Great Lakes Forecast
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790
FZUS63 KMQT 121955
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
355 PM EDT Thu Oct 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 29.7 inch low pressure trough over Manitoba will
track northeast and pushes a 29.9 inch trough across Lake
Superior. A 30.2 inch ridge will briefly move over Lake Superior
Saturday while low pressure of 29.7 inches develops over the
Central Plains. Expect the low to deepen to 29.3 inches as it
moves to the Upper Great Lakes on Saturday night and to 29.1
inches by time it reaches southern Quebec on Sunday afternoon. In
wake of the low, high pressure of 30.4 inches over the Southern
plains on Sunday will extend a ridge of 30.2 inches over the
Great Lakes on Monday. A weak trough of 29.9 inches will quickly
pass over the area Tuesday followed by a secondary 30.1 inch
ridge.

LSZ162-130400-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
355 PM EDT Thu Oct 12 2017 /255 PM CDT Thu Oct 12 2017/

.LATE THIS AFTERNOON...South winds 10 to 20 knots. Waves 1 to
3 feet.
.TONIGHT...South winds 10 to 20 knots increasing to 15 to
25 knots after midnight, then veering southwest late. A slight
chance of drizzle. Waves building to 3 to 5 feet occasionally to
7 feet.
.FRIDAY...West winds 15 to 25 knots diminishing to 10 to 20 knots
late. Waves subsiding to 1 to 3 feet.
.FRIDAY NIGHT...West winds 5 to 15 knots veering north late.
Waves subsiding to calm to 2 feet.
.SATURDAY...East winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. A chance of showers by mid afternoon.
Waves building to 3 to 6 feet occasionally to 8 feet.
.SATURDAY NIGHT...Northeast winds 20 to 30 knots becoming north
gales to 35 knots after midnight. Showers. Waves building to 5 to
9 feet occasionally to 11 feet.
.SUNDAY...Northwest winds 20 to 30 knots diminishing to 10 to
20 knots by mid afternoon. A chance of showers. Waves subsiding
to 1 to 3 feet.
.SUNDAY NIGHT...West winds 10 to 20 knots. Waves 1 to 3 feet.
.MONDAY...West winds 10 to 20 knots becoming southwest 15 to
25 knots. Waves building to 3 to 5 feet occasionally to 7 feet.
.TUESDAY...West winds 15 to 25 knots becoming southwest 10 to
20 knots. Waves subsiding to calm to 2 feet, then building 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-
355 PM EDT Thu Oct 12 2017

.LATE THIS AFTERNOON...South winds 5 to 15 knots. Waves 1 to
3 feet.
.TONIGHT...South winds 10 to 20 knots veering southwest late. A
slight chance of drizzle after midnight. Waves building to 3 to
5 feet occasionally to 7 feet.
.FRIDAY...West winds 10 to 20 knots increasing to 15 to 25 knots
late. Waves building to 3 to 6 feet occasionally to 8 feet.
.FRIDAY NIGHT...West winds 10 to 20 knots veering northwest after
midnight, then becoming north 5 to 15 knots late. Waves subsiding
to calm to 2 feet.
.SATURDAY...East winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. A chance of showers by mid afternoon.
Waves building to 3 to 5 feet occasionally to 7 feet.
.SATURDAY NIGHT...Northeast winds 20 to 30 knots becoming north
gales to 35 knots after midnight. Rain showers. Waves building to
6 to 9 feet occasionally to 11 feet.
.SUNDAY...North winds 20 to 30 knots becoming northwest 10 to
20 knots by mid afternoon. A chance of rain showers. Waves
building to 7 to 10 feet occasionally to 13 feet, then subsiding
to 2 to 4 feet.
.SUNDAY NIGHT...West winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Waves subsiding to 1 to 3 feet.
.MONDAY...West winds 10 to 20 knots increasing to 15 to 25 knots.
Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet.
.TUESDAY...West winds 15 to 25 knots becoming southwest 5 to
15 knots. Waves subsiding to calm to 2 feet, then building to
1 to 3 feet.

$$

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

.LATE THIS AFTERNOON...South winds 10 to 20 knots. Waves 3 to
5 feet occasionally to 7 feet.
.TONIGHT...South winds 10 to 20 knots. Waves 3 to 5 feet
occasionally to 7 feet.
.FRIDAY...Southwest winds 15 to 25 knots veering west in the
afternoon. A slight chance of showers through early afternoon.
Waves building to 3 to 6 feet occasionally to 8 feet.
.FRIDAY NIGHT...West winds 10 to 20 knots veering northwest after
midnight, then diminishing to 5 to 15 knots late. Waves subsiding
to 1 to 3 feet.
.SATURDAY...East winds 5 to 15 knots increasing to 10 to 20 knots
by mid afternoon. A slight chance of showers by mid afternoon.
Waves subsiding to calm to 2 feet, then building to 1 to 3 feet.
.SATURDAY NIGHT...East winds 15 to 25 knots becoming northeast
gales to 35 knots after midnight. Showers. Waves building to 6 to
9 feet occasionally to 11 feet.
.SUNDAY...North gales to 35 knots becoming northwest 15 to
25 knots by mid afternoon. Showers likely through early
afternoon. Waves building to 8 to 11 feet occasionally to
14 feet, then subsiding to 3 to 6 feet occasionally to 8 feet.
.SUNDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm
to 2 feet, then building to 1 to 3 feet.
.MONDAY...West winds 10 to 20 knots increasing to 15 to 25 knots.
Waves building to 4 to 7 feet occasionally to 9 feet.
.TUESDAY...West winds 15 to 25 knots becoming southwest 5 to
15 knots. Waves subsiding to calm to 2 feet, then building to
1 to 3 feet.

