Great Lakes Forecast
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FZUS63 KMQT 180808
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
408 AM EDT Fri Aug 18 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 located in eastern Upper
Michigan will continue to lift into southwest Quebec by tonight.
In its wake, high pressure of 29.9 inches will shift east to the
western Great Lakes and then expand southward over the Ohio River
Valley Saturday into Sunday. On Sunday afternoon a 29.8 inch
trough moves into western Lake Superior and then tracks east
through Sunday night. This trough will stall out across the Upper
Great Lakes through Monday, followed by a 30.0 inch area of high
pressure dropping south across the Upper Mississippi Valley on
Tuesday.

LSZ162-181615-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
408 AM EDT Fri Aug 18 2017 /308 AM CDT Fri Aug 18 2017/

.EARLY THIS MORNING...Northwest winds 10 to 20 knots. Waves 2 to
4 feet.
.TODAY...Northwest winds 5 to 15 knots backing west in the
afternoon. Waves subsiding to calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots. A slight chance of showers
and isolated thunderstorms through midnight. Waves calm to
2 feet.
.SATURDAY...West winds 10 to 20 knots backing southwest in the
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 building to 1 to
3 feet, then subsiding to calm to 2 feet.
.SUNDAY NIGHT...West winds 5 to 15 knots veering northwest after
midnight. A chance of showers. Waves calm to 2 feet.
.MONDAY...Northeast winds 5 to 15 knots backing north. Waves calm
to 2 feet.
.TUESDAY...Northwest winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ263-181615-
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-
408 AM EDT Fri Aug 18 2017

.EARLY THIS MORNING...Northwest winds 15 to 25 knots. Patchy fog.
Waves 3 to 5 feet occasionally to 7 feet.
.TODAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots in the afternoon, then diminishing to 5 to 15 knots
late. Patchy fog through early afternoon. Waves subsiding to 1 to
3 feet.
.TONIGHT...West winds 5 to 15 knots. A slight chance of showers
through midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...West winds 5 to 15 knots backing southwest in the
afternoon. Waves building to 1 to 3 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots. Waves subsiding
to calm to 2 feet, then building to 1 to 3 feet.
.SUNDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots by mid afternoon. Waves 1 to 3 feet.
.SUNDAY NIGHT...West winds 5 to 15 knots. A chance of showers.
Waves subsiding to calm to 2 feet.
.MONDAY...Northeast winds 5 to 15 knots backing northwest. Waves
calm to 2 feet.
.TUESDAY...Northwest winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ264-181615-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
408 AM EDT Fri Aug 18 2017

.EARLY THIS MORNING...North winds 15 to 25 knots. Patchy fog. A
slight chance of showers. Waves 3 to 6 feet occasionally to
8 feet.
.TODAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots late. Patchy fog through early afternoon. Waves
subsiding to 2 to 4 feet.
.TONIGHT...West winds 10 to 20 knots diminishing to 5 to 15 knots
after midnight. A slight chance of showers through midnight.
Waves subsiding to calm to 2 feet.
.SATURDAY...West winds 5 to 15 knots backing southwest in the
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. Waves 1 to 3 feet.
.SUNDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm
to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots veering west. Waves calm
to 2 feet.
.TUESDAY...West winds 5 to 15 knots veering northwest. A chance
of showers. Waves calm to 2 feet.

$$

LSZ265-181615-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
408 AM EDT Fri Aug 18 2017

.EARLY THIS MORNING...Northwest winds 20 to 30 knots. Areas of
fog. A chance of showers. Waves 3 to 6 feet occasionally to
8 feet.
.TODAY...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots late. A slight chance of showers through early
afternoon. Patchy fog. Waves subsiding to 2 to 4 feet.
.TONIGHT...Northwest winds 10 to 20 knots backing west after
midnight. A slight chance of showers through midnight. Waves
subsiding to calm to 2 feet.
.SATURDAY...West winds 5 to 15 knots increasing to 10 to 20 knots
late. 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 backing south by mid
afternoon. A chance of showers by mid afternoon. Waves calm to
2 feet.
.SUNDAY NIGHT...Southwest winds 10 to 20 knots becoming west 5 to
15 knots after midnight. A chance of showers. Waves calm to
2 feet.
.MONDAY...West winds 5 to 15 knots. Waves calm to 2 feet.
.TUESDAY...North winds 10 to 20 knots backing northwest. A chance
of showers. Waves calm to 2 feet.

$$

LSZ266-181615-
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-
408 AM EDT Fri Aug 18 2017

.EARLY THIS MORNING...Northwest winds 20 to 30 knots. Widespread
fog. A chance of showers. Waves 3 to 6 feet occasionally to
8 feet.
.TODAY...Northwest winds 20 to 30 knots. Areas of fog. A chance
of showers. Waves building to 4 to 7 feet occasionally to 9 feet.
.TONIGHT...Northwest winds 10 to 20 knots backing west late. A
slight chance of showers through midnight. 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. Waves 1 to 3 feet.
.SUNDAY NIGHT...Southwest winds 10 to 20 knots becoming west 5 to
15 knots after midnight. A chance of showers. Waves subsiding to
calm to 2 feet, then building to 1 to 3 feet.
.MONDAY...West winds 5 to 15 knots. A chance of showers. Waves
calm to 2 feet.
.TUESDAY...North winds 10 to 20 knots backing northwest. A chance
of showers. Waves building to 1 to 3 feet.

$$

LSZ267-181615-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
408 AM EDT Fri Aug 18 2017

.EARLY THIS MORNING...West winds 5 to 15 knots. Areas of fog. A
chance of showers. Waves calm to 2 feet.
.TODAY...Northwest winds 15 to 25 knots increasing to 20 to 30
knots. Patchy fog. A chance of showers. Waves building to 4 to 7
feet occasionally to 9 feet.
.TONIGHT...Northwest winds 20 to 30 knots diminishing to 10 to
20 knots. A slight chance of showers through midnight. Patchy fog
after midnight. Waves subsiding to 1 to 3 feet.
.SATURDAY...West winds 10 to 20 knots diminishing to 5 to
15 knots late. Patchy fog through early afternoon. Waves
subsiding to calm to 2 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots. 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 becoming southwest
5 to 15 knots after midnight. A chance of showers. Waves calm to
2 feet.
.MONDAY...Southwest winds 5 to 15 knots veering north. A chance
of showers. Waves calm to 2 feet.
.TUESDAY...North winds 10 to 20 knots backing northwest. A chance
of showers. Waves calm to 2 feet.

$$

LSZ261-181615-
MAFOR 1809/

Superior West 12720 12620 14610. Waves 1 to 4 feet.

Superior North Central 11830 13730 12720 11610 11600. Patchy fog
through late morning. Waves 1 to 6 feet.

Superior South Central 12743 12740 11730 11720 11710 11610.
Patchy fog through this afternoon. Chance of showers this
morning. Waves 1 to 6 feet.

Superior East 11113 11733 11740 14730 11720. Patchy fog through
late tonight. Chance of showers. Waves 2 to 7 feet.

$$

Ritzman

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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