Great Lakes Forecast
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577
FZUS63 KMQT 190203
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1003 PM EDT Mon Sep 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...High pressure of 30.1 inches will drift to southern
Quebec through Tuesday, then remain nearly stationary through
Thursday. A 29.5 inch trough developing over the northern High
Plains will weaken to 29.8 inches as it sweeps eastward, passing
across Lake Superior Wednesday afternoon and evening. Lake
Superior will then remain situated between a 30.1 inch ridge
across the Lower Great Lakes and a 29.8 inch trough over the Upper
Mississippi Valley Thursday through Saturday.

LSZ162-191015-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1003 PM EDT Mon Sep 18 2017 /903 PM CDT Mon Sep 18 2017/

.REST OF TONIGHT...South winds 5 to 15 knots backing southeast
after midnight. Waves calm to 2 feet.
.TUESDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots in the afternoon. Waves building to 1 to 3 feet.
.TUESDAY NIGHT...East winds 10 to 20 knots becoming southeast
15 to 25 knots after midnight. A slight chance of showers through
midnight, then showers likely and a slight chance of
thunderstorms after midnight. Waves 1 to 3 feet.
.WEDNESDAY...South winds 10 to 20 knots veering southwest by mid
afternoon. A chance of showers and thunderstorms. Waves building
to 2 to 4 feet, then subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots backing south after
midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...East winds 10 to 20 knots becoming south 5 to
15 knots after midnight. A chance of showers. Waves calm to
2 feet.
.FRIDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots. A chance of showers and thunderstorms. Waves building
to 1 to 3 feet.
.SATURDAY...South winds 10 to 20 knots becoming southwest 5 to
15 knots. A chance of showers, then showers likely. Waves
subsiding to calm to 2 feet.

$$

LSZ263-191015-
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-
1003 PM EDT Mon Sep 18 2017

.REST OF TONIGHT...South winds 5 to 15 knots backing southeast
after midnight. Isolated showers by late evening. Waves calm to
2 feet.
.TUESDAY...Southeast winds 5 to 15 knots backing east in the
afternoon. Waves building to 1 to 3 feet.
.TUESDAY NIGHT...East winds 10 to 20 knots veering southeast
after midnight. A chance of showers and a slight chance of
thunderstorms after midnight. Waves building to 2 to 4 feet.
.WEDNESDAY...Southeast winds 15 to 25 knots veering southwest by
mid afternoon. A chance of showers and thunderstorms. Waves
building to 3 to 5 feet occasionally to 7 feet, then subsiding to
2 to 4 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots becoming south less
than 10 knots after midnight. A slight chance of showers through
midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...Southeast winds 5 to 15 knots backing east by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 5 to 15 knots veering south
after midnight. A chance of showers. Waves calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots veering southeast. A chance of
showers. Waves building to 1 to 3 feet.
.SATURDAY...South winds 5 to 15 knots. A chance of showers. Waves
subsiding to calm to 2 feet.

$$

LSZ264-191015-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1003 PM EDT Mon Sep 18 2017

.REST OF TONIGHT...Southeast winds 5 to 15 knots. Isolated
showers by late evening. Waves 1 to 3 feet subsiding to calm to
2 feet.
.TUESDAY...Southeast winds 5 to 15 knots backing east late. Waves
building to 1 to 3 feet.
.TUESDAY NIGHT...Southeast winds 10 to 20 knots. A slight chance
of showers after midnight. Waves building to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY...Southeast winds 20 to 30 knots veering south by mid
afternoon. A chance of showers and thunderstorms through early
afternoon, then showers and thunderstorms likely by mid
afternoon. Waves building to 4 to 8 feet occasionally to 10 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots veering northwest
after midnight. A chance of showers and thunderstorms through
midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...Southeast winds less than 10 knots increasing to 5 to
15 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 5 to 15 knots veering south
after midnight. A chance of showers. Waves calm to 2 feet.
.FRIDAY...Southeast winds 5 to 15 knots. A chance of showers.
Waves building to 1 to 3 feet, then subsiding to calm to 2 feet.
.SATURDAY...South winds 5 to 15 knots veering southwest. A chance
of showers. Waves subsiding to calm to 2 feet, then building to
1 to 3 feet.

