Great Lakes Forecast
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503
FZUS63 KMQT 202051
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
351 PM 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 north of Sudbury will push
northeastward overnight, reaching Quebec early Wednesday morning.
A high pressure system of 30.6 inches over the Northern Plains
will then push towards the Great Lakes Wednesday afternoon and
drift into southern Quebec on 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. A 29.1 inch low pressure
system will then track from the Mid Mississippi Valley into the
Upper Great Lakes on Sunday.

LSZ162-210500-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
351 PM EST Tue Feb 20 2018 /251 PM CST Tue Feb 20 2018/

.LATE THIS AFTERNOON...West winds 10 to 20 knots. Patchy fog. A
slight chance of snow showers.
.TONIGHT...West winds 15 to 25 knots diminishing to 10 to
20 knots by midnight. A slight chance of snow showers.
.WEDNESDAY...West winds 10 to 20 knots increasing to 15 to
25 knots by late morning, then backing southwest by mid
afternoon.
.WEDNESDAY NIGHT...Southwest winds 10 to 20 knots diminishing to
5 to 15 knots by midnight.
.THURSDAY...South winds less than 10 knots becoming southeast
5 to 15 knots in the afternoon.
.THURSDAY NIGHT...Southeast winds less than 10 knots. A chance of
snow in the evening, then snow likely after midnight.
.FRIDAY...Southeast winds 5 to 15 knots veering west in the
afternoon. A chance of snow.
.FRIDAY NIGHT...West winds 5 to 15 knots veering northwest after
midnight.
.SATURDAY...Southeast winds 5 to 15 knots backing east. A chance
of snow.
.SUNDAY...West winds 10 to 20 knots.

Note, waves omitted for mostly ice covered areas.

$$

LSZ263-210500-
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-
351 PM EST Tue Feb 20 2018

.LATE THIS AFTERNOON...Northwest winds 5 to 15 knots. Patchy fog.
A chance of snow showers.
.TONIGHT...West winds 10 to 20 knots veering northwest by
midnight, then backing west late. A chance of snow showers.
.WEDNESDAY...West winds 10 to 20 knots increasing to 15 to
25 knots. 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 by midnight.
.THURSDAY...South winds less than 10 knots increasing to 5 to
15 knots in the afternoon.
.THURSDAY NIGHT...South winds 5 to 15 knots. A chance of snow in
the evening, then snow likely after midnight.
.FRIDAY...Southeast winds 5 to 15 knots veering west in the
afternoon. Snow likely in the morning, then a chance of snow in
the afternoon.
.FRIDAY NIGHT...West winds 5 to 15 knots veering northwest after
midnight.
.SATURDAY...Southeast winds 5 to 15 knots backing east. A chance
of snow.
.SUNDAY...West winds 10 to 20 knots.

Note, waves omitted for mostly ice covered areas.

$$

LSZ264-210500-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
351 PM EST Tue Feb 20 2018

.LATE THIS AFTERNOON...North winds 5 to 15 knots. Patchy fog. A
chance of snow showers and a slight chance of freezing drizzle.
.TONIGHT...Northwest winds 5 to 15 knots increasing to 10 to
20 knots by midnight. Patchy fog in the evening. A slight chance
of snow showers.
.WEDNESDAY...West winds 5 to 15 knots increasing to 15 to
25 knots by late morning, then backing southwest by mid
afternoon. Patchy blowing snow in the afternoon.
.WEDNESDAY NIGHT...Southwest winds 10 to 20 knots diminishing to
5 to 15 knots late.
.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.
.FRIDAY...South winds 5 to 15 knots veering west in the
afternoon. Snow likely in the morning, then a chance of snow in
the afternoon.
.FRIDAY NIGHT...West winds 5 to 15 knots veering northwest after
midnight.
.SATURDAY...Southeast winds 5 to 15 knots backing east. A chance
of snow.
.SUNDAY...West winds 10 to 20 knots. A chance of snow.

