Great Lakes Forecast
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FZUS63 KMQT 182002
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
402 PM 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 over Ontario will reach
southwest Quebec tonight. High pressure of 29.9 inches will reach
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 and move over the eastern Great lakes Tuesday.
A 30.0 inch area of high pressure will drop south across the
Upper Mississippi Valley on Tuesday. 30.2 inch high pressure over
the Canadian Prairies Tuesday morning will reach the western Great
Lakes by Wednesday evening.

LSZ162-190415-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
402 PM EDT Fri Aug 18 2017 /302 PM CDT Fri Aug 18 2017/

.LATE THIS AFTERNOON...Southwest winds 5 to 15 knots. Waves calm
to 2 feet.
.TONIGHT...West winds 5 to 15 knots. Isolated showers through
midnight. Waves calm to 2 feet.
.SATURDAY...West winds 5 to 15 knots backing southwest in the
afternoon, then increasing to 10 to 20 knots late. Waves building
to 1 to 3 feet, then subsiding to calm to 2 feet.
.SATURDAY NIGHT...Southwest winds 10 to 20 knots. Waves calm to
2 feet.
.SUNDAY...Southwest winds 10 to 20 knots. A slight chance of
showers. A slight chance of thunderstorms by mid afternoon. 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. Waves calm to 2 feet.
.MONDAY...Northeast winds 5 to 15 knots veering east by mid
afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...Northeast winds 5 to 15 knots backing north after
midnight. Waves calm to 2 feet.
.TUESDAY...Northwest winds 10 to 20 knots. Waves building to 1 to
3 feet.
.WEDNESDAY...North winds 10 to 20 knots becoming northeast 5 to
15 knots. Waves subsiding to calm to 2 feet.

$$

LSZ263-190415-
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-
402 PM EDT Fri Aug 18 2017

.LATE THIS AFTERNOON...West winds 5 to 15 knots. Waves 1 to
3 feet.
.TONIGHT...West winds 5 to 15 knots. 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 10 to 20 knots. A slight chance of
showers. A slight chance of thunderstorms by mid afternoon. Waves
building to 2 to 4 feet, then subsiding to 1 to 3 feet.
.SUNDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm
to 2 feet.
.MONDAY...Northwest winds less than 10 knots veering northeast by
mid afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...Northeast winds less than 10 knots becoming north
5 to 15 knots after midnight. Waves calm to 2 feet.
.TUESDAY...Northwest winds 5 to 15 knots increasing to 10 to
20 knots. Waves building to 1 to 3 feet.
.WEDNESDAY...North winds 5 to 15 knots. Waves subsiding to calm
to 2 feet.

$$

LSZ264-190415-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
402 PM EDT Fri Aug 18 2017

.LATE THIS AFTERNOON...Northwest winds 10 to 20 knots. Waves 2 to
4 feet.
.TONIGHT...West winds 5 to 15 knots diminishing to less than
10 knots after midnight, then increasing to 5 to 15 knots late.
Waves subsiding to calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots. 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 10 to 20 knots. A chance of showers. A
slight chance of thunderstorms by mid afternoon. Waves building
to 2 to 4 feet, then subsiding to 1 to 3 feet.
.SUNDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm
to 2 feet.
.MONDAY...West winds 5 to 15 knots becoming southwest less than
10 knots by mid afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...South winds less than 10 knots becoming west 5 to
15 knots after midnight. Waves calm to 2 feet.
.TUESDAY...Northwest winds 5 to 15 knots. Waves building to 1 to
3 feet.
.WEDNESDAY...North winds 5 to 15 knots. Waves subsiding to calm
to 2 feet.

$$

LSZ265-190415-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
402 PM EDT Fri Aug 18 2017

