Great Lakes Forecast
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FZUS63 KMQT 151345
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
945 AM EDT Tue Aug 15 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...High pressure of 30.0 inches over northern Ontario
will build over the Upper Great Lakes today. As the high shifts to
the Lower Great Lakes by late Wednesday afternoon, low pressure
of 29.6 inches will organize over the Central Plains. This low
will track across the Upper Great Lakes on Thursday and reach
southwest Quebec Friday night. In its wake, high pressure of 30.0
inches will shift east to the western Great Lakes late Friday and
then expand over the Great Lakes region on Saturday.

LSZ162-152100-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
945 AM EDT Tue Aug 15 2017 /845 AM CDT Tue Aug 15 2017/

.REST OF TODAY...Northeast winds 5 to 15 knots veering east in
the afternoon. Waves calm to 2 feet building to 1 to 3 feet.
.TONIGHT...East winds 5 to 15 knots. A slight chance of showers
late. Waves calm to 2 feet.
.WEDNESDAY...East winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon. A chance of showers through early
afternoon, then showers by mid afternoon. Waves building to 2 to
4 feet.
.WEDNESDAY NIGHT...East winds 10 to 20 knots. Showers. Waves
building to 3 to 5 feet occasionally to 7 feet.
.THURSDAY...Northeast winds 10 to 20 knots backing north by mid
afternoon. Showers likely through early afternoon, then a chance
of showers by mid afternoon. Waves subsiding to 2 to 4 feet, then
building to 3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...North winds 10 to 20 knots becoming northwest
5 to 15 knots after midnight. Waves subsiding to 1 to 3 feet.
.FRIDAY...West winds 5 to 15 knots. Waves subsiding to calm to
2 feet.
.SATURDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ263-152100-
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-
945 AM EDT Tue Aug 15 2017

.REST OF TODAY...Northeast winds 5 to 15 knots veering east late.
Waves calm to 2 feet.
.TONIGHT...East winds 5 to 15 knots. Waves calm to 2 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots backing east in the
afternoon. A chance of showers. Waves building to 1 to 3 feet.
.WEDNESDAY NIGHT...East winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Showers. Waves building to 3 to 5 feet
occasionally to 7 feet.
.THURSDAY...Northeast winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. Showers. Waves building to 5 to 8 feet
occasionally to 10 feet.
.THURSDAY NIGHT...North winds 15 to 25 knots diminishing to 5 to
15 knots after midnight. A chance of showers. Waves subsiding to
2 to 4 feet.
.FRIDAY...West winds 5 to 15 knots. Waves subsiding to calm to
2 feet.
.SATURDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ264-152100-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
945 AM EDT Tue Aug 15 2017

.REST OF TODAY...Northeast winds 5 to 15 knots. Waves calm to
2 feet.
.TONIGHT...Southwest winds less than 10 knots backing southeast
after midnight, then increasing to 5 to 15 knots late. Waves calm
to 2 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots backing east late. A
chance of showers by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots. A chance of showers
through midnight, then showers likely after midnight. Waves
building to 3 to 5 feet occasionally to 7 feet.
.THURSDAY...East winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. Showers. Waves building to 6 to 9 feet
occasionally to 11 feet.
.THURSDAY NIGHT...Northeast winds 15 to 25 knots becoming north
5 to 15 knots after midnight. A chance of showers. Waves
subsiding to 2 to 4 feet.
.FRIDAY...Northwest winds 5 to 15 knots backing west. Waves
subsiding to calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ265-152100-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
945 AM EDT Tue Aug 15 2017

.REST OF TODAY...North winds 10 to 20 knots becoming northeast
5 to 15 knots late. Waves calm to 2 feet.
.TONIGHT...East winds less than 10 knots becoming southeast 5 to
15 knots after midnight. Waves calm to 2 feet.
.WEDNESDAY...Southeast winds 10 to 20 knots backing east late. A
slight chance of showers by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Southeast winds 10 to 20 knots. A chance of
showers through midnight, then showers likely after midnight.
Waves building to 3 to 5 feet occasionally to 7 feet.
.THURSDAY...Southeast winds 15 to 25 knots becoming east 10 to
20 knots by mid afternoon. Showers and a chance of thunderstorms.
Waves building to 4 to 8 feet occasionally to 10 feet.
.THURSDAY NIGHT...North winds 5 to 15 knots increasing to 15 to
25 knots after midnight. A chance of showers. Waves subsiding to
2 to 4 feet.
.FRIDAY...Northwest winds 10 to 20 knots backing west. A chance
of showers. Waves subsiding to calm to 2 feet.
.SATURDAY...West winds 5 to 15 knots backing southwest. Waves
calm to 2 feet.

$$

LSZ266-152100-
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-
945 AM EDT Tue Aug 15 2017

.REST OF TODAY...North winds 10 to 20 knots diminishing to 5 to
15 knots in the afternoon. Waves calm to 2 feet.
.TONIGHT...North winds less than 10 knots veering southeast late.
Waves calm to 2 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots backing east in the
afternoon, then increasing to 10 to 20 knots late. A slight
chance of showers by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 10 to 20 knots veering southeast
after midnight. A chance of showers. Waves building to 3 to
5 feet occasionally to 7 feet.
.THURSDAY...Southeast winds 15 to 25 knots. Showers. Waves
building to 6 to 9 feet occasionally to 11 feet.
.THURSDAY NIGHT...East winds 10 to 20 knots backing north after
midnight. Showers likely through midnight, then a chance of
showers after midnight. Waves subsiding to 2 to 4 feet.
.FRIDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to calm to 2 feet.
.SATURDAY...West winds 5 to 15 knots backing southwest. Waves
calm to 2 feet.

$$

LSZ267-152100-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
945 AM EDT Tue Aug 15 2017

.REST OF TODAY...North winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon, then backing northwest late. Waves
calm to 2 feet.
.TONIGHT...North winds 5 to 15 knots diminishing to less than
10 knots after midnight, then veering southeast late. Waves calm
to 2 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots backing east in the
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 10 to 20 knots veering southeast
after midnight. A chance of showers after midnight. Waves
building to 2 to 4 feet.
.THURSDAY...Southeast winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. Showers likely. Waves building to 4 to
7 feet occasionally to 9 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.THURSDAY NIGHT...Southeast winds 15 to 25 knots becoming
northeast 10 to 20 knots after midnight. Showers likely. Waves
subsiding to 1 to 3 feet.
.FRIDAY...Northwest winds 10 to 20 knots. A chance of showers.
Waves building to 3 to 5 feet occasionally to 7 feet, then
subsiding to calm to 2 feet.
.SATURDAY...West winds 10 to 20 knots becoming southwest 5 to
15 knots. Waves calm to 2 feet.

$$
LSZ261-152100-
MAFOR 1515/
Superior West 15200 12210. Chance of showers Wednesday morning.
Waves 1 to 2 feet.

Superior North Central 11100 11800 11700 11500 11400 12300 11310.
Waves 2 feet or less.

Superior South Central 11810 12800 11100 13300 11310. Waves 1
foot or less.

Superior East 12800 12700 11800 11700 11400 11300. Waves 1 foot
or less.

$$

MZ

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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