Note, waves omitted for mostly ice covered areas.

$$

LSZ265-210500-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
351 PM EST Tue Feb 20 2018

.LATE THIS AFTERNOON...Northwest winds 10 to 20 knots. Patchy
fog. A slight chance of freezing drizzle.
.TONIGHT...Northwest winds 10 to 20 knots. Patchy fog in the
evening.
.WEDNESDAY...West winds 10 to 20 knots.
.WEDNESDAY NIGHT...Southwest winds 10 to 20 knots diminishing to
5 to 15 knots by midnight.
.THURSDAY...South winds 5 to 15 knots backing southeast in the
afternoon.
.THURSDAY NIGHT...Southeast winds 10 to 20 knots. Snow likely
after midnight.
.FRIDAY...Southeast winds 10 to 20 knots veering west in the
afternoon. Snow likely in the morning.
.FRIDAY NIGHT...West winds 10 to 20 knots becoming northwest 5 to
15 knots after midnight.
.SATURDAY...East winds 5 to 15 knots increasing to 10 to
20 knots. Snow likely.
.SUNDAY...West winds 10 to 20 knots increasing to 15 to 25 knots.
A chance of snow.

Note, waves omitted for mostly ice covered areas.

$$

LSZ266-210500-
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-
351 PM EST Tue Feb 20 2018

.LATE THIS AFTERNOON...West winds 10 to 20 knots. Patchy fog. A
slight chance of freezing drizzle. Waves 1 to 3 feet.
.TONIGHT...Northwest winds 15 to 25 knots increasing to 20 to
30 knots by midnight, then diminishing to 15 to 25 knots late.
Patchy fog in the evening. A slight chance of freezing drizzle in
the evening. 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 by 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 backing southeast
after midnight. Snow likely after midnight. Waves calm to 2 feet.
.FRIDAY...Southeast winds 10 to 20 knots veering southwest in the
afternoon. Snow likely in the morning, then a chance of freezing
drizzle in the afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...West winds 10 to 20 knots veering northwest after
midnight. Waves calm to 2 feet.
.SATURDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots. Snow likely. Waves building to 1 to 3 feet.
.SUNDAY...West winds 15 to 25 knots. A chance of snow. Waves
building to 2 to 4 feet.

Note, wave height forecasts are for ice free areas.

$$

LSZ267-210500-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
351 PM EST Tue Feb 20 2018

.LATE THIS AFTERNOON...West winds 5 to 15 knots. Patchy fog. A
chance of freezing drizzle. Waves calm to 2 feet.
.TONIGHT...West winds 15 to 25 knots becoming northwest 20 to
30 knots by midnight. Patchy fog in the evening. Freezing spray
and patchy blowing snow after midnight. A slight chance of
freezing drizzle in the evening. A slight chance of snow showers.
Waves building to 4 to 7 feet occasionally to 9 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots. Freezing spray in the morning. A slight chance of snow
showers. Waves subsiding to 1 to 3 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots backing southwest by
midnight, then diminishing to 5 to 15 knots late. Waves subsiding
to calm to 2 feet.
.THURSDAY...South winds 5 to 15 knots backing southeast in the
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 10 to 20 knots. A chance of
snow. Waves calm to 2 feet.
.FRIDAY...Southeast winds 10 to 20 knots veering southwest in the
afternoon. Snow likely in the morning, then a chance of freezing
drizzle in the afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...West winds 10 to 20 knots veering northwest after
midnight. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots increasing to 10 to
20 knots. Snow likely. Waves building to 1 to 3 feet.
.SUNDAY...West winds 15 to 25 knots. Snow likely, then a chance
of snow. 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.

$$

LSZ261-210500-
MAFOR 2022/
Superior West 12630 12730 12620 11630 11530. Patchy fog and snow
showers late this evening. Waves omitted for mostly ice covered
areas.

Superior North Central 11820 14720 11610 11620 11630. Patchy fog and snow
showers late this evening. Waves omitted for mostly ice covered
areas.

Superior South Central 11730 13720 11710 13620. Patchy fog this
evening. Waves omitted for mostly ice covered areas.

Superior East 11630 11730 11740 12742 11732 11730 11620. Patchy
fog and freezing spray this evening. Chance of light freezing
drizzle tonight. Waves 1 to 3 feet building to 4 to 7 feet
tonight, then subsiding to 2 to 4 feet Wednesday.

$$

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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