Great Lakes Forecast
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000
FZUS63 KMQT 201500
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1000 AM EST Tue Feb 20 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...A trough of 29.9 inches will push slowly
northeastward through the Western Great Lakes today, reaching
Quebec on Wednesday. A high pressure system of 30.6 inches will
then push towards the Great Lakes Wednesday afternoon and drift
into southern Quebec Thursday. A weak 30.1 inch trough will pass
across the western Great Lakes on Friday followed by weak a ridge
of 30.3 inches on Saturday.

LSZ162-202300-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1000 AM EST Tue Feb 20 2018 /900 AM CST Tue Feb 20 2018/

.REST OF TODAY...Northeast winds 20 to 30 knots diminishing to
15 to 25 knots by late morning, then becoming northwest 5 to
15 knots by mid afternoon. Patchy blowing snow late in the
morning. Snow showers, possibly mixed with freezing rain late in
the morning, then a chance of snow showers and a slight chance of
freezing drizzle in the afternoon.
.TONIGHT...West winds 10 to 20 knots. Isolated snow showers.
.WEDNESDAY...West winds 10 to 20 knots backing southwest by mid
afternoon.
.WEDNESDAY NIGHT...Southwest winds 10 to 20 knots diminishing to
5 to 15 knots after midnight.
.THURSDAY...South winds less than 10 knots increasing to 5 to
15 knots in the afternoon.
.THURSDAY NIGHT...Southeast winds 5 to 15 knots veering south
after midnight. A chance of snow showers in the evening, then
snow showers likely after midnight.
.FRIDAY...West winds 5 to 15 knots. A chance of snow showers.
.SATURDAY...South winds 5 to 15 knots backing east. A chance of
snow showers.

Note, waves omitted for mostly ice covered areas.

$$

LSZ263-202300-
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-
1000 AM EST Tue Feb 20 2018

.REST OF TODAY...Northeast winds 20 to 30 knots diminishing to
15 to 25 knots by late morning, then becoming north 10 to
20 knots by mid afternoon. Areas of blowing snow late in the
morning. Snow showers likely, possibly mixed with freezing rain
late in the morning, then a chance of snow showers and a slight
chance of freezing drizzle in the afternoon.
.TONIGHT...Northwest winds 10 to 20 knots backing west late.
Isolated snow showers.
.WEDNESDAY...West winds 10 to 20 knots backing southwest by mid
afternoon. A slight chance of snow showers in the morning. Patchy
blowing snow in the afternoon.
.WEDNESDAY NIGHT...Southwest winds 10 to 20 knots diminishing to
5 to 15 knots after midnight.
.THURSDAY...South winds less than 10 knots increasing to 5 to
15 knots in the afternoon.
.THURSDAY NIGHT...Southeast winds 5 to 15 knots veering south
after midnight. A chance of snow showers.
.FRIDAY...West winds 5 to 15 knots. A chance of snow showers.
.SATURDAY...Southeast winds 5 to 15 knots backing east. A chance
of snow showers.

Note, waves omitted for mostly ice covered areas.

$$

LSZ264-202300-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1000 AM EST Tue Feb 20 2018

.REST OF TODAY...Northeast winds 15 to 25 knots diminishing to
10 to 20 knots by late morning, then backing north by mid
afternoon. Patchy blowing snow late in the morning. Snow showers
likely, possibly mixed with freezing rain late in the morning,
then a chance of snow showers and a slight chance of freezing
drizzle in the afternoon.
.TONIGHT...Northwest winds 10 to 20 knots. Isolated snow showers.
.WEDNESDAY...West winds 5 to 15 knots increasing to 10 to
20 knots by late morning, then becoming southwest 15 to 25 knots
by mid afternoon. A slight chance of snow showers in the morning.
Patchy blowing snow in the afternoon.
.WEDNESDAY NIGHT...Southwest winds 10 to 20 knots.
.THURSDAY...Southwest winds less than 10 knots becoming south
5 to 15 knots in the afternoon.
.THURSDAY NIGHT...South winds 5 to 15 knots. A chance of snow
showers.
.FRIDAY...West winds 5 to 15 knots. A chance of snow showers.
.SATURDAY...Southeast winds 5 to 15 knots backing east. A chance
of snow showers.

