Great Lakes Forecast
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FZUS63 KMQT 221939
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
339 PM 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 29.1 inch low pressure over Western Hudson Bay this
afternoon is dragging a 29.7 inch shortwave trough across Lake
Superior that will dissipate as it moves eastward later 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 Lake Huron 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.

LSZ162-230345-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
339 PM EDT Sun Oct 22 2017 /239 PM CDT Sun Oct 22 2017/

...GALE WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
AFTERNOON...

.LATE THIS AFTERNOON...Southwest winds 15 to 25 knots. Waves 3 to
6 feet occasionally to 8 feet.
.TONIGHT...Southwest winds 15 to 25 knots increasing to 20 to
30 knots after midnight, then becoming south 15 to 25 knots late.
A slight chance of showers after midnight. Waves subsiding to
2 to 4 feet, then building to 3 to 5 feet occasionally to 7 feet.
.MONDAY...Southwest winds 20 to 30 knots becoming west 15 to
25 knots in the afternoon. A chance of showers. Waves subsiding
to 1 to 3 feet.
.MONDAY NIGHT...Northwest winds 15 to 25 knots becoming north
gales to 35 knots after midnight. A chance of showers. Waves
building to 6 to 9 feet occasionally to 11 feet.
.TUESDAY...North gales to 40 knots diminishing to 20 to 30 knots
by mid afternoon. A chance of rain showers. Waves building to
7 to 10 feet occasionally to 13 feet, then subsiding to 4 to
7 feet occasionally to 9 feet.
.TUESDAY NIGHT...North winds 15 to 25 knots becoming northwest
10 to 20 knots after midnight. A chance of rain showers after
midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...West winds 10 to 20 knots veering north by mid
afternoon. A chance of rain showers through early afternoon.
Waves calm to 2 feet.
.WEDNESDAY NIGHT...Southeast winds 10 to 20 knots. A chance of
rain showers after midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 15 to 25 knots becoming northeast
gales to 35 knots. A chance of rain showers, then rain showers
likely. Waves building to 7 to 10 feet occasionally to 13 feet.
.FRIDAY...Northeast gales to 35 knots becoming north 20 to
30 knots. Rain showers likely, then a chance of rain showers.
Waves building to 8 to 11 feet occasionally to 14 feet, then
subsiding to 3 to 5 feet occasionally to 7 feet.

$$

LSZ263-230345-
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-
339 PM EDT Sun Oct 22 2017

...GALE WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
EVENING...

.LATE THIS AFTERNOON...Southwest winds 15 to 25 knots. Waves 4 to
8 feet occasionally to 10 feet.
.TONIGHT...Southwest winds 10 to 20 knots increasing to 15 to
25 knots after midnight. A slight chance of showers 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
20 to 30 knots after midnight, then increasing to gales to
35 knots late. A chance of showers through midnight, then showers
likely after midnight. Waves subsiding to 1 to 3 feet, then
building to 7 to 10 feet occasionally to 13 feet.
.TUESDAY...North gales to 40 knots. A chance of rain showers.
Waves building to 10 to 14 feet occasionally to 18 feet, then
subsiding to 7 to 10 feet occasionally to 13 feet.
.TUESDAY NIGHT...North winds 20 to 30 knots becoming northwest
10 to 20 knots after midnight. Waves subsiding to 1 to 3 feet.
.WEDNESDAY...North winds 5 to 15 knots. A chance of rain showers.
Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots veering southeast
after midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 15 to 25 knots becoming northeast
20 to 30 knots. A chance of rain showers, then rain showers
likely. Waves building to 7 to 10 feet occasionally to 13 feet.
.FRIDAY...Northeast gales to 35 knots becoming north 20 to
30 knots. Rain showers likely. Waves building to 8 to 11 feet
occasionally to 14 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.

$$

LSZ264-230345-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
339 PM EDT Sun Oct 22 2017

...GALE WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
EVENING...

.LATE THIS AFTERNOON...Southwest winds 15 to 25 knots. Isolated
showers. Waves 4 to 8 feet occasionally to 10 feet.
.TONIGHT...Southwest winds 15 to 25 knots diminishing to 10 to
20 knots after midnight, then increasing to 15 to 25 knots late.
A slight chance of showers after midnight. Waves subsiding to
2 to 4 feet.
.MONDAY...South winds 15 to 25 knots becoming southwest 10 to
20 knots in the afternoon, then veering west late. A slight
chance of showers. Waves building to 3 to 5 feet occasionally to
7 feet, then subsiding to 2 to 4 feet.
.MONDAY NIGHT...West winds 5 to 15 knots becoming north 20 to
30 knots after midnight, then increasing to gales to 35 knots
late. A chance of showers through midnight, then showers after
midnight. Waves subsiding to 1 to 3 feet, then building to 7 to
10 feet occasionally to 13 feet.
.TUESDAY...North gales to 45 knots. Rain showers likely through
early afternoon, then a chance of rain showers by mid afternoon.
Waves building to 12 to 17 feet occasionally to 21 feet, then
subsiding to 10 to 14 feet occasionally to 18 feet.
.TUESDAY NIGHT...North gales to 35 knots diminishing to 10 to
20 knots after midnight. A chance of rain showers. Waves
subsiding to 2 to 4 feet.
.WEDNESDAY...North winds 5 to 15 knots. Waves subsiding to calm
to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...Southeast winds 10 to 20 knots becoming northeast
20 to 30 knots. A chance of rain showers, then rain showers
likely. Waves building to 6 to 9 feet occasionally to 11 feet.
.FRIDAY...Northeast winds 20 to 30 knots. A chance of rain
showers, then rain showers likely. Waves building to 7 to 10 feet
occasionally to 13 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.

$$

LSZ265-230345-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
339 PM EDT Sun Oct 22 2017

...GALE WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
EVENING...

