Great Lakes Forecast
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FZUS63 KMQT 250758
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
358 AM 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 weak low pressure trough of 30.0 inches over the
lower Great Lakes will reach the East Coast by Thursday morning
while a 30.3 inch high pressure ridge over the Northern Plains
crosses the Upper Great Lakes. On Thursday, a low pressure trough
of 29.8 inches will cross Lake Superior. It will be quickly
followed by a secondary low of 30.1 inches on Friday. In its wake,
high pressure of 30.3 inches will settle over the western Great
Lakes Saturday and Sunday.

LSZ162-251600-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
358 AM EDT Wed Apr 25 2018 /258 AM CDT Wed Apr 25 2018/

.EARLY THIS MORNING...North winds less than 10 knots. Waves calm
to 2 feet.
.TODAY...North winds less than 10 knots becoming southwest 5 to
15 knots in the afternoon, then backing south late. Waves
building to 1 to 3 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest after
midnight. Waves subsiding to calm to 2 feet, then building to
1 to 3 feet.
.THURSDAY...West winds 5 to 15 knots veering north in the
afternoon. A slight chance of rain showers. Waves subsiding to
calm to 2 feet.
.THURSDAY NIGHT...Northwest winds 5 to 15 knots backing southwest
after midnight. A slight chance of snow showers after midnight.
Waves calm to 2 feet.
.FRIDAY...Southwest winds 5 to 15 knots becoming northwest 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...North winds 5 to 15 knots. Waves calm to 2 feet.
.SATURDAY...Southeast winds 5 to 15 knots veering south. Waves
calm to 2 feet.
.SUNDAY...South winds 5 to 15 knots increasing to 10 to 20 knots.
Waves building to 2 to 4 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-
358 AM EDT Wed Apr 25 2018

.EARLY THIS MORNING...North winds 5 to 15 knots. Waves 1 to
3 feet.
.TODAY...North winds 5 to 15 knots backing southwest in the
afternoon, then increasing to 10 to 20 knots late. Waves
subsiding to calm to 2 feet, then building to 1 to 3 feet.
.TONIGHT...Southwest winds 5 to 15 knots. Waves building to 2 to
4 feet.
.THURSDAY...West winds 10 to 20 knots becoming north 15 to
25 knots in the afternoon. A chance of rain showers. A chance of
snow showers by mid afternoon. Waves subsiding to 1 to 3 feet,
then building to 2 to 4 feet.
.THURSDAY NIGHT...North winds 10 to 20 knots becoming southwest
5 to 15 knots after midnight. A slight chance of snow showers
after midnight. Waves subsiding to calm to 2 feet.
.FRIDAY...South winds 5 to 15 knots backing southeast by mid
afternoon. A chance of snow showers, possibly mixed with rain.
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 veering south. Waves calm
to 2 feet.
.SUNDAY...South winds 5 to 15 knots increasing to 10 to 20 knots.
Waves building to 2 to 4 feet.

$$

LSZ264-251600-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
358 AM EDT Wed Apr 25 2018

.EARLY THIS MORNING...North winds 10 to 20 knots. Waves 2 to
4 feet.
.TODAY...North winds 5 to 15 knots backing west in the afternoon,
then increasing to 10 to 20 knots late. Waves subsiding to calm
to 2 feet, then building to 1 to 3 feet.
.TONIGHT...Southwest winds 10 to 20 knots increasing to 15 to
25 knots late. Waves 1 to 3 feet.
.THURSDAY...Southwest winds 15 to 25 knots veering north in the
afternoon, then increasing to 20 to 30 knots late. A chance of
rain showers, possibly mixed with snow by mid afternoon. Waves
building to 3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...North winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves subsiding to calm to 2 feet.
.FRIDAY...South winds 5 to 15 knots becoming southeast 10 to
20 knots by mid afternoon. A chance of snow showers, possibly
mixed with rain. Waves calm to 2 feet.
.FRIDAY NIGHT...North winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Waves calm to 2 feet.
.SATURDAY...North winds 5 to 15 knots backing southwest. Waves
calm to 2 feet.
.SUNDAY...South winds 10 to 20 knots becoming southwest 15 to
25 knots. Waves building to 3 to 5 feet occasionally to 7 feet,
then subsiding to 2 to 4 feet.

$$

LSZ265-251600-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
358 AM EDT Wed Apr 25 2018

.EARLY THIS MORNING...North winds 10 to 20 knots. Waves 3 to
5 feet occasionally to 7 feet.
.TODAY...North winds 10 to 20 knots. Waves subsiding to calm to
2 feet.
.TONIGHT...South winds 5 to 15 knots becoming southwest 10 to
20 knots after midnight. Waves calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots veering northwest in
the afternoon, then increasing to 20 to 30 knots late. A chance
of rain showers, possibly mixed with snow by mid afternoon. Waves
building to 3 to 5 feet occasionally to 7 feet.
.THURSDAY NIGHT...North winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. A slight chance of rain and snow showers
through midnight. Waves subsiding to 1 to 3 feet.
.FRIDAY...Southwest winds 5 to 15 knots backing east by mid
afternoon. A chance of rain and snow showers. Waves subsiding to
calm to 2 feet.
.FRIDAY NIGHT...North winds 5 to 15 knots becoming northwest
10 to 20 knots after midnight. Waves calm to 2 feet.
.SATURDAY...North winds 10 to 20 knots becoming southwest 5 to
15 knots. Waves calm to 2 feet.
.SUNDAY...South winds 10 to 20 knots becoming southwest 15 to
25 knots. Waves building 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-
358 AM EDT Wed Apr 25 2018

.EARLY THIS MORNING...North winds 15 to 25 knots. Waves 3 to
6 feet occasionally to 8 feet, then subsiding to 3 to 5 feet
occasionally to 7 feet.
.TODAY...North winds 10 to 20 knots becoming northwest 5 to
15 knots late. Waves subsiding to 1 to 3 feet.
.TONIGHT...Southwest winds 5 to 15 knots backing south after
midnight, then increasing to 10 to 20 knots late. Waves 1 to
3 feet.
.THURSDAY...South winds 10 to 20 knots veering southwest in the
afternoon, then becoming northwest 15 to 25 knots late. A slight
chance of rain showers, possibly mixed with snow by mid
afternoon. Waves building to 3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...North winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. 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 5 to 15 knots. Waves subsiding to calm to
2 feet.
.FRIDAY NIGHT...North winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Waves calm to 2 feet.
.SATURDAY...North winds 10 to 20 knots becoming west 5 to
15 knots. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.
.SUNDAY...South winds 10 to 20 knots increasing to 15 to
25 knots. Waves building to 3 to 6 feet occasionally to 8 feet.

$$

LSZ267-251600-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
358 AM EDT Wed Apr 25 2018

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

$$

LSZ261-251600-
MAFOR 2509/
Superior West 11800 11700 12510 12410 12520. Waves 2 feet or less
today. Waves 1 to 3 feet tonight.

Superior North Central 11820 11810 11700 11610 11620 13520. Waves
2 to 4 feet subsiding to 1 to 3 feet today. Waves 1 to 3 feet
tonight.

Superior South Central 12820 12810 11100 11300 12410. Waves 3 to
5 feet subsiding to 2 to 4 feet today. Waves 1 to 2 feet tonight.

Superior East 12820 11810 11720 11710 11610 12500. Waves 2 to 4
feet subsiding to 1 to 3 feet today. Waves 1 to 3 feet tonight.

$$

JLA

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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