Great Lakes Forecast
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FZUS63 KMQT 181451
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
951 AM EST Sun Feb 18 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 30.1 inch ridge has begun to push east of Lake
Superior late this morning. A trough of 29.7 inches will move
into the Upper Great Lakes this evening and weaken to 29.9 inches
late tonight, and a 30.5 inch high pressure will then move across
northern Ontario Monday. Secondary troughing of 29.8 inches will
push northeastward into the Western Great Lakes into Tuesday
morning and remain in the area through Wednesday morning. A high
pressure system of 30.6 inches will reach the Great Lakes
Wednesday afternoon and slowly shift into southern Quebec through
the day Thursday.

LSZ162-182300-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
951 AM EST Sun Feb 18 2018 /851 AM CST Sun Feb 18 2018/

.REST OF TODAY...Southeast winds 5 to 15 knots becoming east
10 to 20 knots by late morning, then increasing to 15 to 25 knots
by mid afternoon. A chance of snow showers late in the morning,
then snow showers in the afternoon. Patchy blowing snow in the
afternoon.
.TONIGHT...Northeast winds 15 to 25 knots backing north by
midnight, then becoming northeast 10 to 20 knots late. Patchy
blowing snow. Snow showers likely in the evening. A slight chance
of snow showers after midnight.
.MONDAY...Northeast winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. Areas of blowing snow. A chance of
snow showers.
.MONDAY NIGHT...Northeast winds 20 to 30 knots diminishing to
15 to 25 knots after midnight. Areas of blowing snow. Snow
showers likely.
.TUESDAY...Northeast winds 15 to 25 knots diminishing to 5 to
15 knots in the afternoon. Areas of blowing snow. Snow showers
likely in the morning. A chance of snow showers in the afternoon.
.TUESDAY NIGHT...North winds 5 to 15 knots backing northwest
after midnight. A chance of snow showers.
.WEDNESDAY...West winds 5 to 15 knots backing southwest.
.THURSDAY...Southwest winds 5 to 15 knots.

Note, waves omitted for mostly ice covered areas.

$$

LSZ263-182300-
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-
951 AM EST Sun Feb 18 2018

.REST OF TODAY...South winds 5 to 15 knots becoming southeast
10 to 20 knots by late morning, then becoming east 15 to 25 knots
by mid afternoon. A chance of snow showers late in the morning,
then snow showers in the afternoon. Patchy blowing snow in the
afternoon.
.TONIGHT...Northeast winds 15 to 25 knots backing north by
midnight. Patchy blowing snow. Snow showers in the evening. A
chance of snow showers after midnight.
.MONDAY...Northeast winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. Areas of blowing snow. A chance of
snow showers in the morning. Snow showers likely in the
afternoon.
.MONDAY NIGHT...Northeast winds 20 to 30 knots. Areas of blowing
snow. Snow showers likely.
.TUESDAY...Northeast winds 15 to 25 knots diminishing to 5 to
15 knots in the afternoon. Areas of blowing snow. Snow showers
likely in the morning. A chance of snow showers in the afternoon.
.TUESDAY NIGHT...North winds 5 to 15 knots backing northwest
after midnight. A chance of snow showers.
.WEDNESDAY...West winds 5 to 15 knots backing southwest. A chance
of snow showers.
.THURSDAY...Southwest winds 5 to 15 knots.

Note, waves omitted for mostly ice covered areas.

$$

LSZ264-182300-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
951 AM EST Sun Feb 18 2018

.REST OF TODAY...Southeast winds 5 to 15 knots increasing to
15 to 25 knots. A chance of snow showers late in the morning,
then snow showers in the afternoon. Patchy blowing snow in the
afternoon.
.TONIGHT...Northeast winds 15 to 25 knots backing north by
midnight. Patchy blowing snow. Snow showers in the evening. A
chance of snow showers after midnight.
.MONDAY...North winds 15 to 25 knots veering northeast. Areas of
blowing snow. A chance of snow showers.
.MONDAY NIGHT...Northeast winds 15 to 25 knots. Areas of blowing
snow. A chance of snow showers.
.TUESDAY...Northeast winds 10 to 20 knots diminishing to 5 to
15 knots in the afternoon. Areas of blowing snow. Snow showers
likely.
.TUESDAY NIGHT...North winds 5 to 15 knots backing northwest
after midnight. A chance of snow showers.
.WEDNESDAY...West winds 5 to 15 knots backing southwest. A chance
of snow showers.
.THURSDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots.

