Great Lakes Forecast
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FZUS63 KMQT 170755
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
355 AM 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 29.6 inches over eastern Minnesota
will track across the Upper Great Lakes today 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.

LSZ162-171600-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
355 AM EDT Thu Aug 17 2017 /255 AM CDT Thu Aug 17 2017/

.EARLY THIS MORNING...Northeast winds 15 to 25 knots. Patchy fog.
Showers likely and a slight chance of thunderstorms. Waves 4 to
7 feet occasionally to 9 feet.
.TODAY...Northeast winds 20 to 30 knots diminishing to 15 to
25 knots in the afternoon, then backing north late. Patchy fog.
Showers likely through early afternoon. A chance of
thunderstorms. A chance of showers by mid afternoon. Waves
building to 5 to 8 feet occasionally to 10 feet, then subsiding
to 3 to 6 feet occasionally to 8 feet.
.TONIGHT...North winds 20 to 30 knots diminishing to 15 to
25 knots after midnight, then backing northwest late. Patchy fog.
A chance of showers. Waves subsiding to 2 to 4 feet.
.FRIDAY...Northwest winds 10 to 20 knots backing west in the
afternoon, then diminishing to 5 to 15 knots late. Waves
subsiding to calm to 2 feet.
.FRIDAY NIGHT...West winds 5 to 15 knots. 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 diminishing to 5 to
15 knots. A chance of showers. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots veering northwest. A
chance of showers and thunderstorms. Waves calm to 2 feet.

$$

LSZ263-171600-
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-
355 AM EDT Thu Aug 17 2017

.EARLY THIS MORNING...East winds 15 to 25 knots. Patchy fog.
Showers likely and a slight chance of thunderstorms. Waves 2 to
4 feet building to 3 to 5 feet occasionally to 7 feet.
.TODAY...East winds 15 to 25 knots backing northeast late. Patchy
fog. Showers likely through early afternoon. A chance of
thunderstorms. A chance of showers by mid afternoon. Waves
building to 5 to 8 feet occasionally to 10 feet.
.TONIGHT...Northeast winds 15 to 25 knots backing north after
midnight. Patchy fog. A slight chance of thunderstorms through
midnight. A chance of showers. Waves building to 6 to 9 feet
occasionally to 11 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.FRIDAY...Northwest winds 10 to 20 knots backing west in the
afternoon, then diminishing to 5 to 15 knots late. A slight
chance of showers through early afternoon. Waves subsiding to
calm to 2 feet.
.FRIDAY NIGHT...West winds 5 to 15 knots. Waves calm to 2 feet.
.SATURDAY...West winds 5 to 15 knots backing southwest by mid
afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.SUNDAY...Southwest winds 5 to 15 knots. A chance of showers and
thunderstorms. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots veering west. A chance of
showers. Waves calm to 2 feet.

$$

LSZ264-171600-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
355 AM EDT Thu Aug 17 2017

.EARLY THIS MORNING...East winds 10 to 20 knots. A chance of
showers. Waves 1 to 3 feet building to 2 to 4 feet.
.TODAY...East winds 20 to 30 knots. Patchy fog. Showers likely
and a chance of thunderstorms. Waves building to 6 to 9 feet
occasionally to 11 feet.
.TONIGHT...East winds 15 to 25 knots becoming northeast 10 to
20 knots after midnight, then backing north late. Patchy fog.
Showers likely and a slight chance of thunderstorms through
midnight. A chance of showers after midnight. Waves subsiding to
3 to 6 feet occasionally to 8 feet.
.FRIDAY...North winds 10 to 20 knots backing northwest in the
afternoon. A 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. Waves calm to 2 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.SUNDAY...Southwest winds 5 to 15 knots. Waves building to 1 to
3 feet, then subsiding to calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.

$$

LSZ265-171600-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
355 AM EDT Thu Aug 17 2017

