Great Lakes Forecast
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902
FZUS63 KMQT 241941
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
341 PM EDT Sun Sep 24 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 far western Ontario
will move northeastward into northwestern Quebec by Monday afternoon
dragging a low pressure trough of 29.9 inches across Lake Superior.
Low pressure of 29.9 inches will develop over western Wisconsin
on the tail end of the trough and lift northeastward across Lake
Superior on Tuesday and Tuesday night. High pressure of 30.1
inches will build into the Upper Great Lakes for Wednesday into
early Thursday. A quick moving low pressure trough of 30.0 inches
will drop southeastward 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.

LSZ162-250345-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
341 PM EDT Sun Sep 24 2017 /241 PM CDT Sun Sep 24 2017/

.LATE THIS AFTERNOON...East winds 5 to 15 knots. Widespread fog.
Waves calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest after
midnight. Widespread fog through midnight. Patchy fog after
midnight. A chance of showers. Waves calm to 2 feet.
.MONDAY...West winds 5 to 15 knots veering northwest in the
afternoon, then veering northeast late. Patchy fog. A chance of
showers. A slight chance of thunderstorms by mid afternoon. Waves
calm to 2 feet.
.MONDAY NIGHT...Northeast winds 10 to 20 knots increasing to
15 to 25 knots after midnight. A slight chance of thunderstorms
through midnight. Showers likely. Waves building to 2 to 4 feet.
.TUESDAY...Northeast winds 10 to 20 knots backing northwest by
mid afternoon. Showers likely through early afternoon, then a
chance of showers by mid afternoon. Waves subsiding to 1 to
3 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots becoming northwest
15 to 25 knots after midnight. Waves 1 to 3 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 veering north. A chance of
showers. Waves calm to 2 feet.
.FRIDAY...North winds 10 to 20 knots backing northwest. Waves
building to 1 to 3 feet.

$$

LSZ263-250345-
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-
341 PM EDT Sun Sep 24 2017

.LATE THIS AFTERNOON...South winds 5 to 15 knots. Waves calm to
2 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest late. A
slight chance of showers after midnight. Waves building to 1 to
3 feet.
.MONDAY...West winds 5 to 15 knots veering northwest in the
afternoon, then veering northeast late. Patchy fog through early
afternoon. A chance of showers and a slight chance of
thunderstorms. Waves subsiding to calm to 2 feet.
.MONDAY NIGHT...Northeast winds 10 to 20 knots. A slight chance
of thunderstorms through midnight. Showers likely. Waves building
to 2 to 4 feet.
.TUESDAY...Northeast winds 10 to 20 knots becoming northwest 5 to
15 knots by mid afternoon. Showers likely through early
afternoon, then a chance of showers by mid afternoon. Waves
subsiding to 1 to 3 feet.
.TUESDAY NIGHT...Northwest winds 15 to 25 knots. A chance of
showers. Waves 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 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 10 to
20 knots. A chance of showers. Waves calm to 2 feet.
.FRIDAY...North winds 10 to 20 knots backing northwest. Waves
building to 2 to 4 feet.

$$

LSZ264-250345-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
341 PM EDT Sun Sep 24 2017

.LATE THIS AFTERNOON...South winds 5 to 15 knots. Waves calm to
2 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest late. A
slight chance of showers after midnight. Waves building to 2 to
4 feet, then subsiding to 1 to 3 feet.
.MONDAY...West winds 5 to 15 knots veering north late. A chance
of showers. Waves subsiding to calm to 2 feet.
.MONDAY NIGHT...North winds 5 to 15 knots becoming northeast
10 to 20 knots after midnight. A chance of showers through
midnight. A slight chance of thunderstorms. Showers likely after
midnight. Waves building to 2 to 4 feet.
.TUESDAY...Northeast winds 10 to 20 knots becoming northwest 5 to
15 knots by mid afternoon. Showers likely. Waves subsiding to
1 to 3 feet.
.TUESDAY NIGHT...Northwest winds 15 to 25 knots. A chance of
showers. Waves subsiding to calm to 2 feet, then building to 2 to
4 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots backing west by mid
afternoon. Waves building to 3 to 5 feet occasionally to 7 feet,
then subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...Northwest winds 10 to 20 knots becoming west
5 to 15 knots after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...West winds 5 to 15 knots becoming north 10 to
20 knots. A chance of showers. Waves building to 1 to 3 feet.
.FRIDAY...North winds 15 to 25 knots backing northwest. Waves
building to 3 to 5 feet occasionally to 7 feet.

$$

LSZ265-250345-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
341 PM EDT Sun Sep 24 2017

