Great Lakes Forecast
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000
FZUS63 KMQT 251409
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1009 AM EDT Mon Sep 25 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...Low pressure of 29.8 inches over northern Ontario
will reach western Quebec by this afternoon dragging a 29.9 inch
trough across Lake Superior. Low pressure of 29.9 inches will
develop over western Wisconsin on the tail end of the trough and
move over Lake Superior through Tuesday night. High pressure of
30.1 inches will build into the Upper Great Lakes for Wednesday
into early Thursday. A low pressure trough of 30.0 inches will
drop out of Canada across Lake Superior late Thursday afternoon.
High pressure ridging of 30.4 inches will quickly build into the
Upper Lakes behind the trough for Thursday night and Friday.


LSZ162-252215-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1009 AM EDT Mon Sep 25 2017 /909 AM CDT Mon Sep 25 2017/

.REST OF TODAY...Northwest winds 5 to 15 knots. Scattered showers
by late morning, then numerous showers and isolated thunderstorms
by mid afternoon. Waves calm to 2 feet.
.TONIGHT...Northeast winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Patchy fog. Numerous showers. Isolated
thunderstorms after midnight. Waves building to 3 to 6 feet
occasionally to 8 feet.
.TUESDAY...Northeast winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon, then backing north late. Showers
likely through early afternoon, then a chance of showers by mid
afternoon. Waves subsiding to 2 to 4 feet.
.TUESDAY NIGHT...Northwest winds 10 to 20 knots increasing to
15 to 25 knots after midnight. A chance of showers. Waves
subsiding to 1 to 3 feet, then building to 2 to 4 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots. Waves calm to
2 feet.
.THURSDAY...West winds 10 to 20 knots becoming north 15 to
25 knots. A chance of showers. Waves building to 3 to 5 feet
occasionally to 7 feet.
.FRIDAY...North winds 15 to 25 knots diminishing to 5 to
15 knots. Waves subsiding to calm to 2 feet.

$$

LSZ263-252215-
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-
1009 AM EDT Mon Sep 25 2017

.REST OF TODAY...West winds 5 to 15 knots veering north late.
Scattered showers and isolated thunderstorms. Waves calm to
2 feet.
.TONIGHT...Northeast winds 10 to 20 knots. Patchy fog. Numerous
showers and isolated thunderstorms. Waves building to 3 to 6 feet
occasionally to 8 feet.
.TUESDAY...Northeast winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon. Showers likely through early
afternoon, then a chance of showers by mid afternoon. Waves
subsiding to 3 to 5 feet occasionally to 7 feet.
.TUESDAY NIGHT...Northwest winds 5 to 15 knots increasing to
10 to 20 knots after midnight. A chance of showers. Waves
subsiding to 2 to 4 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots becoming west 5 to
15 knots by mid afternoon. Waves subsiding to 1 to 3 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to
calm to 2 feet, then building to 1 to 3 feet.
.THURSDAY...West winds 10 to 20 knots becoming north 15 to
25 knots. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet.
.FRIDAY...North winds 15 to 25 knots diminishing to 5 to
15 knots. Waves subsiding to calm to 2 feet.

$$

LSZ264-252215-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1009 AM EDT Mon Sep 25 2017

.REST OF TODAY...West winds 5 to 15 knots veering north late.
Isolated thunderstorms by late morning. Isolated showers. Waves
1 to 3 feet subsiding to calm to 2 feet.
.TONIGHT...North winds 10 to 20 knots veering northeast after
midnight. Scattered thunderstorms through midnight. Scattered
showers. Waves building to 3 to 5 feet occasionally to 7 feet.
.TUESDAY...Northeast winds 10 to 20 knots. Showers through early
afternoon, then a chance of showers by mid afternoon. Waves
building to 3 to 6 feet occasionally to 8 feet.
.TUESDAY NIGHT...Northwest winds 10 to 20 knots increasing to
15 to 25 knots after midnight. A chance of showers. Waves
subsiding to 1 to 3 feet, then building to 2 to 4 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 1 to 3 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.THURSDAY...West winds 5 to 15 knots becoming north 20 to
30 knots. A chance of showers. Waves building to 2 to 4 feet,
then subsiding to 1 to 3 feet.
.FRIDAY...North winds 20 to 30 knots diminishing to 10 to
20 knots. Waves subsiding to calm to 2 feet.

$$

LSZ265-252215-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1009 AM EDT Mon Sep 25 2017

