Great Lakes Forecast
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FZUS63 KMQT 190753
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
353 AM EDT Tue Sep 19 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 30.2 inches centered just east of
Lake Superior will move to southern Quebec today. Meanwhile, a
29.4 inch trough emerging over the Plains states today will weaken
to 29.8 inches as it sweeps eastward, passing across Lake Superior
Wednesday afternoon and evening. In its wake, 30.1 inch high
pressure will shift across Lake Superior on Thursday. On Friday
and Saturday, Lake Superior will be situated between 30.1 inch
high pressure centered near the Lower Great Lakes and a 29.8 inch
trough extending from Nebraska to northern Ontario.

LSZ162-191600-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
353 AM EDT Tue Sep 19 2017 /253 AM CDT Tue Sep 19 2017/

.EARLY THIS MORNING...Southeast winds 5 to 15 knots. Waves calm
to 2 feet.
.TODAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots in the afternoon, then increasing to 15 to 25 knots
late. Waves building to 1 to 3 feet.
.TONIGHT...East winds 15 to 25 knots veering southeast after
midnight. A chance of showers and thunderstorms late. Waves
building to 2 to 4 feet.
.WEDNESDAY...Southeast winds 15 to 25 knots veering southwest in
the afternoon, then becoming west 10 to 20 knots late. Showers
likely through early afternoon, then a chance of showers. A
chance of thunderstorms. Waves subsiding to 1 to 3 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.THURSDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...East winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. A chance of showers. Waves calm to
2 feet.
.FRIDAY...East winds 5 to 15 knots increasing to 10 to 20 knots.
A chance of showers and thunderstorms. Waves building to 1 to
3 feet, then subsiding to calm to 2 feet.
.SATURDAY...Southwest winds 10 to 20 knots becoming west 5 to
15 knots. A chance of showers. Showers likely. Waves calm to
2 feet.

$$

LSZ263-191600-
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-
353 AM EDT Tue Sep 19 2017

.EARLY THIS MORNING...Southeast winds 5 to 15 knots. Waves calm
to 2 feet.
.TODAY...Southeast winds 5 to 15 knots backing east in the
afternoon, then increasing to 10 to 20 knots late. Waves building
to 1 to 3 feet.
.TONIGHT...East winds 10 to 20 knots veering southeast after
midnight. A slight chance of showers and thunderstorms late.
Waves building to 2 to 4 feet.
.WEDNESDAY...Southeast winds 15 to 25 knots veering south in the
afternoon, then becoming southwest 10 to 20 knots late. Showers
likely through early afternoon, then a chance of showers. A
chance of thunderstorms. Waves building to 3 to 6 feet occasionally
to 8 feet, then subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots diminishing to less
than 10 knots after midnight. A slight chance of showers through
midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...South winds less than 10 knots becoming east 5 to
15 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 5 to 15 knots. A chance of
showers. Waves calm to 2 feet.
.FRIDAY...Southeast winds 5 to 15 knots. A chance of showers and
thunderstorms. Waves calm to 2 feet.
.SATURDAY...South winds 5 to 15 knots veering southwest. A chance
of showers. Waves calm to 2 feet.

$$

LSZ264-191600-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
353 AM EDT Tue Sep 19 2017

.EARLY THIS MORNING...Southeast winds 5 to 15 knots. Waves calm
to 2 feet.
.TODAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots late. Waves building to 1 to 3 feet.
.TONIGHT...Southeast winds 10 to 20 knots increasing to 15 to
25 knots late. Waves building to 3 to 5 feet occasionally to
7 feet.
.WEDNESDAY...Southeast winds 20 to 30 knots veering south late. A
chance of showers through early afternoon, then showers likely. A
chance of thunderstorms. Waves building to 5 to 8 feet
occasionally to 10 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots becoming northwest
5 to 15 knots after midnight. A slight chance of showers and
thunderstorms through midnight. Waves subsiding to calm to
2 feet.
.THURSDAY...South winds less than 10 knots becoming southeast
5 to 15 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 5 to 15 knots. A chance of
showers. Waves building to 1 to 3 feet.
.FRIDAY...South winds 5 to 15 knots backing southeast. A chance
of showers and thunderstorms. Waves subsiding to calm to 2 feet.
.SATURDAY...South winds 5 to 15 knots veering southwest. A chance
of showers. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.

