Great Lakes Forecast
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FZUS63 KMQT 180201
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 PM EDT Thu Aug 17 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 29.5 inches over central Upper
Michigan will track across easter Upper Michigan tonight
and reach southwest Quebec Friday night. In its wake, high
pressure of 30.0 inches will shift east to the western Great Lakes
late Friday and then expand over the Great Lakes region Saturday
into Sunday. On Sunday afternoon a 29.9 inch trough moves into
western Lake Superior and then tracks east through Sunday night. A
30.1 inch high pressure ridge follows on Monday while a 29.8 inch
low moves across the Upper Great Lakes on Tuesday.

LSZ162-181015-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 PM EDT Thu Aug 17 2017 /901 PM CDT Thu Aug 17 2017/

.REST OF TONIGHT...North winds 15 to 25 knots backing northwest
after midnight. Isolated showers by late evening. Waves 3 to
6 feet occasionally to 8 feet subsiding to 2 to 4 feet, then
building to 3 to 5 feet occasionally to 7 feet.
.FRIDAY...Northwest winds 10 to 20 knots backing west in the
afternoon. Waves subsiding to calm to 2 feet.
.FRIDAY NIGHT...West winds 5 to 15 knots. A chance of showers
through midnight. Waves calm to 2 feet.
.SATURDAY...West winds 5 to 15 knots becoming southwest 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Southwest winds 10 to 20 knots. Waves calm to
2 feet.
.SUNDAY...Southwest winds 10 to 20 knots. Waves calm to 2 feet.
.SUNDAY NIGHT...West winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.MONDAY...East winds 5 to 15 knots backing northwest. A chance of
showers. Waves calm to 2 feet.
.TUESDAY...West winds 5 to 15 knots becoming northwest 10 to
20 knots. Waves calm to 2 feet.

$$

LSZ263-181015-
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-
1001 PM EDT Thu Aug 17 2017

.REST OF TONIGHT...North winds 20 to 30 knots diminishing to
15 to 25 knots after midnight, then backing northwest late.
Patchy fog. Scattered showers. Waves 5 to 8 feet occasionally to
10 feet subsiding to 3 to 5 feet occasionally to 7 feet.
.FRIDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots in the afternoon, then diminishing to 5 to 15 knots
late. Waves subsiding to 1 to 3 feet.
.FRIDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm
to 2 feet.
.SATURDAY...West winds 5 to 15 knots backing southwest by mid
afternoon. Waves building to 1 to 3 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots. Waves 1 to
3 feet.
.SUNDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.SUNDAY NIGHT...West winds 5 to 15 knots. A chance of
thunderstorms through midnight. A chance of showers. Waves calm
to 2 feet.
.MONDAY...West winds 5 to 15 knots. Waves calm to 2 feet.
.TUESDAY...West winds 5 to 15 knots veering northwest. Waves calm
to 2 feet.

$$

LSZ264-181015-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 PM EDT Thu Aug 17 2017

.REST OF TONIGHT...Northeast winds 15 to 25 knots backing north
after midnight. Patchy fog. Showers and isolated thunderstorms by
late evening. Scattered showers after midnight. Waves 5 to 8 feet
occasionally to 10 feet subsiding to 3 to 5 feet occasionally to
7 feet.
.FRIDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots late. Patchy fog through early afternoon. A slight
chance of showers through early afternoon. Waves subsiding to
2 to 4 feet.
.FRIDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm
to 2 feet.
.SATURDAY...West winds 5 to 15 knots backing southwest by mid
afternoon. Waves building to 1 to 3 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots. Waves 1 to
3 feet.
.SUNDAY...Southwest winds 5 to 15 knots. A chance of showers and
thunderstorms by mid afternoon. Waves 1 to 3 feet.
.SUNDAY NIGHT...Southwest winds 5 to 15 knots veering west after
midnight. A chance of thunderstorms through midnight. A chance of
showers. Waves subsiding to calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.TUESDAY...West winds 5 to 15 knots veering northwest. Waves
building to 1 to 3 feet.

$$

LSZ265-181015-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 PM EDT Thu Aug 17 2017