.REST OF TODAY...Southwest winds 5 to 15 knots veering northwest
in the afternoon, then becoming north 10 to 20 knots late.
Scattered showers and thunderstorms by mid afternoon. Waves calm
to 2 feet.
.TONIGHT...North winds 10 to 20 knots becoming northeast 5 to
15 knots late. Scattered showers and thunderstorms. Patchy fog
after midnight. Waves building to 2 to 4 feet.
.TUESDAY...East winds 5 to 15 knots increasing to 10 to 20 knots
in the afternoon, then backing northeast late. A chance of
showers through early afternoon. A slight chance of
thunderstorms. Showers likely by mid afternoon. Waves subsiding
to calm to 2 feet.
.TUESDAY NIGHT...Northwest winds 10 to 20 knots increasing to
20 to 30 knots after midnight. A chance of showers. Waves
building to 2 to 4 feet.
.WEDNESDAY...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots by mid afternoon. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 1 to 3 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots. Waves subsiding to
calm to 2 feet.
.THURSDAY...West winds 10 to 20 knots becoming northwest 20 to
30 knots. A chance of showers. Waves building to 6 to 9 feet
occasionally to 11 feet.
.FRIDAY...North winds 20 to 30 knots diminishing to 10 to
20 knots. Waves building to 7 to 10 feet occasionally to 13 feet,
then subsiding to 1 to 3 feet.

$$

LSZ266-252215-
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-
1009 AM EDT Mon Sep 25 2017

.REST OF TODAY...Southwest winds 5 to 15 knots veering west in
the afternoon, then becoming north 10 to 20 knots late. Isolated
showers. Isolated thunderstorms by mid afternoon. Waves 1 to
3 feet subsiding to calm to 2 feet.
.TONIGHT...North winds 5 to 15 knots increasing to 10 to 20 knots
after midnight, then veering northeast late. Patchy fog.
Scattered showers and thunderstorms. Waves building to 3 to
5 feet occasionally to 7 feet.
.TUESDAY...East winds 5 to 15 knots veering southeast in the
afternoon. A chance of showers through early afternoon. A slight
chance of thunderstorms. Showers likely by mid afternoon. Waves
subsiding to 1 to 3 feet.
.TUESDAY NIGHT...West winds 15 to 25 knots becoming northwest
20 to 30 knots after midnight. A chance of showers. Waves
building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots by mid afternoon. Waves building to 3 to 6 feet
occasionally to 8 feet.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 knots becoming west
10 to 20 knots after midnight. Waves subsiding to 1 to 3 feet.
.THURSDAY...Southwest winds 10 to 20 knots becoming northwest
gales to 35 knots. A chance of showers. Waves building to 2 to
4 feet, then subsiding to 1 to 3 feet.
.FRIDAY...North gales to 35 knots diminishing to 15 to 25 knots.
A chance of showers. Waves building to 8 to 11 feet occasionally
to 14 feet, then subsiding to 1 to 3 feet.

$$

LSZ267-252215-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1009 AM EDT Mon Sep 25 2017

.REST OF TODAY...Southwest winds 10 to 20 knots becoming west
5 to 15 knots in the afternoon, then veering north late. Isolated
showers by late morning. Waves 1 to 3 feet subsiding to calm to
2 feet.
.TONIGHT...North winds 5 to 15 knots veering northeast late.
Patchy fog. Isolated showers and thunderstorms. Waves calm to
2 feet.
.TUESDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots late. A chance of showers through early afternoon. A
chance of thunderstorms. Showers likely by mid afternoon. Waves
calm to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots increasing to 20 to
30 knots after midnight. Showers likely and a slight chance of
thunderstorms through midnight, then a chance of showers after
midnight. Waves building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...Northwest winds 20 to 30 knots. Waves building to
3 to 6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. Waves subsiding to 1 to 3 feet.
.THURSDAY...Southwest winds 10 to 20 knots becoming northwest
20 to 30 knots. A chance of showers. Waves subsiding to calm to
2 feet, then building to 4 to 7 feet occasionally to 9 feet.
.FRIDAY...North winds 20 to 30 knots diminishing to 15 to
25 knots. A chance of showers. Waves building to 6 to 9 feet
occasionally to 11 feet, then subsiding to 1 to 3 feet.

$$
LSZ261-252215-
MAFOR 2515/
Superior West 12700 11806 11126 14136. Scattered showers this
afternoon. Patchy fog overnight and Tuesday morning. Waves 2 feet
or less this afternoon building to 3 to 5 feet tonight. Waves 4
to 6 feet Tuesday morning.

Superior North Central 11610 11710 11810 11820 12120 11126 11136.
Scattered showers through tonight. Scattered thunderstorms late
in the evening. Patchy fog Tuesday morning. Waves 1 to 5 feet.

Superior South Central 11600 14810 11810 11110 11200. Patchy fog
overnight and Tuesday morning. Scattered showers and
thunderstorms through the early overnight...Then scattered showers
late tonight. Chance of showers Tuesday morning. Waves 3 feet or
less.

Superior East 11510 11600 12800 11700 11810 11120 11210. Patchy
fog through early evening tonight. Chance of showers tonight through
mid morning...Then chance of showers and thunderstorms late
Tuesday morning. Waves 3 feet or less.

$$

WFO MQT

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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