Note, waves omitted for mostly ice covered areas.

$$

LSZ265-202300-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1000 AM EST Tue Feb 20 2018

.REST OF TODAY...East winds 10 to 20 knots diminishing to 5 to
15 knots by late morning, then backing northwest by mid
afternoon. A chance of freezing rain, possibly mixed with snow
showers late in the morning. A chance of freezing drizzle.
.TONIGHT...Northwest winds 15 to 25 knots.
.WEDNESDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon.
.WEDNESDAY NIGHT...Southwest winds 10 to 20 knots diminishing to
5 to 15 knots after midnight.
.THURSDAY...Southwest winds 5 to 15 knots backing southeast in
the afternoon.
.THURSDAY NIGHT...Southeast winds 10 to 20 knots diminishing to
5 to 15 knots after midnight. A chance of snow showers.
.FRIDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots.
A chance of freezing rain. A chance of snow showers.
.SATURDAY...East winds 5 to 15 knots. Snow showers likely.

Note, waves omitted for mostly ice covered areas.

$$

LSZ266-202300-
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-
1000 AM EST Tue Feb 20 2018

.REST OF TODAY...East winds 15 to 25 knots diminishing to 10 to
20 knots by late morning, then becoming west 5 to 15 knots by mid
afternoon. Freezing spray late in the morning. Freezing rain
likely late in the morning. A slight chance of freezing drizzle
and snow showers. Waves 6 to 9 feet occasionally to 11 feet
subsiding to 1 to 3 feet.
.TONIGHT...Northwest winds 15 to 25 knots increasing to 20 to
30 knots by midnight. Waves building to 4 to 7 feet occasionally
to 9 feet, then subsiding to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots. A slight chance of snow showers in the morning. Waves
subsiding to 1 to 3 feet.
.WEDNESDAY NIGHT...Southwest winds 10 to 20 knots diminishing to
5 to 15 knots after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...Southwest winds 5 to 15 knots backing south in the
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...South winds 10 to 20 knots. A chance of snow
showers. Waves calm to 2 feet.
.FRIDAY...Southwest winds 10 to 20 knots becoming northwest 5 to
15 knots. Snow showers likely. Waves building to 1 to 3 feet,
then subsiding to calm to 2 feet.
.SATURDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots. Snow showers likely. Waves building to 1 to 3 feet.

Note, wave height forecasts are for ice free areas.

$$

LSZ267-202300-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1000 AM EST Tue Feb 20 2018

.REST OF TODAY...East winds 15 to 25 knots becoming southeast
10 to 20 knots by late morning, then becoming southwest 5 to
15 knots by mid afternoon. Freezing drizzle likely, possibly
mixed with snow showers and sleet late in the morning, then a
chance of freezing drizzle in the afternoon. Waves 3 to 6 feet
occasionally to 8 feet subsiding to calm to 2 feet.
.TONIGHT...West winds 15 to 25 knots becoming northwest 20 to
30 knots by midnight. Patchy freezing drizzle in the evening.
Isolated snow showers after midnight. Heavy freezing spray and
patchy blowing snow after midnight. Waves building to 4 to 7 feet
occasionally to 9 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots backing west by late
morning, then diminishing to 10 to 20 knots by mid afternoon.
Heavy freezing spray in the morning. A slight chance of snow
showers. Waves subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots becoming southwest
5 to 15 knots after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...Southwest winds 5 to 15 knots backing south in the
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 10 to 20 knots. A chance of
snow showers. Waves calm to 2 feet.
.FRIDAY...South winds 10 to 20 knots becoming northwest 5 to
15 knots. Freezing rain, possibly mixed with snow showers, then a
chance of snow showers, possibly mixed with freezing rain. Waves
building to 1 to 3 feet, then subsiding to calm to 2 feet.
.SATURDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots. Snow showers likely. Waves building to 1 to 3 feet.

Note, wave height forecasts are for ice free areas.

$$
LSZ261-202300-
MAFOR 2016/
Superior West 11147 11820 11720 11630 11720 13620. Chance of snow
showers late this afternoon. Waves omitted for mostly ice covered
areas.

Superior North Central 11137 11120 11820 11720 12730 11720 11620.
Chance of light freezing rain, then chance of snow showers late
late this morning. Waves omitted for mostly ice covered areas.

Superior South Central 11310 11610 14720 11720 11620. Chance of
light freezing drizzle and light freezing rain late this morning
through early this afternoon. Waves omitted for mostly ice
covered areas.

Superior East 11231 11410 11620 11640 13742 11732. Freezing spray
late this morning. Chance of light freezing rain and light
freezing drizzle late this morning through late this afternoon.
Freezing spray late this evening then heavy freezing spray after
midnight tonight. Waves 4 to 7 feet subsiding to 2 to 4 feet this
afternoon. Waves 1 to 3 feet building to 3 to 7 feet tonight and
Wednesday 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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