$$

LSZ265-130400-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
355 PM EDT Thu Oct 12 2017

.LATE THIS AFTERNOON...South winds 10 to 20 knots. Waves 2 to
4 feet.
.TONIGHT...South winds 15 to 25 knots diminishing to 10 to
20 knots late. Waves subsiding to 1 to 3 feet.
.FRIDAY...Southwest winds 15 to 25 knots veering west in the
afternoon. Waves building to 2 to 4 feet.
.FRIDAY NIGHT...West winds 15 to 25 knots diminishing to 10 to
20 knots after midnight, then veering north late. Waves subsiding
to calm to 2 feet.
.SATURDAY...East winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. A chance of showers by mid afternoon.
Waves building to 2 to 4 feet.
.SATURDAY NIGHT...East winds 20 to 30 knots becoming northeast
gales to 35 knots after midnight. Showers. Waves building to 6 to
9 feet occasionally to 11 feet.
.SUNDAY...North gales to 40 knots becoming northwest 20 to
30 knots by mid afternoon. Showers through early afternoon, then
a chance of showers by mid afternoon. Waves building to 9 to
12 feet occasionally to 15 feet, then subsiding to 4 to 7 feet
occasionally to 9 feet.
.SUNDAY NIGHT...West winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Waves subsiding to calm to 2 feet.
.MONDAY...West winds 10 to 20 knots increasing to 15 to 25 knots.
A chance of showers. Waves building to 2 to 4 feet.
.TUESDAY...West winds 15 to 25 knots becoming southwest 10 to
20 knots. Waves subsiding to calm to 2 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-
355 PM EDT Thu Oct 12 2017

.LATE THIS AFTERNOON...South winds 15 to 25 knots. Waves 3 to
5 feet occasionally to 7 feet.
.TONIGHT...South winds 15 to 25 knots. A slight chance of drizzle
after midnight. Waves 3 to 5 feet occasionally to 7 feet.
.FRIDAY...Southwest winds 15 to 25 knots becoming west 10 to
20 knots in the afternoon, then increasing to 15 to 25 knots
late. A slight chance of showers through early afternoon. Waves
building to 3 to 6 feet occasionally to 8 feet.
.FRIDAY NIGHT...West winds 10 to 20 knots becoming northwest
15 to 25 knots after midnight, then becoming north 10 to 20 knots
late. Waves subsiding to 2 to 4 feet.
.SATURDAY...East winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. A slight chance of showers by mid
afternoon. Waves subsiding to calm to 2 feet, then building to
2 to 4 feet.
.SATURDAY NIGHT...East winds 15 to 25 knots becoming northeast
gales to 35 knots after midnight. Showers. Waves building to 6 to
9 feet occasionally to 11 feet.
.SUNDAY...North gales to 40 knots becoming northwest gales to
35 knots by mid afternoon. Showers through early afternoon, then
a chance of showers by mid afternoon. Waves building to 9 to
12 feet occasionally to 15 feet, then subsiding to 7 to 10 feet
occasionally to 13 feet.
.SUNDAY NIGHT...Northwest winds 15 to 25 knots becoming west
10 to 20 knots after midnight. Waves subsiding to 1 to 3 feet.
.MONDAY...West winds 15 to 25 knots increasing to 20 to 30 knots.
A chance of showers. Waves building to 4 to 7 feet occasionally
to 9 feet.
.TUESDAY...West winds 15 to 25 knots becoming southwest 10 to
20 knots. Waves subsiding to 1 to 3 feet.

$$

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

.LATE THIS AFTERNOON...Southeast winds 15 to 25 knots. Waves 2 to
4 feet.
.TONIGHT...Southeast winds 15 to 25 knots veering south after
midnight. A chance of drizzle. Waves subsiding to 1 to 3 feet,
then building to 2 to 4 feet.
.FRIDAY...Southwest winds 15 to 25 knots veering west late. A
slight chance of showers. Waves building to 3 to 5 feet
occasionally to 7 feet.
.FRIDAY NIGHT...West winds 15 to 25 knots veering northwest after
midnight, then diminishing to 10 to 20 knots late. Waves
subsiding to 2 to 4 feet.
.SATURDAY...East winds 10 to 20 knots. A slight chance of showers
by mid afternoon. Waves subsiding to calm to 2 feet, then
building to 1 to 3 feet.
.SATURDAY NIGHT...East winds 20 to 30 knots. Showers. Waves
building to 4 to 7 feet occasionally to 9 feet.
.SUNDAY...North gales to 40 knots. Showers through early
afternoon, then a chance of showers by mid afternoon. Waves
building to 8 to 11 feet occasionally to 14 feet, then subsiding
to 6 to 9 feet occasionally to 11 feet.
.SUNDAY NIGHT...Northwest winds 15 to 25 knots becoming west
10 to 20 knots after midnight. Waves subsiding to 1 to 3 feet.
.MONDAY...West winds 10 to 20 knots increasing to 15 to 25 knots.
A chance of showers. Waves building to 3 to 6 feet occasionally
to 8 feet.
.TUESDAY...West winds 20 to 30 knots becoming southwest 15 to
25 knots. Waves building to 4 to 7 feet occasionally to 9 feet,
then subsiding to 1 to 3 feet.

$$

LSZ261-130400-
MAFOR 1221/
Superior West 12410 11420 12520 11630 12620. Waves 1 to 5 feet.

Superior North Central 12420 11430 11420 11430 11530 12630. Waves
3 to 6 feet.

Superior South Central 14420 11420 11520 11620 11630. Waves 1 to
4 feet.

Superior East 12320 12420 13530 11630. 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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