$$

LSZ265-191015-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1003 PM EDT Mon Sep 18 2017

.REST OF TONIGHT...Southeast winds 10 to 20 knots. Scattered
showers. Waves 1 to 3 feet subsiding to calm to 2 feet.
.TUESDAY...Southeast winds 10 to 20 knots backing east late.
Waves building to 1 to 3 feet.
.TUESDAY NIGHT...Southeast winds 10 to 20 knots increasing to
15 to 25 knots after midnight. Waves building to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY...Southeast winds 20 to 30 knots becoming south 15 to
25 knots by mid afternoon. A chance of showers and thunderstorms.
Waves building to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots becoming northwest
5 to 15 knots after midnight. A chance of thunderstorms through
midnight. A chance of showers. Waves subsiding to calm to 2 feet.
.THURSDAY...Northeast winds 5 to 15 knots becoming east 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 10 to 20 knots veering south
after midnight. A chance of showers. Waves calm to 2 feet.
.FRIDAY...South winds 10 to 20 knots. A chance of showers. Waves
building to 1 to 3 feet.
.SATURDAY...South winds 10 to 20 knots. Waves subsiding to calm
to 2 feet.

$$

LSZ266-191015-
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-
1003 PM EDT Mon Sep 18 2017

.REST OF TONIGHT...Southeast winds 10 to 20 knots. Scattered
showers. Waves 1 to 3 feet subsiding to calm to 2 feet.
.TUESDAY...Southeast winds 10 to 20 knots backing east late.
Waves building to 1 to 3 feet.
.TUESDAY NIGHT...Southeast winds 10 to 20 knots increasing to
15 to 25 knots after midnight. Waves building to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY...Southeast winds 20 to 30 knots veering south by mid
afternoon. A chance of showers. A chance of thunderstorms by mid
afternoon. Waves building to 4 to 8 feet occasionally to 10 feet.
.WEDNESDAY NIGHT...South winds 10 to 20 knots becoming northwest
5 to 15 knots after midnight. Showers and thunderstorms likely
through midnight, then a slight chance of showers and
thunderstorms after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...North winds 5 to 15 knots veering east by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 10 to 20 knots becoming south
15 to 25 knots after midnight. A chance of showers. Waves calm to
2 feet.
.FRIDAY...South winds 10 to 20 knots. A chance of showers. Waves
building to 2 to 4 feet.
.SATURDAY...South winds 10 to 20 knots. Waves subsiding to 1 to
3 feet, then building to 2 to 4 feet.

$$

LSZ267-191015-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1003 PM EDT Mon Sep 18 2017

.REST OF TONIGHT...East winds 5 to 15 knots increasing to 10 to
20 knots late. Scattered showers. Waves calm to 2 feet.
.TUESDAY...Southeast winds 10 to 20 knots backing east in the
afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...Southeast winds 10 to 20 knots increasing to
15 to 25 knots late. Waves building to 2 to 4 feet.
.WEDNESDAY...Southeast winds 15 to 25 knots. A slight chance of
showers by mid afternoon. Waves building to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY NIGHT...South winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. A chance of showers and thunderstorms.
Waves subsiding to calm to 2 feet.
.THURSDAY...North winds 5 to 15 knots veering northeast by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 10 to 20 knots veering south
after midnight. A chance of showers. Waves calm to 2 feet.
.FRIDAY...South winds 10 to 20 knots. A chance of showers. Waves
calm to 2 feet.
.SATURDAY...South winds 10 to 20 knots. Waves building to 1 to
3 feet.

$$

LSZ261-191015-
MAFOR 1903/
Superior West 11410 11300 13310 11210 12220. Waves 1 to 3 feet.

Superior North Central 15310 12320. Waves 1 to 4 feet.


Superior South Central 14310 11310 11210 11220 11320. Scattered
showers after midnight overnight. Waves 1 to 3 feet.

Superior East 11210 11200 11210 12310 13210. Scattered showers
overnight. Waves 2 feet or less overnight and Tuesday. Waves 1 to
3 feet Tuesday evening.

$$

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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