Great Lakes Forecast
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FZUS63 KMQT 190759
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
359 AM EDT Thu Oct 19 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...A nearly stationary 30.2 inch area of high pressure
across the Mid Atlantic states will push a 30.0 inch ridge across
Lake Superior later today into Friday. A 29.1 inch low pressure
over the Canadian Prairies on Friday will track toward Hudson Bay
through Sunday, passing a 29.8 inch trough across Lake Superior by
Saturday night. Weak ridging of 29.9 inches will track eastward
across Lake Superior on Sunday ahead of a 29.7 inch trough
approaching from the west on Monday.

LSZ162-191600-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
359 AM EDT Thu Oct 19 2017 /259 AM CDT Thu Oct 19 2017/

.EARLY THIS MORNING...West winds 20 to 30 knots. Waves 5 to
8 feet occasionally to 10 feet.
.TODAY...West winds 20 to 30 knots becoming southwest 15 to 25
knots in the afternoon, then diminishing to 10 to 20 knots late.
Waves subsiding to 2 to 4 feet.
.TONIGHT...Southwest winds 10 to 20 knots. Waves subsiding to
calm to 2 feet, then building to 1 to 3 feet.
.FRIDAY...South winds 10 to 20 knots diminishing to 5 to 15 knots
in the afternoon. Waves subsiding to calm to 2 feet.
.FRIDAY NIGHT...South winds 10 to 20 knots. A slight chance of
showers after midnight. Waves building to 2 to 4 feet.
.SATURDAY...South winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. Showers likely by mid afternoon. Waves
subsiding to 1 to 3 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight. Showers likely through midnight, then a chance of
showers after midnight. Waves 1 to 3 feet.
.SUNDAY...West winds 10 to 20 knots backing southwest. A chance
of showers. Waves subsiding to calm to 2 feet, then building to
1 to 3 feet.
.MONDAY...Southwest winds 10 to 20 knots becoming northwest 15 to
25 knots. A chance of showers. Waves subsiding to calm to 2 feet,
then building to 3 to 5 feet occasionally to 7 feet.

$$

LSZ263-191600-
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-
359 AM EDT Thu Oct 19 2017

...GALE WARNING IN EFFECT UNTIL 2 PM EDT THIS AFTERNOON...

.EARLY THIS MORNING...West winds 20 to 30 knots. Waves 7 to
10 feet occasionally to 13 feet.
.TODAY...West gales to 35 knots becoming southwest 20 to 30 knots
late. Waves building to 8 to 11 feet occasionally to 14 feet,
then subsiding to 3 to 6 feet occasionally to 8 feet.
.TONIGHT...Southwest winds 10 to 20 knots. Waves subsiding to
1 to 3 feet, then building to 2 to 4 feet.
.FRIDAY...Southwest winds 5 to 15 knots backing south in the
afternoon. Waves subsiding to calm to 2 feet.
.FRIDAY NIGHT...South winds 10 to 20 knots. Waves building to
2 to 4 feet.
.SATURDAY...South winds 10 to 20 knots. A chance of showers.
Waves subsiding to 1 to 3 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight. Showers likely. Waves 1 to 3 feet.
.SUNDAY...West winds 10 to 20 knots backing southwest. Waves 1 to
3 feet.
.MONDAY...Southwest winds 10 to 20 knots becoming north 15 to
25 knots. A chance of showers. Waves subsiding to calm to 2 feet,
then building to 3 to 6 feet occasionally to 8 feet.

$$

LSZ264-191600-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
359 AM EDT Thu Oct 19 2017

...GALE WARNING IN EFFECT THROUGH THIS AFTERNOON...

.EARLY THIS MORNING...West gales to 35 knots. Waves 7 to 11 feet
occasionally to 13 feet.
.TODAY...West gales to 35 knots. Waves building to 9 to 12 feet
occasionally to 15 feet, then subsiding to 5 to 8 feet
occasionally to 10 feet.
.TONIGHT...Southwest winds 10 to 20 knots. Waves subsiding to
1 to 3 feet, then building to 2 to 4 feet.
.FRIDAY...Southwest winds 5 to 15 knots backing south in the
afternoon. Waves subsiding to 1 to 3 feet.
.FRIDAY NIGHT...South winds 10 to 20 knots. Waves building to
2 to 4 feet.
.SATURDAY...South winds 10 to 20 knots. A chance of showers.
Waves building to 3 to 6 feet occasionally to 8 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots. A chance of showers
through midnight, then showers likely after midnight. Waves
subsiding to 3 to 5 feet occasionally to 7 feet.
.SUNDAY...Southwest winds 10 to 20 knots. Showers likely. Waves
subsiding to 1 to 3 feet.
.MONDAY...Southwest winds 10 to 20 knots becoming north 20 to
30 knots. A chance of showers. Waves building to 5 to 8 feet
occasionally to 10 feet.

$$

LSZ265-191600-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
359 AM EDT Thu Oct 19 2017