.LATE THIS AFTERNOON...South winds 5 to 15 knots. Waves calm to
2 feet.
.TONIGHT...South winds 10 to 20 knots veering southwest late.
Waves building to 2 to 4 feet, then subsiding to calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots veering northwest in the
afternoon, then veering north late. A chance of showers and a
slight chance of thunderstorms by mid afternoon. Waves calm to
2 feet.
.MONDAY NIGHT...North winds 5 to 15 knots becoming northeast
10 to 20 knots after midnight. A chance of showers and
thunderstorms. Waves building to 1 to 3 feet.
.TUESDAY...Southeast winds 5 to 15 knots becoming west 10 to
20 knots by mid afternoon. 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...West winds 15 to 25 knots becoming northwest
20 to 30 knots after midnight. A chance of showers. Waves
building to 2 to 4 feet.
.WEDNESDAY...Northwest winds 20 to 30 knots. Waves building to
3 to 5 feet occasionally to 7 feet, then subsiding to 2 to
4 feet.
.WEDNESDAY NIGHT...West winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...West winds 10 to 20 knots becoming north 15 to
25 knots. A chance of showers. Waves building to 1 to 3 feet.
.FRIDAY...North winds 15 to 25 knots backing northwest. Waves
building to 3 to 5 feet occasionally to 7 feet.

$$

LSZ266-250345-
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-
341 PM EDT Sun Sep 24 2017

.LATE THIS AFTERNOON...South winds 10 to 20 knots. Waves calm to
2 feet building to 1 to 3 feet.
.TONIGHT...South winds 15 to 25 knots diminishing to 10 to
20 knots late. Waves building to 2 to 4 feet.
.MONDAY...Southwest winds 5 to 15 knots veering west in the
afternoon, then veering north late. A chance of showers and a
slight chance of thunderstorms by mid afternoon. Waves subsiding
to calm to 2 feet.
.MONDAY NIGHT...North winds 5 to 15 knots becoming northeast
10 to 20 knots after midnight, then veering east late. A chance
of showers and a slight chance of thunderstorms. Waves building
to 2 to 4 feet, then subsiding to 1 to 3 feet.
.TUESDAY...Southeast winds 10 to 20 knots veering south by mid
afternoon. 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...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. Waves building to
5 to 8 feet occasionally to 10 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...West winds 10 to 20 knots becoming northwest 15 to
25 knots. A chance of showers. Waves subsiding to calm to 2 feet,
then building to 1 to 3 feet.
.FRIDAY...North winds 20 to 30 knots becoming northwest 15 to
25 knots. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet.

$$

LSZ267-250345-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
341 PM EDT Sun Sep 24 2017

.LATE THIS AFTERNOON...South winds 10 to 20 knots. Waves calm to
2 feet.
.TONIGHT...South winds 10 to 20 knots. Waves building to 1 to
3 feet.
.MONDAY...South winds 10 to 20 knots becoming west 5 to 15 knots
in the afternoon, then veering north late. A slight chance of
showers and thunderstorms by mid afternoon. Waves subsiding to
calm to 2 feet.
.MONDAY NIGHT...Northeast winds 5 to 15 knots becoming southeast
10 to 20 knots late. A slight chance of showers and
thunderstorms. Waves calm to 2 feet.
.TUESDAY...Southeast winds 10 to 20 knots veering south by mid
afternoon. A chance of showers and thunderstorms. Waves calm to
2 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. Waves building to
5 to 8 feet occasionally to 10 feet.
.WEDNESDAY NIGHT...Northwest winds 20 to 30 knots diminishing to
10 to 20 knots after midnight. Waves subsiding to 1 to 3 feet.
.THURSDAY...West winds 10 to 20 knots increasing to 15 to
25 knots. A chance of showers. Waves subsiding to calm to 2 feet,
then building to 1 to 3 feet.
.FRIDAY...North winds 20 to 30 knots. A chance of showers. Waves
building to 3 to 6 feet occasionally to 8 feet.

$$

LSZ261-250345-
MAFOR 2421/
Superior West 11300 12410 12510 11610 11710 11700. Patchy fog in
the morning. Chance of showers Monday. Waves 1 to 3 feet tonight.
Waves 2 feet or less Monday.

Superior North Central 11400 11410 12420 11510 12610 11700.
Chance of showers late Monday. Waves 1 to 3 feet building to 2 to
4 feet tonight. Waves 1 to 3 feet Monday.

Superior South Central 13420 12410 11510 11600 11800. Waves 1 to
3 feet.

Superior East 11410 14420 11420 11510 11600. Waves 1 to 3 feet
building to 2 to 4 feet tonight. Waves 2 to 4 feet subsiding to 1
to 3 feet Monday.

$$

07

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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