 to 25 knots becoming northeast 10 to
20 knots. Waves subsiding to calm to 2 feet.
.THURSDAY...Southeast winds 15 to 25 knots increasing to 20 to
30 knots. A chance of rain showers, then rain showers likely.
Waves building to 4 to 8 feet occasionally to 10 feet.

$$

LSZ267-222200-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
952 AM EDT Sun Oct 22 2017

.REST OF TODAY...South winds 20 to 30 knots becoming west 15 to
25 knots in the afternoon, then diminishing to 10 to 20 knots
late. Scattered showers by late morning, then showers by mid
afternoon. Waves 3 to 5 feet occasionally to 7 feet subsiding to
1 to 3 feet.
.TONIGHT...Southwest winds 10 to 20 knots. Scattered showers
through midnight. Waves 1 to 3 feet.
.MONDAY...South winds 10 to 20 knots. A slight chance of showers
by mid afternoon. Waves 1 to 3 feet.
.MONDAY NIGHT...Southwest winds 10 to 20 knots veering north
after midnight. A chance of showers through midnight, then
showers after midnight. Waves subsiding to calm to 2 feet.
.TUESDAY...North winds 20 to 30 knots with a few gale force gusts
to 35 knots by mid afternoon. Showers. Waves building to 7 to 10
feet occasionally to 13 feet.
.TUESDAY NIGHT...North winds 20 to 30 knots. Rain showers through
midnight, then a chance of rain showers after midnight. Waves
building to 8 to 11 feet occasionally to 14 feet, then subsiding
to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY...North winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of rain showers. Waves subsiding to calm to
2 feet.
.THURSDAY...Southeast winds 15 to 25 knots increasing to 20 to
30 knots. A chance of rain showers. Waves building to 4 to 7 feet
occasionally to 9 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.

$$

LSZ261-222200-
MAFOR 2215/
Superior West 11540 12530 11520 14530. Chance of showers Monday
morning. Waves 3 to 7 feet.

Superior North Central 12540 12530 12520 11530 11430. Scattered
showers late this morning. Waves 5 to 8 feet this afternoon, subsiding
to 3 to 5 feet tonight.

Superior South Central 11646 11636 14520 11510 11420. Scattered
showers late this afternoon. Waves 1 to 4 feet this afternoon.

Superior East 11536 12626 12520 12510 11420. Scattered
showers late this afternoon through this evening. Waves 2 to 6
feet.

$$

KCW

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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