.LATE THIS AFTERNOON...West winds 10 to 20 knots. Scattered
showers. Waves 1 to 3 feet.
.TONIGHT...Southwest winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Waves 1 to 3 feet.
.MONDAY...South winds 15 to 25 knots becoming west 10 to 20 knots
late. A slight chance of showers by mid afternoon. Waves
subsiding to calm to 2 feet, then building to 1 to 3 feet.
.MONDAY NIGHT...Northwest winds 10 to 20 knots becoming north
15 to 25 knots after midnight, then increasing to 20 to 30 knots
late. A chance of showers through midnight, then showers after
midnight. Waves building to 4 to 7 feet occasionally to 9 feet.
.TUESDAY...North gales to 40 knots. Showers. Waves building to
12 to 17 feet occasionally to 21 feet, then subsiding to 11 to
15 feet occasionally to 19 feet.
.TUESDAY NIGHT...North gales to 35 knots becoming northwest 15 to
25 knots after midnight. Rain showers likely through midnight.
Waves subsiding to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots veering north by mid
afternoon. A chance of rain showers. Waves subsiding to calm to
2 feet.
.WEDNESDAY NIGHT...Northeast winds 10 to 20 knots veering
southeast after midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 10 to 20 knots becoming east 20 to
30 knots. A chance of rain showers. Waves building to 5 to 8 feet
occasionally to 10 feet.
.FRIDAY...Northeast winds 20 to 30 knots diminishing to 15 to
25 knots. Rain showers likely. Waves building to 7 to 10 feet
occasionally to 13 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.

$$

LSZ266-230345-
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-
339 PM EDT Sun Oct 22 2017

...GALE WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
EVENING...

.LATE THIS AFTERNOON...Southwest winds 10 to 20 knots. Scattered
showers. Waves 4 to 8 feet occasionally to 10 feet.
.TONIGHT...Southwest winds 10 to 20 knots increasing to 15 to
25 knots after midnight, then becoming south 10 to 20 knots late.
A slight chance of showers through midnight. Waves subsiding to
2 to 4 feet.
.MONDAY...South winds 15 to 25 knots diminishing to 10 to
20 knots late. A slight chance of showers by mid afternoon. Waves
2 to 4 feet.
.MONDAY NIGHT...Northwest winds 10 to 20 knots veering north
after midnight, then increasing to 20 to 30 knots late. A chance
of showers through midnight, then showers after midnight. Waves
subsiding to 1 to 3 feet, then building to 5 to 8 feet
occasionally to 10 feet.
.TUESDAY...North gales to 45 knots. Showers. Waves building to
15 to 20 feet occasionally to 25 feet, then subsiding to 12 to
17 feet occasionally to 21 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
3 to 6 feet occasionally to 8 feet.
.WEDNESDAY...North winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...Northeast winds 10 to 20 knots veering east
after midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 10 to 20 knots becoming northeast
15 to 25 knots. A chance of rain showers. Waves building to 5 to
8 feet occasionally to 10 feet.
.FRIDAY...Northeast winds 20 to 30 knots diminishing to 15 to
25 knots. Rain showers likely. Waves building to 7 to 10 feet
occasionally to 13 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.

$$

LSZ267-230345-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
339 PM EDT Sun Oct 22 2017

...GALE WATCH IN EFFECT FROM TUESDAY MORNING THROUGH TUESDAY
EVENING...

.LATE THIS AFTERNOON...West winds 10 to 20 knots. Showers. Waves
2 to 4 feet subsiding to 1 to 3 feet.
.TONIGHT...Southwest winds 5 to 15 knots increasing to 10 to
20 knots after midnight. A chance of showers through midnight.
Waves subsiding to calm to 2 feet.
.MONDAY...South winds 10 to 20 knots increasing to 15 to 25 knots
in the afternoon, then diminishing to 10 to 20 knots late. A
slight chance of showers by mid afternoon. Waves building to 1 to
3 feet, then subsiding to calm to 2 feet.
.MONDAY NIGHT...Northeast winds 10 to 20 knots becoming north
15 to 25 knots after midnight, then increasing to 20 to 30 knots
late. A chance of showers through midnight, then showers 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, then subsiding to 9 to
12 feet occasionally to 15 feet.
.TUESDAY NIGHT...North gales to 35 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
3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...North winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...Northeast winds 10 to 20 knots veering east
after midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 10 to 20 knots becoming northeast
20 to 30 knots. A chance of rain showers. Waves building to 3 to
5 feet occasionally to 7 feet.
.FRIDAY...Northeast winds 20 to 30 knots becoming east 15 to
25 knots. Showers likely. Waves building to 3 to 6 feet
occasionally to 8 feet, then subsiding to 2 to 4 feet.

$$

LSZ261-230345-
MAFOR 2221/
Superior West 11530 11520 12530 11430 12530 11620. Waves 3 to 6
feet.

Superior North Central 12530 12520 13430 11530. Waves 5 to 8 feet
subsiding to 3 to 5 feet tonight. Waves 2 to 4 feet Monday.

Superior South Central 11520 11510 12520 14420. Scattered showers
early this evening. Waves 1 to 3 feet.

Superior East 11616 12520 12510 13420. Chance of showers late
this evening tonight. Waves 2 to 4 feet.

$$

Borchardt

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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