Great Lakes Forecast
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FZUS63 KMQT 260202
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1002 PM EDT Wed Apr 25 2018

For waters beyond 5 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...A ridge of 30.0 inches will exit the Upper Great
Lakes overnight, followed by a weak trough of 29.8 inches on
Thursday. On Friday, a low of 29.8 inches will track across the
Upper Great Lakes region. This low will track into Quebec and
merge with another area of low pressure, deepening to 29.3 inches
on Saturday. Behind this low pressure system, high pressure of
30.0 inches will drop into the northern Plains. By Sunday, this
high pressure will strengthen to 30.3 inches as it tracks across
the region.

LSZ162-261015-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1002 PM EDT Wed Apr 25 2018 /902 PM CDT Wed Apr 25 2018/

.REST OF TONIGHT...South winds 5 to 15 knots veering southwest
after midnight. Waves calm to 2 feet building to 1 to 3 feet.
.THURSDAY...Southwest winds 5 to 15 knots veering northwest in
the afternoon. A slight chance of rain showers. Waves subsiding
to calm to 2 feet.
.THURSDAY NIGHT...North winds 5 to 15 knots becoming northeast
less than 10 knots after midnight, then becoming southeast 5 to
15 knots late. A chance of snow showers, possibly mixed with rain
after midnight. Waves calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots backing northeast by mid
afternoon. Snow showers likely through early afternoon. A chance
of rain showers. Waves calm to 2 feet.
.FRIDAY NIGHT...Northwest winds 5 to 15 knots veering north after
midnight. Waves calm to 2 feet.
.SATURDAY...Northeast winds 5 to 15 knots veering south by mid
afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...South winds less than 10 knots. Waves calm to
2 feet.
.SUNDAY...South winds 5 to 15 knots increasing to 10 to 20 knots.
A chance of rain showers. Waves building to 2 to 4 feet.
.MONDAY...South winds 5 to 15 knots becoming southeast 10 to
20 knots. A chance of rain showers. Waves subsiding to calm to
2 feet, then building to 1 to 3 feet.

$$

LSZ263-261015-
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-
1002 PM EDT Wed Apr 25 2018

.REST OF TONIGHT...South winds 5 to 15 knots veering southwest
late. Waves calm to 2 feet building to 1 to 3 feet.
.THURSDAY...Southwest winds 10 to 20 knots veering northwest in
the afternoon, then veering north late. A chance of rain showers.
Waves 1 to 3 feet.
.THURSDAY NIGHT...North winds 5 to 15 knots veering east late. A
slight chance of snow showers after midnight. Waves subsiding to
calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots backing northeast by mid
afternoon. Snow showers, possibly mixed with rain through early
afternoon, then a slight chance of rain and snow showers by mid
afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...North winds 5 to 15 knots. Waves calm to 2 feet.
.SATURDAY...North winds 5 to 15 knots backing southwest by mid
afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Southwest winds less than 10 knots increasing
to 5 to 15 knots after midnight. Waves calm to 2 feet.
.SUNDAY...Southwest winds 5 to 15 knots becoming south 10 to
20 knots. Waves building to 2 to 4 feet.
.MONDAY...South winds 5 to 15 knots becoming southeast 10 to
20 knots. A chance of rain showers. Waves subsiding to calm to
2 feet, then building to 1 to 3 feet.

$$

LSZ264-261015-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1002 PM EDT Wed Apr 25 2018

.REST OF TONIGHT...South winds 10 to 20 knots veering southwest
late. Waves 1 to 3 feet.
.THURSDAY...Southwest winds 10 to 20 knots becoming northwest
15 to 25 knots in the afternoon, then veering north late. A
chance of rain showers. A slight chance of snow showers by mid
afternoon. Waves building to 3 to 5 feet occasionally to 7 feet.
.THURSDAY NIGHT...North winds 10 to 20 knots becoming northeast
5 to 15 knots late. Waves subsiding to calm to 2 feet.
.FRIDAY...Northeast winds 5 to 15 knots backing north by mid
afternoon. A slight chance of snow showers. A slight chance of
rain showers by mid afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...North winds 10 to 20 knots veering northeast
after midnight. Waves calm to 2 feet.
.SATURDAY...North winds 10 to 20 knots becoming west 5 to
15 knots by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...West winds 5 to 15 knots backing southwest
after midnight. Waves calm to 2 feet.
.SUNDAY...Southwest winds 10 to 20 knots. Waves building to 3 to
5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet.
.MONDAY...South winds 10 to 20 knots increasing to 15 to
25 knots. A chance of rain showers. Waves subsiding to 1 to
3 feet, then building to 2 to 4 feet.

$$

LSZ265-261015-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1002 PM EDT Wed Apr 25 2018