.EARLY THIS MORNING...East winds 15 to 25 knots. Showers likely.
Waves 1 to 3 feet building to 2 to 4 feet.
.TODAY...East winds 20 to 30 knots diminishing to 10 to 20 knots.
Patchy fog. Showers and a chance of thunderstorms. Waves building
to 5 to 8 feet occasionally to 10 feet.
.TONIGHT...East winds 5 to 15 knots becoming north 10 to 20 knots
after midnight, then increasing to 15 to 25 knots late. Patchy
fog. A slight chance of thunderstorms through midnight. Showers
likely. Waves subsiding to 3 to 5 feet occasionally to 7 feet.
.FRIDAY...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots late. A 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...West winds 10 to 20 knots. Waves subsiding to
calm to 2 feet.
.SATURDAY...West winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. 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...South winds 10 to 20 knots veering southwest. A chance
of showers. Waves calm to 2 feet.
.MONDAY...Southwest winds 10 to 20 knots. A chance of showers and
thunderstorms. Waves calm to 2 feet.

$$

LSZ266-171600-
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-
355 AM EDT Thu Aug 17 2017

.EARLY THIS MORNING...East winds 15 to 25 knots. Showers likely.
Waves 1 to 3 feet building to 2 to 4 feet.
.TODAY...East winds 20 to 30 knots veering southeast in the
afternoon, then backing east late. Patchy fog. Showers likely and
a chance of thunderstorms. Waves building to 5 to 9 feet
occasionally to 11 feet.
.TONIGHT...East winds 15 to 25 knots diminishing to 10 to
20 knots after midnight, then backing north late. Patchy fog. A
slight chance of thunderstorms through midnight. Showers likely.
Waves subsiding to 3 to 5 feet occasionally to 7 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. A chance of showers through early afternoon. Waves building
to 4 to 7 feet occasionally to 9 feet, then subsiding to 3 to
6 feet occasionally to 8 feet.
.FRIDAY NIGHT...Northwest winds 10 to 20 knots backing west after
midnight. Waves subsiding to 1 to 3 feet.
.SATURDAY...West winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. 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...South winds 10 to 20 knots veering southwest. A chance
of showers. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.
.MONDAY...Southwest winds 10 to 20 knots. A chance of showers and
thunderstorms. Waves calm to 2 feet.

$$

LSZ267-171600-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
355 AM EDT Thu Aug 17 2017

.EARLY THIS MORNING...Southeast winds 20 to 30 knots. A chance of
showers. Waves 1 to 3 feet building to 2 to 4 feet.
.TODAY...Southeast winds 20 to 30 knots with a few gale force
gusts to 35 knots. Patchy fog. Showers and a slight chance of
thunderstorms. Waves building to 4 to 7 feet occasionally to 9
feet.
.TONIGHT...Southeast winds 15 to 25 knots becoming east 10 to
20 knots after midnight, then diminishing to 5 to 15 knots late.
Patchy fog. Showers likely and a slight chance of thunderstorms.
Waves subsiding to 1 to 3 feet.
.FRIDAY...Northwest winds 10 to 20 knots increasing to 20 to
30 knots. 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. Waves calm to
2 feet.
.SUNDAY...South winds 5 to 15 knots becoming southwest 10 to
20 knots. A chance of showers. Waves building to 1 to 3 feet,
then subsiding to calm to 2 feet.
.MONDAY...Southwest winds 10 to 20 knots. A chance of showers and
thunderstorms. Waves calm to 2 feet.

$$

LSZ261-171600-
MAFOR 1709/
Superior West 11136 12146 12130 13830. Patchy fog. Chance of
thunderstorms early this afternoon. Chance of showers late today
and tonight. Waves 3 to 7 feet.

Superior North Central 11220 11236 13246 11236 11126 11120.
Patchy fog. Chance of thunderstorms late today through early
evening. Chance of showers late tonight. Waves 2 to 4 feet
building to 5 to 8 feet today. Waves 5 to 9 feet tonight.

Superior South Central 11226 12246 11230 11226 12216 11826.
Patchy fog. Chance of showers early this morning. Chance of
showers and thunderstorms this afternoon through this evening.
Chance of showers after midnight tonight. Waves 2 to 4 feet
building to 4 to 7 feet today. Waves subsiding to 3 to 6 feet
tonight.

Superior East 11330 14346 11236 11226 11216. Patchy fog from late
morning on. Chance of thunderstorms late today. Waves 2 to 3 feet
building to 5 to 8 feet today. Waves subsiding to 3 to 5 feet
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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