Great Lakes Forecast
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FZUS63 KMQT 210817
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
317 AM EST Tue Nov 21 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 north of Lake Superior this
morning will move to western Quebec east of James Bay and weaken to
29.3 inches by this evening. A 30.5 inch high over the Northern
Plains this evening will drift south into the Central Plains
Wednesday morning and weaken to 30.2 inches over the Ohio Valley on
Wednesday night. On Thursday morning, a 29.9 inch trough will settle
south across the Upper Great Lakes. A 30.0 inch ridge will then move
over the Upper Great Lakes Thursday night and into the Lower Great
Lakes on Friday morning. A 29.0 inch low will move to Lake Winnipeg
Friday morning and track east across central and eastern Ontario
Friday evening while deepening to 28.9 inches. A 30.2 inch ridge
will move into the northern plains on Saturday.

LSZ162-211630-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
317 AM EST Tue Nov 21 2017 /217 AM CST Tue Nov 21 2017/

...GALE WARNING IN EFFECT THROUGH THIS AFTERNOON...

.EARLY THIS MORNING...West gales to 40 knots. Isolated snow
showers. Waves 7 to 10 feet occasionally to 13 feet.
.TODAY...Northwest gales to 35 knots diminishing to 20 to
30 knots by mid afternoon. Scattered snow showers. Waves
subsiding to 5 to 8 feet occasionally to 10 feet.
.TONIGHT...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots by midnight, then becoming west 10 to 20 knots late.
Isolated snow showers in the evening. Waves subsiding to 1 to
3 feet.
.WEDNESDAY...West winds 10 to 20 knots becoming southwest 15 to
25 knots. Waves building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots becoming west
10 to 20 knots after midnight. A chance of snow showers. Waves
subsiding to 1 to 3 feet.
.THURSDAY...West winds 10 to 20 knots diminishing to 5 to
15 knots in the afternoon. Waves subsiding to calm to 2 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots increasing to
15 to 25 knots after midnight. Waves building to 2 to 4 feet.
.FRIDAY...Southwest winds 20 to 30 knots becoming northwest gales
to 35 knots. A chance of rain showers. A chance of snow showers.
Waves building to 4 to 7 feet occasionally to 9 feet.
.SATURDAY...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots. A chance of snow showers. Waves subsiding to 1 to
3 feet.

$$

LSZ263-211630-
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-
317 AM EST Tue Nov 21 2017

...GALE WARNING IN EFFECT THROUGH THIS AFTERNOON...

.EARLY THIS MORNING...West gales to 40 knots. Isolated snow
showers. Waves 10 to 14 feet occasionally to 18 feet.
.TODAY...Northwest gales to 40 knots diminishing to 20 to
30 knots by mid afternoon. Scattered snow showers. Waves
subsiding to 6 to 9 feet occasionally to 11 feet.
.TONIGHT...Northwest winds 20 to 30 knots diminishing to 10 to
20 knots late. Isolated snow showers. Waves subsiding to 2 to
4 feet.
.WEDNESDAY...West winds 10 to 20 knots becoming southwest 15 to
25 knots by mid afternoon. A slight chance of snow showers in the
morning. Waves building to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots veering west
after midnight. A chance of snow showers. Waves subsiding to 3 to
5 feet occasionally to 7 feet.
.THURSDAY...Northwest winds 10 to 20 knots becoming west 5 to
15 knots in the afternoon. Waves subsiding to calm to 2 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots increasing to
15 to 25 knots after midnight. Waves building to 2 to 4 feet.
.FRIDAY...Southwest winds 20 to 30 knots becoming northwest gales
to 35 knots. A chance of rain showers. A chance of snow showers.
Waves building to 5 to 9 feet occasionally to 11 feet.
.SATURDAY...Northwest winds 20 to 30 knots becoming north 15 to
25 knots. A chance of snow showers. Waves subsiding to 2 to
4 feet.

$$

LSZ264-211630-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
317 AM EST Tue Nov 21 2017

...GALE WARNING IN EFFECT THROUGH THIS EVENING...