.EARLY THIS MORNING...West winds 20 to 30 knots. A few gale force
gusts to 35 knots. Waves 3 to 6 feet occasionally to 8 feet
building to 4 to 7 feet occasionally to 9 feet.
.TODAY...West winds 20 to 30 knots with a few gale force gusts to
35 knots diminishing to 15 to 25 knots. Waves building to 5 to 8
feet occasionally to 10 feet, then subsiding to 2 to 4 feet.
.TONIGHT...Southwest winds 10 to 20 knots. Waves subsiding to
calm to 2 feet.
.FRIDAY...South winds 10 to 20 knots. Waves building to 1 to
3 feet.
.FRIDAY NIGHT...South winds 15 to 25 knots. Waves building to
2 to 4 feet, then subsiding to 1 to 3 feet.
.SATURDAY...South winds 15 to 25 knots. A chance of showers.
Waves building to 3 to 5 feet occasionally to 7 feet, then
subsiding to 2 to 4 feet.
.SATURDAY NIGHT...South winds 15 to 25 knots. A chance of
showers. Waves subsiding to 2 to 4 feet.
.SUNDAY...Southwest winds 15 to 25 knots diminishing to 10 to
20 knots. Showers likely. Waves subsiding to calm to 2 feet.
.MONDAY...Southwest winds 10 to 20 knots becoming north 20 to
30 knots. A chance of showers. Waves building to 5 to 8 feet
occasionally to 10 feet.

$$

LSZ266-191600-
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-
359 AM EDT Thu Oct 19 2017

...GALE WARNING IN EFFECT THROUGH THIS AFTERNOON...

.EARLY THIS MORNING...West gales to 35 knots. Waves 7 to 10 feet
occasionally to 13 feet building to 9 to 12 feet occasionally to
15 feet.
.TODAY...West gales to 35 knots. Waves subsiding to 6 to 9 feet
occasionally to 11 feet.
.TONIGHT...Southwest winds 10 to 20 knots. Waves subsiding to
1 to 3 feet, then building to 2 to 4 feet.
.FRIDAY...South winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon, then increasing to 15 to 25 knots
late. Waves subsiding to 1 to 3 feet, then building to 2 to
4 feet.
.FRIDAY NIGHT...South winds 20 to 30 knots. Waves building to
3 to 5 feet occasionally to 7 feet.
.SATURDAY...South winds 15 to 25 knots. A chance of showers.
Waves building to 3 to 6 feet occasionally to 8 feet.
.SATURDAY NIGHT...South winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. A chance of showers through midnight,
then showers likely after midnight. Waves building to 4 to 7 feet
occasionally to 9 feet, then subsiding to 3 to 5 feet
occasionally to 7 feet.
.SUNDAY...Southwest winds 15 to 25 knots. Showers likely. Waves
subsiding to 1 to 3 feet.
.MONDAY...Southwest winds 15 to 25 knots becoming north 20 to
30 knots. A chance of showers. Waves building to 5 to 8 feet
occasionally to 10 feet.

$$

LSZ267-191600-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
359 AM EDT Thu Oct 19 2017

...GALE WARNING IN EFFECT THROUGH THIS AFTERNOON...

.EARLY THIS MORNING...West gales to 35 knots. Waves 6 to 9 feet
occasionally to 11 feet building to 7 to 10 feet occasionally to
13 feet.
.TODAY...West gales to 40 knots diminishing to 20 to 30 knots
late. Waves building to 9 to 12 feet occasionally to 15 feet,
then subsiding to 6 to 9 feet occasionally to 11 feet.
.TONIGHT...West winds 10 to 20 knots backing southwest after
midnight, then increasing to 15 to 25 knots late. Waves subsiding
to 1 to 3 feet, then building to 2 to 4 feet.
.FRIDAY...Southwest winds 15 to 25 knots becoming south 10 to
20 knots in the afternoon, then increasing to 15 to 25 knots
late. Waves subsiding to 1 to 3 feet.
.FRIDAY NIGHT...South winds 15 to 25 knots. Waves building to
2 to 4 feet.
.SATURDAY...South winds 15 to 25 knots. Waves building to 3 to
5 feet occasionally to 7 feet.
.SATURDAY NIGHT...South winds 15 to 25 knots. A chance of
showers. Waves subsiding to 2 to 4 feet.
.SUNDAY...Southwest winds 15 to 25 knots diminishing to 10 to
20 knots. Showers likely, then a chance of showers. Waves
subsiding to calm to 2 feet.
.MONDAY...South winds 15 to 25 knots backing north. A chance of
showers. Waves building to 4 to 7 feet occasionally to 9 feet.

$$

LSZ261-191600-
MAFOR 1909/

Superior West...13640 11530 14520. Waves 5 to 8 feet subsiding to
1 to 3 feet tonight.

Superior North Central...Gale Warning in effect...14650 11640
12520 11530. Waves 7 to 12 feet subsiding to 2 to 4 feet tonight.

Superior South Central...Gale Warning in effect...11640 12650
11640 11630 13510. Waves 5 to 8 feet subsiding to 1 to 3 feet
tonight.

Superior East...Gale Warning in effect...14650 11640 11620 11510
11520. Waves 6 to 10 feet building to 9 to 12 feet today. Waves subsiding
to 3 to 5 feet tonight.

$$

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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