Great Lakes Forecast
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357
FZUS63 KMQT 210304
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1004 PM EST Mon Nov 20 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 29.2 inch low pressure over northwestern Ontario
will deepen to 29.1 inches as it moves north of Lake Superior
overnight and reaches James Bay by Tuesday afternoon. A 30.4 inch
high over the Northern Plains Tuesday evening will drift south
into the Central Plains Wednesday morning and weaken to 30.3
inches over the Ohio Valley on Wednesday night. On Thursday
morning, a 29.8 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 northern Ontario Friday evening. This low
will drag a 29.2 inch trough across Lake Superior on late Friday
night. A 30.0 inch ridge then builds into the Upper Great Lakes on
Saturday.

LSZ162-211115-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1004 PM EST Mon Nov 20 2017 /904 PM CST Mon Nov 20 2017/

...GALE WARNING IN EFFECT THROUGH TUESDAY AFTERNOON...

.REST OF TONIGHT...Southwest winds 20 to 30 knots becoming west
gales to 40 knots. Isolated snow showers. Waves 3 to 5 feet
occasionally to 7 feet building to 7 to 10 feet occasionally to 13
feet.
.TUESDAY...Northwest gales to 40 knots diminishing to 20 to
30 knots by mid afternoon. Scattered snow showers. Waves
subsiding to 4 to 7 feet occasionally to 9 feet.
.TUESDAY NIGHT...Northwest winds 20 to 30 knots diminishing to
15 to 25 knots by midnight, then backing west late. A slight
chance of snow showers in the evening. Waves subsiding to 1 to
3 feet.
.WEDNESDAY...West winds 10 to 20 knots backing southwest in the
afternoon. Waves building to 2 to 4 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots becoming west
10 to 20 knots after midnight. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 2 to 4 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...West winds 5 to 15 knots becoming south 15 to
25 knots after midnight. Waves building to 1 to 3 feet.
.FRIDAY...Southwest winds 20 to 30 knots with a few gale force
gusts to 35 knots turning west late. A chance of rain showers,
possibly mixed with snow. Waves building to 3 to 6 feet
occasionally to 8 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.

$$

LSZ263-211115-
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-
1004 PM EST Mon Nov 20 2017

...GALE WARNING IN EFFECT THROUGH TUESDAY AFTERNOON...

.REST OF TONIGHT...Southwest winds 20 to 30 knots becoming west
gales to 45 knots. Isolated rain and snow showers. Waves 3 to 5
feet occasionally to 7 feet building to 10 to 14 feet occasionally
to 18 feet.
.TUESDAY...Northwest gales to 45 knots diminishing to 20 to 30
knots by mid afternoon. Scattered snow showers. Waves subsiding to
5 to 8 feet occasionally to 10 feet.
.TUESDAY NIGHT...Northwest winds 20 to 30 knots diminishing to
10 to 20 knots. A slight chance of snow showers. Waves subsiding
to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...West winds 10 to 20 knots. Waves subsiding to 2 to
4 feet, then building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY NIGHT...West winds 15 to 25 knots. Waves building to
3 to 6 feet occasionally to 8 feet.
.THURSDAY...West winds 10 to 20 knots veering northwest in the
afternoon. Waves subsiding to 1 to 3 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 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 with a few gale force
gusts to 35 knots becoming west late. A chance of rain showers,
possibly mixed with snow. Waves building to 4 to 8 feet
occasionally to 10 feet.
.SATURDAY...North winds 20 to 30 knots becoming northwest 15 to
25 knots. A chance of snow showers. Waves subsiding to 1 to
3 feet.

$$

LSZ264-211115-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1004 PM EST Mon Nov 20 2017

...GALE WARNING IN EFFECT THROUGH TUESDAY EVENING...

.REST OF TONIGHT...Southwest winds 20 to 30 knots becoming west
gales to 40 knots. Scattered snow showers, possibly mixed with
rain. Waves 4 to 7 feet occasionally to 9 feet building to 10 to
14 feet occasionally to 18 feet.
.TUESDAY...Northwest gales to 40 knots increasing to 45 knots.
Scattered snow showers. Waves subsiding to 8 to 11 feet
occasionally to 14 feet.
.TUESDAY NIGHT...Northwest gales 40 knots diminishing to 15 to 25
knots by midnight. A chance of snow showers. Waves subsiding to 3
to 6 feet occasionally to 8 feet.
.WEDNESDAY...West winds 15 to 25 knots. A slight chance of snow
showers in the morning. Waves subsiding to 2 to 4 feet, then
building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY NIGHT...West winds 15 to 25 knots. A chance of
freezing rain after midnight. Waves building to 4 to 7 feet
occasionally to 9 feet.
.THURSDAY...Northwest winds 15 to 25 knots. Waves subsiding to
2 to 4 feet.
.THURSDAY NIGHT...Northwest winds 5 to 15 knots becoming south
20 to 30 knots after midnight. Snow showers likely after
midnight. Waves subsiding to calm to 2 feet, then building to
1 to 3 feet.
.FRIDAY...Southwest winds 20 to 30 knots with a few gale force
gusts to 35 knots becoming west late. A chance of rain showers,
possibly mixed with snow. Waves building to 7 to 10 feet
occasionally to 13 feet.
.SATURDAY...North gales to 35 knots becoming northwest 20 to
30 knots. A chance of snow showers. Waves subsiding to 3 to
5 feet occasionally to 7 feet.

$$

LSZ265-211115-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1004 PM EST Mon Nov 20 2017

...GALE WARNING IN EFFECT FROM 4 AM EST TUESDAY THROUGH TUESDAY
EVENING...