.EARLY THIS MORNING...West gales to 35 knots. Scattered snow
showers, possibly mixed with rain. Waves 10 to 14 feet
occasionally to 18 feet.
.TODAY...Northwest gales to 45 knots. Scattered snow showers.
Waves subsiding to 7 to 10 feet occasionally to 13 feet.
.TONIGHT...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots late. Scattered snow showers. Waves subsiding to 3 to
6 feet occasionally to 8 feet.
.WEDNESDAY...West winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. A slight chance of snow showers. Waves
subsiding to 2 to 4 feet, then building to 3 to 6 feet
occasionally to 8 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots veering west
after midnight. A chance of snow showers. Waves building to 4 to
7 feet occasionally to 9 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.THURSDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon. Waves subsiding to 1 to 3 feet.
.THURSDAY NIGHT...South winds 5 to 15 knots increasing to 15 to
25 knots after midnight. A chance of snow showers. A chance of
rain showers after midnight. Waves subsiding to calm to 2 feet,
then building to 2 to 4 feet.
.FRIDAY...Southwest winds 20 to 30 knots becoming northwest gales
to 35 knots. Rain showers likely, then a chance of rain showers,
possibly mixed with snow. Waves building to 7 to 10 feet
occasionally to 13 feet.
.SATURDAY...Northwest gales to 35 knots becoming north 15 to
25 knots. A chance of snow showers. Waves building to 8 to
11 feet occasionally to 14 feet, then subsiding to 3 to 5 feet
occasionally to 7 feet.

$$

LSZ265-211630-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
317 AM EST Tue Nov 21 2017

...GALE WARNING IN EFFECT THROUGH THIS EVENING...

.EARLY THIS MORNING...West gales to 35 knots. Scattered snow
showers, possibly mixed with rain. Waves 5 to 9 feet occasionally
to 11 feet.
.TODAY...West gales to 40 knots veering northwest. Scattered snow
showers in the morning, then numerous snow showers in the
afternoon. Waves building to 10 to 14 feet occasionally to
18 feet, then subsiding to 8 to 11 feet occasionally to 14 feet.
.TONIGHT...Northwest gales to 35 knots diminishing to 20 to
30 knots by midnight. Scattered snow showers. Waves subsiding to
3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...West winds 15 to 25 knots backing southwest by mid
afternoon. A slight chance of snow showers in the morning. Waves
subsiding to 1 to 3 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots veering west
after midnight. A slight chance of snow showers. Waves building
to 2 to 4 feet.
.THURSDAY...West winds 20 to 30 knots becoming northwest 15 to
25 knots in the afternoon. Waves subsiding to 1 to 3 feet.
.THURSDAY NIGHT...Southwest winds 10 to 20 knots becoming south
15 to 25 knots after midnight. Waves subsiding to calm to 2 feet,
then building to 1 to 3 feet.
.FRIDAY...Southwest winds 20 to 30 knots becoming west gales to
35 knots. Rain showers likely, then a chance of rain showers,
possibly mixed with snow. Waves building to 2 to 4 feet, then
subsiding to 1 to 3 feet.
.SATURDAY...Northwest gales to 35 knots diminishing to 20 to
30 knots. Snow showers likely, then a chance of snow showers.
Waves building to 8 to 11 feet occasionally to 14 feet, then
subsiding to 3 to 6 feet occasionally to 8 feet.

$$

LSZ266-211630-
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-
317 AM EST Tue Nov 21 2017

...GALE WARNING IN EFFECT THROUGH THIS EVENING...