.REST OF TONIGHT...North winds 10 to 20 knots becoming northwest
15 to 25 knots after midnight, then increasing to 20 to 30 knots
late. Areas of fog. Numerous showers and isolated thunderstorms
by late evening. Scattered showers after midnight. Waves 3 to
5 feet occasionally to 7 feet.
.FRIDAY...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots late. Patchy fog through early afternoon. A slight
chance of showers through early afternoon. Waves building to 3 to
6 feet occasionally to 8 feet, then subsiding to 2 to 4 feet.
.FRIDAY NIGHT...Northwest winds 10 to 20 knots backing west after
midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...West winds 10 to 20 knots. Waves calm to 2 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots increasing to
10 to 20 knots after midnight. Waves calm to 2 feet.
.SUNDAY...Southwest winds 10 to 20 knots backing south by mid
afternoon. A chance of showers and thunderstorms by mid
afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...Southwest winds 10 to 20 knots veering west after
midnight. A chance of thunderstorms through midnight. A chance of
showers. Waves calm to 2 feet.
.MONDAY...Southwest winds 10 to 20 knots veering west. A chance
of showers and thunderstorms. Waves calm to 2 feet.
.TUESDAY...West winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ266-181015-
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-
1001 PM EDT Thu Aug 17 2017

.REST OF TONIGHT...East winds 10 to 20 knots increasing to 15 to
25 knots after midnight, then becoming northwest 20 to 30 knots
late. Areas of fog. Scattered thunderstorms by late evening.
Scattered showers. Waves 3 to 6 feet occasionally to 8 feet.
.FRIDAY...Northwest winds 15 to 25 knots increasing to 20 to
30 knots in the afternoon, then diminishing to 15 to 25 knots
late. Patchy fog through early afternoon. A slight chance of
showers through early afternoon. Waves 3 to 6 feet occasionally
to 8 feet.
.FRIDAY NIGHT...Northwest winds 15 to 25 knots diminishing to
10 to 20 knots after midnight, then backing west late. Waves
subsiding to 1 to 3 feet.
.SATURDAY...West winds 5 to 15 knots. Waves subsiding to calm to
2 feet, then building to 1 to 3 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots increasing to
10 to 20 knots after midnight. Waves 1 to 3 feet.
.SUNDAY...Southwest winds 10 to 20 knots backing south by mid
afternoon. A chance of showers and thunderstorms by mid
afternoon. Waves subsiding to calm to 2 feet.
.SUNDAY NIGHT...Southwest winds 10 to 20 knots. A chance of
showers and thunderstorms. Waves calm to 2 feet.
.MONDAY...Southwest winds 10 to 20 knots veering west. A chance
of showers and thunderstorms. Waves calm to 2 feet.
.TUESDAY...West winds 10 to 20 knots veering northwest. A chance
of showers. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.

$$

LSZ267-181015-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 PM EDT Thu Aug 17 2017

.REST OF TONIGHT...Southeast winds 15 to 25 knots diminishing to
10 to 20 knots after midnight, then becoming southwest 5 to
15 knots late. Patchy fog. Scattered thunderstorms by late
evening. Scattered showers. Waves 3 to 5 feet occasionally to
7 feet subsiding to calm to 2 feet.
.FRIDAY...Northwest winds 10 to 20 knots increasing to 20 to
30 knots. Patchy fog through early afternoon. A chance of
showers. Waves building to 3 to 6 feet occasionally to 8 feet.
.FRIDAY NIGHT...Northwest winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. A slight chance of showers through
midnight. Waves subsiding to 1 to 3 feet.
.SATURDAY...West winds 10 to 20 knots. Waves subsiding to calm to
2 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots increasing to
10 to 20 knots after midnight. Waves calm to 2 feet.
.SUNDAY...Southwest winds 5 to 15 knots becoming south 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight. A chance of showers and thunderstorms. Waves
building to 1 to 3 feet, then subsiding to calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots. A chance of showers and thunderstorms. Waves calm to
2 feet.
.TUESDAY...West winds 10 to 20 knots veering northwest. A chance
of showers. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.

$$
LSZ261-181015-
MAFOR 1803/
Superior West 12730 11720 11730 12620 12610. Waves 1 to 5 feet.

Superior North Central 11136 12830 13730 11720 11710. Patchy fog
through late Friday morning. Scattered showers late overnight.
Waves 5 to 8 feet overnight subsiding to 3 to 6 feet Friday.
Waves subsiding to 1 to 4 feet on Friday evening.

Superior South Central 11826 11736 14740 11730 11720. Patchy fog
through Friday afternoon. Scattered showers through mid Friday
morning. Waves 2 to 6 feet.

Superior East 11320 11213 11110 14730 11730. Patchy fog late this
evening through early Friday afternoon. Scattered showers
overnight through late Friday morning. Waves 2 to 6 feet.


$$

JSS

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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