Great Lakes Forecast
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192
FZUS63 KMQT 250754
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
354 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 western Ontario will
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.

LSZ162-251600-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
354 AM EDT Mon Sep 25 2017 /254 AM CDT Mon Sep 25 2017/

.EARLY THIS MORNING...West winds 10 to 20 knots. A chance of
showers and a slight chance of thunderstorms. Waves calm to
2 feet.
.TODAY...West winds 5 to 15 knots veering north late. A chance of
showers. A chance of thunderstorms by mid afternoon. Waves calm
to 2 feet.
.TONIGHT...Northeast winds 10 to 20 knots increasing to 15 to
25 knots late. Showers likely and a slight chance of
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, 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.

$$

LSZ263-251600-
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-
354 AM EDT Mon Sep 25 2017

.EARLY THIS MORNING...Southwest winds 5 to 15 knots. A slight
chance of showers and thunderstorms. Waves 1 to 3 feet.
.TODAY...West winds 5 to 15 knots becoming northwest less than
10 knots in the afternoon, then becoming north 5 to 15 knots
late. A chance of showers and thunderstorms. Waves subsiding to
calm to 2 feet.
.TONIGHT...Northeast winds 10 to 20 knots. A chance of showers
through midnight. A chance of thunderstorms. Showers likely 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. 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.

$$

LSZ264-251600-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
354 AM EDT Mon Sep 25 2017

.EARLY THIS MORNING...Southwest winds 5 to 15 knots. A slight
chance of showers and thunderstorms. Waves 2 to 4 feet subsiding
to 1 to 3 feet.
.TODAY...West winds 5 to 15 knots veering north late. A slight
chance of thunderstorms through early afternoon. A slight chance
of showers. Waves subsiding to calm to 2 feet.
.TONIGHT...North winds 5 to 15 knots veering northeast after
midnight, then increasing to 10 to 20 knots late. A slight chance
of thunderstorms through midnight. A chance of 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.

$$

LSZ265-251600-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
354 AM EDT Mon Sep 25 2017

.EARLY THIS MORNING...Southwest winds 10 to 20 knots. Waves 1 to
3 feet subsiding to calm to 2 feet.
.TODAY...Southwest winds 5 to 15 knots veering northwest in the
afternoon, then becoming north 10 to 20 knots late. A slight
chance of showers and thunderstorms by mid afternoon. Waves calm
to 2 feet.
.TONIGHT...North winds 10 to 20 knots diminishing to 5 to
15 knots after midnight, then veering northeast late. A chance of
showers and thunderstorms. 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.

$$

LSZ266-251600-
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-
354 AM EDT Mon Sep 25 2017

.EARLY THIS MORNING...South winds 10 to 20 knots. Waves 2 to
4 feet.
.TODAY...Southwest winds 5 to 15 knots veering west in the
afternoon, then veering north late. A slight chance of showers
and thunderstorms by mid afternoon. Waves 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. A chance of 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.

$$

LSZ267-251600-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
354 AM EDT Mon Sep 25 2017

.EARLY THIS MORNING...South winds 10 to 20 knots. Waves 1 to
3 feet.
.TODAY...South winds 10 to 20 knots becoming west 5 to 15 knots
in the afternoon, then veering north late. Waves subsiding to
calm to 2 feet.
.TONIGHT...North winds 5 to 15 knots veering northeast late. A
slight chance of 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.

$$

LSZ261-251600-
MAFOR 2509/
Superior West 12610 12700 11800 11116 11120 11136. Chance of
showers and thunderstorms early this morning...Then chance of
showers today. Chance of showers through early evening tonight.
Waves 2 feet or less today. Waves 2 feet or less building to 3 to
5 feet tonight.

Superior North Central 11510 11610 11600 11700 12810 12120.
Chance of showers and thunderstorms late in the evening. Chance
of showers overnight. Waves 1 to 4 feet.


Superior South Central 11410 11510 11600 11700 12810 11800 11110.
Chance of showers and thunderstorms through the early overnight...
Then chance of showers late tonight. Waves 1 to 3 feet.

Superior East 11410 12510 11600 13800 11110. Waves 2 to 4 feet
subsiding to 1 to 3 feet today. Waves 2 feet or less tonight.

$$

JLB

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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