Great Lakes Forecast
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578
FZUS63 KMQT 251510
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1010 AM EST Sun Feb 25 2018

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...Low pressure of 29.1 inches north of Lake Superior
will lift northeast to James Bay this afternoon. A high pressure
ridge of 30.1 inches across the central Mississippi River Valley
today will build across the Ohio Valley at 30.3 inches on Monday.
Meanwhile a 29.6 inch low crossing southern Manitoba on Monday
will weaken to 29.8 inches as it crosses northern Ontario Tuesday.
A 30.1 inch ridge arrives over the Upper Great Lakes on Wednesday
then on Thursday a 29.1 inch low will track across the Great
Lakes region.

LSZ162-252315-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1010 AM EST Sun Feb 25 2018 /910 AM CST Sun Feb 25 2018/

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

.REST OF TODAY...West gales to 40 knots. A slight chance of snow
late in the morning.
.TONIGHT...West winds 20 to 30 knots becoming southwest 15 to
25 knots by midnight, then diminishing to 10 to 20 knots late.
.MONDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots by late morning, then diminishing to 5 to 15 knots by
mid afternoon.
.MONDAY NIGHT...Southwest winds 5 to 15 knots increasing to 10 to
20 knots after midnight.
.TUESDAY...West winds 5 to 15 knots.
.TUESDAY NIGHT...West winds less than 10 knots veering north
after midnight.
.WEDNESDAY...East winds 5 to 15 knots becoming northeast 10 to
20 knots.
.THURSDAY...Northeast winds 15 to 25 knots diminishing to 10 to
20 knots.

Note, waves omitted for mostly ice covered areas.

$$

LSZ263-252315-
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-
1010 AM EST Sun Feb 25 2018

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

.REST OF TODAY...West gales to 40 knots with a few storm force
gusts to 55 knots by late morning, then diminishing to gales to
45 knots by mid afternoon. A slight chance of snow late in the
morning.
.TONIGHT...West gales to 35 knots diminishing to 15 to 25 knots
by midnight, then becoming southwest 10 to 20 knots late.
.MONDAY...Southwest winds 10 to 20 knots.
.MONDAY NIGHT...South winds 5 to 15 knots becoming southwest
10 to 20 knots after midnight.
.TUESDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots
in the afternoon.
.TUESDAY NIGHT...West winds less than 10 knots veering north
after midnight.
.WEDNESDAY...East winds 5 to 15 knots increasing to 10 to
20 knots.
.THURSDAY...Northeast winds 15 to 25 knots becoming north 10 to
20 knots.

Note, waves omitted for mostly ice covered areas.

$$

LSZ264-252315-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1010 AM EST Sun Feb 25 2018

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

.REST OF TODAY...West gales to 45 knots with a few storm force
gusts to 55 knots. A chance of snow late in the morning.
.TONIGHT...West gales to 40 knots diminishing to 15 to 25 knots.
.MONDAY...Southwest winds 15 to 25 knots becoming south 10 to
20 knots by mid afternoon.
.MONDAY NIGHT...South winds 10 to 20 knots becoming southwest
15 to 25 knots after midnight.
.TUESDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon.
.TUESDAY NIGHT...West winds 5 to 15 knots veering northwest after
midnight.
.WEDNESDAY...Northeast winds 5 to 15 knots becoming east 10 to
20 knots.
.THURSDAY...Northeast winds 15 to 25 knots backing north.

Note, waves omitted for mostly ice covered areas.

$$

LSZ265-252315-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1010 AM EST Sun Feb 25 2018

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

.REST OF TODAY...West gales to 45 knots. A slight chance of snow
late in the morning.
.TONIGHT...West winds 20 to 30 knots diminishing to 15 to
25 knots by midnight.
.MONDAY...Southwest winds 10 to 20 knots backing south.
.MONDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight.
.TUESDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots
in the afternoon.
.TUESDAY NIGHT...West winds 5 to 15 knots veering north after
midnight.
.WEDNESDAY...Northeast winds 5 to 15 knots becoming east 10 to
20 knots.
.THURSDAY...Northeast winds 15 to 25 knots backing north.