$$

LSZ265-191600-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
353 AM EDT Tue Sep 19 2017

.EARLY THIS MORNING...Southeast winds 10 to 20 knots. Waves calm
to 2 feet.
.TODAY...Southeast winds 10 to 20 knots backing east in the
afternoon, then increasing to 15 to 25 knots late. Waves building
to 1 to 3 feet.
.TONIGHT...Southeast winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Waves building to 2 to 4 feet.
.WEDNESDAY...Southeast winds 15 to 25 knots increasing to 20 to
30 knots in the afternoon, then becoming south 15 to 25 knots
late. A chance of showers and thunderstorms. Waves building to
3 to 6 feet occasionally to 8 feet, then subsiding to 2 to
4 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots becoming northwest
5 to 15 knots after midnight. A chance of showers and
thunderstorms through midnight. Waves subsiding to calm to
2 feet.
.THURSDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 10 to 20 knots veering south
after midnight. A chance of showers after midnight. Waves calm to
2 feet.
.FRIDAY...South winds 10 to 20 knots. A chance of showers. Waves
calm to 2 feet.
.SATURDAY...South winds 10 to 20 knots veering southwest. A
chance of showers. Waves calm to 2 feet.

$$

LSZ266-191600-
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-
353 AM EDT Tue Sep 19 2017

.EARLY THIS MORNING...Southeast winds 10 to 20 knots. Isolated
showers. Waves calm to 2 feet.
.TODAY...Southeast winds 5 to 15 knots backing east in the
afternoon, then increasing to 10 to 20 knots late. Waves building
to 1 to 3 feet.
.TONIGHT...East winds 10 to 20 knots becoming southeast 15 to
25 knots after midnight. Waves building to 2 to 4 feet.
.WEDNESDAY...Southeast winds 20 to 30 knots veering south late. A
chance of showers. A chance of thunderstorms by mid afternoon.
Waves building to 4 to 7 feet occasionally to 9 feet, then
subsiding to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...Southwest winds 10 to 20 knots becoming
northwest 5 to 15 knots after midnight. A chance of showers and
thunderstorms through midnight. Waves subsiding to calm to 2
feet.
.THURSDAY...North winds 5 to 15 knots veering east by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 10 to 20 knots veering south
after midnight. A chance of showers. Waves building to 1 to
3 feet.
.FRIDAY...South winds 10 to 20 knots. A chance of showers. Waves
subsiding to calm to 2 feet.
.SATURDAY...South winds 10 to 20 knots veering southwest. A
chance of showers. Waves building to 1 to 3 feet, then subsiding
to calm to 2 feet.

$$

LSZ267-191600-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
353 AM EDT Tue Sep 19 2017

.EARLY THIS MORNING...East winds 10 to 20 knots. Isolated
showers. Waves calm to 2 feet.
.TODAY...Southeast winds 10 to 20 knots becoming east 5 to
15 knots in the afternoon. Waves calm to 2 feet.
.TONIGHT...East winds 5 to 15 knots becoming southeast 10 to
20 knots after midnight, then increasing to 15 to 25 knots late.
Waves building to 1 to 3 feet.
.WEDNESDAY...Southeast winds 15 to 25 knots increasing to 20 to
30 knots in the afternoon, then becoming south 15 to 25 knots
late. A slight chance of showers and thunderstorms by mid
afternoon. Waves building to 2 to 4 feet.
.WEDNESDAY NIGHT...South winds 10 to 20 knots becoming northwest
5 to 15 knots after midnight. A chance of showers and
thunderstorms. Waves subsiding to calm to 2 feet.
.THURSDAY...North winds 5 to 15 knots. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 5 to 15 knots becoming south
10 to 20 knots after midnight. A chance of showers. Waves
building to 1 to 3 feet.
.FRIDAY...South winds 10 to 20 knots. A chance of showers. Waves
subsiding to calm to 2 feet.
.SATURDAY...South winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ261-191600-
MAFOR 1909/
Superior West 13300 11220 12230 12330. Waves 1 to 3 feet.

Superior North Central 13310 11320 11220 13320. Waves 1 to 4
feet.

Superior South Central 13310 12220 13320. Waves 1 to 3 feet.

Superior East 12310 11200 13210 12320. Waves 1 to 3 feet.

$$

Rolfson

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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