.EARLY THIS MORNING...West gales to 35 knots. Scattered rain
showers, possibly mixed with snow. Waves 8 to 11 feet
occasionally to 14 feet building to 9 to 12 feet occasionally to
15 feet.
.TODAY...West gales to 40 knots becoming northwest gales to
45 knots. Numerous rain showers in the morning. Numerous snow
showers. Waves building to 12 to 17 feet occasionally to 21 feet,
then subsiding to 11 to 15 feet occasionally to 19 feet.
.TONIGHT...Northwest gales to 40 knots diminishing to 20 to
30 knots late. Scattered snow showers. Waves subsiding to 5 to
8 feet occasionally to 10 feet.
.WEDNESDAY...West winds 15 to 25 knots backing southwest by mid
afternoon. A chance of snow showers. Waves subsiding to 3 to
6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots veering west
after midnight. A chance of snow showers. Waves building to 4 to
7 feet occasionally to 9 feet.
.THURSDAY...West winds 20 to 30 knots becoming northwest 15 to
25 knots in the afternoon. A chance of snow showers. Waves
subsiding to 3 to 6 feet occasionally to 8 feet, then building to
4 to 7 feet occasionally to 9 feet.
.THURSDAY NIGHT...Northwest winds 10 to 20 knots becoming south
15 to 25 knots after midnight. A chance of snow showers. Waves
subsiding to 1 to 3 feet, then building to 2 to 4 feet.
.FRIDAY...South winds 20 to 30 knots becoming west gales to
35 knots. Rain showers likely, then a chance of rain showers,
possibly mixed with snow. Waves building to 9 to 12 feet
occasionally to 15 feet.
.SATURDAY...Northwest gales to 40 knots becoming north 20 to
30 knots. Snow showers likely. Waves building to 10 to 14 feet
occasionally to 18 feet, then subsiding to 4 to 7 feet
occasionally to 9 feet.

$$

LSZ267-211630-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
317 AM EST Tue Nov 21 2017

...GALE WARNING IN EFFECT THROUGH THIS EVENING...

.EARLY THIS MORNING...West gales to 35 knots. Scattered rain
showers. Waves 4 to 7 feet occasionally to 9 feet building to
6 to 9 feet occasionally to 11 feet.
.TODAY...West gales to 35 knots becoming northwest gales to
45 knots. Numerous rain showers in the morning. Numerous snow
showers. Waves building to 12 to 17 feet occasionally to 21 feet,
then subsiding to 11 to 15 feet occasionally to 19 feet.
.TONIGHT...Northwest gales to 35 knots diminishing to 15 to
25 knots. Numerous snow showers in the evening, then scattered
snow showers after midnight. Waves subsiding to 5 to 8 feet
occasionally to 10 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots backing west. A
chance of snow showers. Waves subsiding to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY NIGHT...Southwest winds 20 to 30 knots. A chance of
snow showers. Waves building to 3 to 6 feet occasionally to
8 feet.
.THURSDAY...West winds 20 to 30 knots veering northwest in the
afternoon. A chance of snow showers, possibly mixed with rain.
Waves building to 4 to 7 feet occasionally to 9 feet, then
subsiding to 3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...West winds 10 to 20 knots becoming south 15 to
25 knots after midnight. A chance of snow showers. Waves
subsiding to 1 to 3 feet, then building to 2 to 4 feet.
.FRIDAY...South gales to 35 knots veering west. Rain showers
likely. A chance of snow showers. A chance of rain showers. Waves
building to 9 to 12 feet occasionally to 15 feet.
.SATURDAY...Northwest gales to 35 knots becoming north 20 to
30 knots. Snow showers likely, then a chance of snow showers.
Waves building to 10 to 14 feet occasionally to 18 feet, then
subsiding to 3 to 6 feet occasionally to 8 feet.

$$

LSZ261-211630-
MAFOR 2110/
Superior West...Gale Warning in effect...14750 11750 11740 12730.
Scattered snow showers through early afternoon today. Waves 9 to
12 feet subsiding to 5 to 8 feet today. Waves 5 to 8 feet
subsiding to 3 to 6 feet tonight.

Superior North Central...Gale Warning in effect...11657 12760
12750 12740 11730. Scattered rain and snow showers early this
morning. Scattered snow showers from late morning on today.
Scattered snow showers through early evening tonight. Waves 9 to
13 feet today. Waves 6 to 10 feet subsiding to 5 to 8 feet
tonight.

Superior South Central...Gale Warning in effect...11650 11757
11767 12757 12740 11730. Scattered snow and rain showers through
mid morning. Scattered snow showers from late evening on tonight.
Waves 6 to 9 feet building to 11 to 15 feet today. Waves 10 to 13
feet subsiding to 5 to 9 feet tonight.

Superior East...Gale Warning in effect...12657 11767 12757 11750
11740 11730. Scattered snow showers from late evening on tonight.
Waves 5 to 8 feet building to 11 to 16 feet today. Waves 10 to 14
feet subsiding to 6 to 10 feet tonight.

$$

07

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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