Note, waves omitted for mostly ice covered areas.

$$

LSZ266-252315-
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-
1010 AM EST Sun Feb 25 2018

...GALE WARNING IN EFFECT THROUGH LATE TONIGHT...

.REST OF TODAY...Southwest gales to 45 knots with a few west
storm force winds to 50 knots by late morning, then diminishing to
gales to 45 knots by mid afternoon. A slight chance of snow late
in the morning. Waves 4 to 7 feet occasionally to 9 feet building
to 9 to 12 feet occasionally to 15 feet, then subsiding to 8 to 11
feet occasionally to 14 feet.
.TONIGHT...West gales to 40 knots diminishing to 20 to 30 knots
by midnight. Waves subsiding to 3 to 6 feet occasionally to
8 feet.
.MONDAY...West winds 15 to 25 knots becoming southwest 10 to
20 knots by late morning, then backing south by mid afternoon. A
slight chance of snow in the morning. Waves subsiding to calm to
2 feet, then building to 1 to 3 feet.
.MONDAY NIGHT...South winds 15 to 25 knots becoming southwest
10 to 20 knots after midnight. Waves building to 2 to 4 feet,
then subsiding to 1 to 3 feet.
.TUESDAY...Southwest winds 10 to 20 knots becoming west 5 to
15 knots in the afternoon. Waves subsiding to calm to 2 feet.
.TUESDAY NIGHT...Northwest winds 5 to 15 knots veering north
after midnight. Waves calm to 2 feet.
.WEDNESDAY...Northeast winds 5 to 15 knots becoming east 10 to
20 knots. Waves building to 2 to 4 feet.
.THURSDAY...Northeast winds 20 to 30 knots. Waves building to
3 to 5 feet occasionally to 7 feet, then subsiding to 2 to
4 feet.

Note, wave height forecasts are for ice free areas.

$$

LSZ267-252315-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1010 AM EST Sun Feb 25 2018

...GALE WARNING IN EFFECT THROUGH LATE TONIGHT...

.REST OF TODAY...Southwest gales to 40 knots. A chance of drizzle
and a slight chance of snow late in the morning. Waves 4 to
7 feet occasionally to 9 feet building to 8 to 11 feet
occasionally to 14 feet.
.TONIGHT...West gales to 35 knots diminishing to 20 to 30 knots
by midnight. A slight chance of snow after midnight. Waves
subsiding to 3 to 6 feet occasionally to 8 feet.
.MONDAY...West winds 15 to 25 knots becoming southwest 10 to
20 knots by late morning, then backing south by mid afternoon. A
slight chance of snow, possibly mixed with freezing rain in the
morning. Waves subsiding to calm to 2 feet.
.MONDAY NIGHT...South winds 15 to 25 knots veering southwest
after midnight. Waves building to 2 to 4 feet, then subsiding to
1 to 3 feet.
.TUESDAY...Southwest winds 15 to 25 knots becoming west 10 to
20 knots in the afternoon. Waves subsiding to calm to 2 feet.
.TUESDAY NIGHT...Northwest winds 5 to 15 knots veering north
after midnight. Waves calm to 2 feet.
.WEDNESDAY...Northeast winds 5 to 15 knots becoming east 10 to
20 knots. Waves building to 1 to 3 feet.
.THURSDAY...Northeast winds 20 to 30 knots. Waves building to
2 to 4 feet, then subsiding to 1 to 3 feet.

Note, wave height forecasts are for ice free areas.

$$
LSZ261-252315-
MAFOR 2516/
Superior West...Gale Warning in effect...12660 11650 12640 11530
12520. Waves omitted for mostly ice covered areas.

Superior North Central...Gale Warning in effect...13660 11650
11640 11630 11620 11520. Waves omitted for mostly ice covered
areas.

Superior South Central...Gale Warning in effect...12660 11650
11640 12630 11620 11520. Waves omitted for mostly ice covered
areas.

Superior East...Gale Warning in effect...11560 11660 13650 12640
11630. Waves 5 to 8 feet building to 8 to 12 feet this afternoon.
Waves 7 to 11 feet subsiding to 5 to 9 feet tonight. Waves 4 to 7
feet subsiding to 3 to 5 feet Monday morning.

$$

JSS

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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