.REST OF TONIGHT...Southwest winds 15 to 25 knots becoming west
gales to 40 knots. Scattered snow showers, possibly mixed with
rain. Waves 3 to 6 feet occasionally to 8 feet, then building to
6 to 9 feet occasionally to 11 feet.
.TUESDAY...West gales 45 knots becoming northwest by late
morning. Numerous snow showers. Waves building to 10 to 14 feet
occasionally to 18 feet, then subsiding to 8 to 11 feet
occasionally to 14 feet.
.TUESDAY NIGHT...Northwest gales to 35 knots diminishing to 20 to
30 knots by midnight. A chance of snow showers. Waves subsiding
to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon. A slight chance of snow showers in the
morning. Waves subsiding to 1 to 3 feet.
.WEDNESDAY NIGHT...West winds 15 to 25 knots increasing to 20 to
30 knots after midnight. Waves building to 2 to 4 feet.
.THURSDAY...West winds 20 to 30 knots becoming northwest 15 to
25 knots in the afternoon. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 2 to 4 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 calm to 2 feet, then building to 1 to 3 feet.
.FRIDAY...Southwest winds 20 to 30 knots with a few gale force
gusts to 35 knots becoming west late. A chance of rain showers,
possibly mixed with snow. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 2 to 4 feet.
.SATURDAY...Northwest gales to 35 knots diminishing to 20 to
30 knots. Snow showers likely. Waves building to 7 to 10 feet
occasionally to 13 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.

$$

LSZ266-211115-
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-
1004 PM EST Mon Nov 20 2017

...GALE WARNING IN EFFECT FROM 4 AM EST TUESDAY THROUGH TUESDAY
EVENING...

.REST OF TONIGHT...South winds 20 to 30 knots becoming west gales
to 40 knots. Scattered rain showers, possibly mixed with snow
after midnight. Waves 4 to 8 feet occasionally to 10 feet, then
building to 9 to 12 feet occasionally to 15 feet.
.TUESDAY...West gales 45 knots becoming northwest by late
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.
.TUESDAY NIGHT...Northwest gales to 40 knots diminishing to 20 to
30 knots late. A chance of snow showers. Waves subsiding to 5 to
8 feet occasionally to 10 feet.
.WEDNESDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon. A slight chance of snow showers. Waves
subsiding to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots veering west
after midnight. A chance of rain and 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 rain showers and freezing
rain in the morning. A chance of snow showers. Waves subsiding to
3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...Northwest winds 10 to 20 knots becoming south
20 to 30 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 with a few gale force gusts
to 35 knots turning west late. A chance of rain showers, possibly
mixed with snow. Waves building to 8 to 11 feet occasionally to
14 feet.
.SATURDAY...North gales to 35 knots diminishing to 20 to 30
knots. Snow showers likely. Waves building to 9 to 12 feet
occasionally to 15 feet, then subsiding to 4 to 7 feet
occasionally to 9 feet.

$$

LSZ267-211115-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1004 PM EST Mon Nov 20 2017

...GALE WARNING IN EFFECT FROM 6 AM EST TUESDAY THROUGH TUESDAY
EVENING...

.REST OF TONIGHT...South winds 20 to 30 knots veering southwest
late. Scattered rain showers. Waves 4 to 7 feet occasionally to 9
feet building to 6 to 9 feet occasionally to 11 feet.
.TUESDAY...West gales to 40 knots becoming northwest gales to
45 knots. Numerous rain and snow 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...Northwest gales to 35 knots diminishing to 20 to
30 knots by midnight. A chance of snow showers. Waves subsiding
to 5 to 8 feet occasionally to 10 feet.
.WEDNESDAY...West winds 15 to 25 knots. A chance of snow showers.
Waves subsiding to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots veering west
after midnight. 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 freezing rain, rain, and snow. Waves
building to 4 to 7 feet occasionally to 9 feet, then subsiding to
3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...Northwest winds 10 to 20 knots becoming west
15 to 25 knots after midnight. A chance of snow showers. Waves
subsiding to 1 to 3 feet.
.FRIDAY...South winds 20 to 30 knots with a few gale force gusts
to 35 knots turning west late. Rain and snow showers. Waves
building to 9 to 12 feet occasionally to 15 feet.
.SATURDAY...North gales to 35 knots diminishing to 20 to 30
knots. Snow showers likely. Waves subsiding to 4 to 7 feet
occasionally to 9 feet.

$$
LSZ261-211115-
MAFOR 2104/
Superior West...Gale Warning in effect...11650 11660 11760 13750
12740. Scattered snow showers Tuesday morning. Waves 5 to 9 feet
building to 9 to 12 feet overnight, then subsiding to 4 to 7 feet
Tuesday evening.

Superior North Central...Gale Warning in effect...11550 11650
11657 11767 11760 13750. Scattered snow showers. Waves 3 to 6
feet building to 9 to 13 feet overnight, then subsiding to 6 to
10 feet Tuesday evening.

Superior South Central...Gale Warning in effect...11540 11650
11660 13767 11757 11750. Scattered snow showers. Waves 3 to 6
feet building to 6 to 9 feet overnight. Waves then building to
11 to 15 feet Tuesday, and subsiding to 8 to 11 feet Tuesday
evening.

Superior East...Gale Warning in effect...12540 11650 11657 13757
11750. Scattered rain and snow showers. Waves 5 to 8 feet
overnight building to 10 to 15 feet Tuesday.


$$

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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