.LATE THIS AFTERNOON...Northwest winds 10 to 20 knots. Waves 2 to
4 feet.
.TONIGHT...West winds 5 to 15 knots. Waves subsiding to calm to
2 feet.
.SATURDAY...West winds 5 to 15 knots backing southwest 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. A chance of showers and
a slight chance of thunderstorms by mid afternoon. Waves calm to
2 feet.
.SUNDAY NIGHT...Southwest winds 5 to 15 knots becoming west 10 to
20 knots after midnight. A chance of showers and thunderstorms.
Waves calm to 2 feet.
.MONDAY...West winds 5 to 15 knots veering northeast by mid
afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...East winds 5 to 15 knots backing northeast after
midnight. A chance of showers. Waves calm to 2 feet.
.TUESDAY...Northwest winds 10 to 20 knots. A chance of showers.
Waves building to 1 to 3 feet.
.WEDNESDAY...North winds 10 to 20 knots. Waves subsiding to calm
to 2 feet.

$$

LSZ266-190415-
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-
402 PM EDT Fri Aug 18 2017

.LATE THIS AFTERNOON...Northwest winds 15 to 25 knots. Waves 4 to
7 feet occasionally to 9 feet subsiding to 3 to 6 feet
occasionally to 8 feet.
.TONIGHT...Northwest winds 10 to 20 knots diminishing to 5 to
15 knots after midnight, then backing west late. Waves subsiding
to 1 to 3 feet.
.SATURDAY...West winds 5 to 15 knots backing southwest in the
afternoon. 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 subsiding to calm to 2 feet,
then building to 1 to 3 feet.
.SUNDAY...Southwest winds 10 to 20 knots backing south by mid
afternoon. A chance of showers and a slight chance of
thunderstorms by mid afternoon. Waves 1 to 3 feet.
.SUNDAY NIGHT...Southwest winds 5 to 15 knots veering west after
midnight. Waves subsiding to calm to 2 feet.
.MONDAY...West winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY NIGHT...East winds 5 to 15 knots backing northeast after
midnight. A chance of showers. Waves calm to 2 feet.
.TUESDAY...Northwest winds 10 to 20 knots. A chance of showers.
Waves building to 2 to 4 feet.
.WEDNESDAY...North winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves subsiding to 1 to 3 feet,
then building to 2 to 4 feet.

$$

LSZ267-190415-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
402 PM EDT Fri Aug 18 2017

.LATE THIS AFTERNOON...Northwest winds 20 to 30 knots. Isolated
showers. Waves 3 to 6 feet occasionally to 8 feet building to
4 to 7 feet occasionally to 9 feet.
.TONIGHT...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Isolated showers through midnight.
Patchy fog after midnight. Waves subsiding to 1 to 3 feet.
.SATURDAY...West winds 5 to 15 knots backing southwest 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...South winds 5 to 15 knots increasing to 10 to 20 knots
by mid afternoon. A slight chance of showers and thunderstorms by
mid afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...Southwest winds 10 to 20 knots diminishing to
5 to 15 knots after midnight. A chance of showers and
thunderstorms. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots veering west by mid
afternoon. A chance of showers. Waves calm to 2 feet.
.MONDAY NIGHT...East winds 5 to 15 knots backing north after
midnight. A chance of showers. Waves calm to 2 feet.
.TUESDAY...Northwest winds 10 to 20 knots. A chance of showers.
Waves building to 2 to 4 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots veering north. Waves
subsiding to 1 to 3 feet, then building to 2 to 4 feet.

$$

LSZ261-190415-
MAFOR 1821/
Superior West 11510 11610 11600 13610 12510. Waves 1 to 2 feet.

Superior North Central 11720 11610 12600 11500 13510. Waves 1 to
3 feet.

Superior South Central 11730 11710 14600 11600 11500. Waves 3 to
5 feet subsiding to 1 to 3 feet tonight and Saturday.

Superior East 12730 11720 12710 11600 12500. Waves 2 to 6 feet
subsiding to 1 to 3 feet Saturday.

$$

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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