.REST OF TONIGHT...South winds 5 to 15 knots increasing to 10 to
20 knots late. Waves calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots becoming west 5 to
15 knots in the afternoon, then becoming northwest 15 to 25 knots
late. A chance of rain showers, possibly mixed with snow by mid
afternoon. Waves building to 2 to 4 feet.
.THURSDAY NIGHT...North winds 15 to 25 knots diminishing to 5 to
15 knots. Waves subsiding to 1 to 3 feet.
.FRIDAY...North winds 5 to 15 knots increasing to 10 to 20 knots
by mid afternoon. A slight chance of rain and snow showers. Waves
subsiding to calm to 2 feet.
.FRIDAY NIGHT...North winds 10 to 20 knots. Waves calm to 2 feet.
.SATURDAY...North winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Northwest winds 5 to 15 knots backing west
after midnight. Waves calm to 2 feet.
.SUNDAY...Southeast winds 5 to 15 knots becoming southwest 10 to
20 knots. Waves building to 1 to 3 feet.
.MONDAY...South winds 10 to 20 knots. A chance of showers. Waves
subsiding to calm to 2 feet, then building to 1 to 3 feet.

$$

LSZ266-261015-
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-
1002 PM EDT Wed Apr 25 2018

.REST OF TONIGHT...South winds 5 to 15 knots increasing to 10 to
20 knots late. Waves calm to 2 feet building to 1 to 3 feet.
.THURSDAY...South winds 10 to 20 knots becoming northwest 15 to
25 knots late. A slight chance of rain and snow showers by mid
afternoon. Waves building to 3 to 5 feet occasionally to 7 feet.
.THURSDAY NIGHT...North winds 15 to 25 knots diminishing to 10 to
20 knots late. A slight chance of rain and snow showers through
midnight. Waves building to 4 to 7 feet occasionally to 9 feet,
then subsiding to 2 to 4 feet.
.FRIDAY...North winds 10 to 20 knots. A slight chance of rain and
snow showers by mid afternoon. Waves subsiding to calm to 2 feet.
.FRIDAY NIGHT...North winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Waves calm to 2 feet.
.SATURDAY...North winds 15 to 25 knots becoming northwest 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Northwest winds 5 to 15 knots. Waves building
to 1 to 3 feet, then subsiding to calm to 2 feet.
.SUNDAY...South winds 5 to 15 knots increasing to 15 to 25 knots.
Waves building to 3 to 6 feet occasionally to 8 feet.
.MONDAY...South winds 15 to 25 knots. A chance of rain showers.
Waves subsiding to 1 to 3 feet, then building to 3 to 5 feet
occasionally to 7 feet.

$$

LSZ267-261015-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1002 PM EDT Wed Apr 25 2018

.REST OF TONIGHT...West winds 5 to 15 knots backing south late.
Waves calm to 2 feet.
.THURSDAY...South winds 10 to 20 knots diminishing to 5 to
15 knots in the afternoon, then veering west late. A slight
chance of rain showers by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Northwest winds 15 to 25 knots veering north
after midnight, then diminishing to 10 to 20 knots late. A slight
chance of rain and snow showers through midnight. Waves building
to 3 to 6 feet occasionally to 8 feet, then subsiding to 2 to
4 feet.
.FRIDAY...North winds 10 to 20 knots. Waves subsiding to calm to
2 feet.
.FRIDAY NIGHT...North winds 15 to 25 knots. Waves building to 1
to 3 feet.
.SATURDAY...North winds 15 to 25 knots backing northwest by mid
afternoon. Waves 2 to 4 feet.
.SATURDAY NIGHT...Northwest winds 10 to 20 knots becoming north
5 to 15 knots after midnight. Waves subsiding to calm to 2 feet.
.SUNDAY...West winds 5 to 15 knots becoming south 10 to 20 knots.
Waves building to 2 to 4 feet.
.MONDAY...South winds 10 to 20 knots increasing to 15 to
25 knots. A chance of rain showers. Waves subsiding to 1 to
3 feet, then building to 3 to 5 feet occasionally to 7 feet.

$$
LSZ261-261015-
MAFOR 2603/
Superior West 11410 11510 12520 11620 11820 12700. Waves 1 to 3
feet.

Superior North Central 12410 12520 11620 11720 11830 11820.
Chance of rain showers late Thursday and Thursday evening. Waves
1 to 4 feet.

Superior South Central 11400 13410 11510 11620 12730. Chance of
rain showers late Thursday, then chance of rain and snow showers
early Thursday evening. Waves 1 to 5 feet.

Superior East 11500 11510 13410 11500 11620 11730. Waves 1 to 4
feet.

$$

Petro

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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