Note, waves omitted for mostly ice covered areas.

$$

LSZ265-182300-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
951 AM EST Sun Feb 18 2018

.REST OF TODAY...South winds 5 to 15 knots becoming southeast
10 to 20 knots by late morning, then becoming south 15 to
25 knots by mid afternoon. A chance of snow showers late in the
morning, then snow showers likely in the afternoon. Patchy
blowing snow in the afternoon.
.TONIGHT...South winds 10 to 20 knots backing north by midnight,
then increasing to 15 to 25 knots late. Snow showers likely in
the evening, then a chance of snow showers, possibly mixed with
freezing rain after midnight. Patchy blowing snow after midnight.
.MONDAY...North winds 20 to 30 knots veering northeast by mid
afternoon. Areas of blowing snow. A chance of snow showers in the
morning. Snow showers, possibly mixed with freezing rain in the
afternoon.
.MONDAY NIGHT...Northeast winds 20 to 30 knots diminishing to
15 to 25 knots after midnight. Patchy blowing snow. Snow showers
likely in the evening. A slight chance of freezing rain. A chance
of snow showers after midnight.
.TUESDAY...Northeast winds 10 to 20 knots. Patchy blowing snow in
the morning. Snow showers likely.
.TUESDAY NIGHT...North winds 10 to 20 knots becoming northwest
15 to 25 knots after midnight. A chance of snow showers.
.WEDNESDAY...Northwest winds 10 to 20 knots becoming southwest
5 to 15 knots. A chance of snow showers.
.THURSDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots.

Note, waves omitted for mostly ice covered areas.

$$

LSZ266-182300-
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-
951 AM EST Sun Feb 18 2018

.REST OF TODAY...Southwest winds 5 to 15 knots becoming south
10 to 20 knots by late morning, then increasing to 20 to 30 knots
by mid afternoon. A slight chance of snow showers late in the
morning, then snow showers likely in the afternoon. Patchy
blowing snow in the afternoon. Waves 1 to 3 feet subsiding to
calm to 2 feet, then building to 3 to 6 feet occasionally to
8 feet.
.TONIGHT...South winds 20 to 30 knots becoming southwest 15 to
25 knots by midnight, then veering north late. Patchy blowing
snow. Snow showers likely in the evening. A chance of snow
showers, possibly mixed with freezing rain after midnight. Waves
building to 4 to 7 feet occasionally to 9 feet, then subsiding to
1 to 3 feet.
.MONDAY...North winds 15 to 25 knots veering northeast by late
morning, then increasing to 20 to 30 knots by mid afternoon.
Areas of blowing snow. Heavy freezing spray in the afternoon. A
chance of snow showers in the morning. Snow showers, possibly
mixed with freezing rain in the afternoon. Waves building to 3 to
6 feet occasionally to 8 feet.
.MONDAY NIGHT...Northeast winds 20 to 30 knots becoming east
15 to 25 knots after midnight. Heavy freezing spray and areas of
blowing snow. Snow showers likely in the evening. A slight chance
of freezing rain. A chance of snow showers after midnight. Waves
building to 5 to 9 feet occasionally to 11 feet.
.TUESDAY...East winds 10 to 20 knots backing northeast in the
afternoon. Heavy freezing spray and patchy blowing snow in the
morning. Snow showers likely. Freezing rain likely in the
afternoon. Waves subsiding to 1 to 3 feet.
.TUESDAY NIGHT...North winds 10 to 20 knots becoming northwest
15 to 25 knots after midnight. A chance of freezing rain in the
evening. A chance of snow showers. Waves building to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots becoming west 5 to
15 knots. A chance of snow showers. Waves subsiding to calm to
2 feet.
.THURSDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots. Waves calm to 2 feet.

Note, wave height forecasts are for ice free areas.

$$

LSZ267-182300-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
951 AM EST Sun Feb 18 2018

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

Note, wave height forecasts are for ice free areas.

$$
LSZ261-182300-
MAFOR 1816/
Superior West 11227 11237 12137 12830 12130. Chance of snow
showers tonight and Monday morning. Waves omitted for mostly ice
covered areas.

Superior North Central 11317 12337 11137 11837 12830 11130.
Chance of snow showers late this morning and overnight. Waves
omitted for mostly ice covered areas.

Superior South Central 11320 11347 11447 11437 11627 11720 12830.
Chance of snow showers late this morning...overnight...and Monday
morning. Waves omitted for mostly ice covered areas.

Superior East 11510 11440 12447 11547 11620 11820 11130. Chance
of snow showers early this afternoon and late tonight through
Monday morning. Waves 1 to 3 feet building to 3 to 5 feet this
afternoon. Waves 5 to 8 feet subsiding to 3 to 5 feet tonight
through Monday morning.

$$

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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