Great Lakes Forecast
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FZUS63 KMQT 220258
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
958 PM EST Tue Nov 21 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 30.5 inch high over the Central Plains will extend
northeastward overnight and weaken to 30.2 inches as it passes
through the Ohio River Valley late Wednesday. Early Thursday
morning, a 29.9 inch trough in eastern Manitoba will quickly swing
south across the Upper Great Lakes only to be replaced by a 30.0
inch ridge late Thursday night. Friday morning, a 29.0 inch low
will track east across central and eastern Manitoba reaching
northern Ontario by Friday evening. A 30.2 inch ridge will then
move into the northern plains on Saturday, reaching the central
Mississippi River Valley by Sunday.

LSZ162-221100-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
958 PM EST Tue Nov 21 2017 /858 PM CST Tue Nov 21 2017/

.REST OF TONIGHT...Northwest winds 20 to 30 knots becoming west
10 to 20 knots late. Isolated snow showers. Waves 3 to 6 feet
occasionally to 8 feet subsiding to 1 to 3 feet.
.WEDNESDAY...West winds 10 to 20 knots becoming southwest 15 to
25 knots. Scattered snow showers in the afternoon. Waves building
to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots veering west by
midnight. A chance of snow showers. Waves 3 to 5 feet subsiding
to 2 to 4 feet.
.THURSDAY...Northwest winds 10 to 20 knots becoming west 5 to
15 knots in the afternoon. Waves subsiding to calm to 2 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots increasing to
10 to 20 knots after midnight. Waves building to 2 to 4 feet.
.FRIDAY...Southwest winds 15 to 25 knots. A chance of rain
showers in the morning, then rain showers likely in the
afternoon. Waves building to 3 to 5 feet occasionally to 7 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots increasing to gales to
35 knots after midnight. A chance of rain showers. A chance of
snow showers after midnight. Waves building to 5 to 8 feet
occasionally to 10 feet.
.SATURDAY...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots. A chance of snow showers. Waves subsiding to calm to
2 feet, then building to 1 to 3 feet.
.SUNDAY...West winds 10 to 20 knots backing southwest. Waves
subsiding to calm to 2 feet, then building to 2 to 4 feet.

$$

LSZ263-221100-
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-
958 PM EST Tue Nov 21 2017

.REST OF TONIGHT...Northwest winds 20 to 30 knots diminishing to
10 to 20 knots and backing west late. Isolated snow showers.
Waves 5 to 8 feet occasionally to 10 feet subsiding to 2 to 4
feet.
.WEDNESDAY...West winds 10 to 20 knots becoming southwest 15 to
25 knots by mid afternoon. Isolated snow showers. Waves building
to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots veering west by
midnight. A chance of snow showers. Waves building to 4 to 7 feet
occasionally to 9 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.THURSDAY...Northwest winds 10 to 20 knots becoming west 5 to
15 knots in the afternoon. Waves subsiding to calm to 2 feet.
.THURSDAY NIGHT...South winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Waves building to 2 to 4 feet.
.FRIDAY...Southwest winds 15 to 25 knots increasing to 20 to 30
knots. Rain showers likely in the afternoon. Waves building to 4
to 7 feet occasionally to 9 feet.
.FRIDAY NIGHT...West gales to 35 knots. A chance of rain showers.
A chance of snow showers after midnight. Waves building to 7 to
10 feet occasionally to 13 feet.
.SATURDAY...Northwest gales to 35 knots diminishing to 15 to
25 knots. A chance of snow showers. Waves subsiding to 1 to
3 feet.
.SUNDAY...West winds 10 to 20 knots backing southwest. Waves
subsiding to calm to 2 feet, then building to 2 to 4 feet.

$$

LSZ264-221100-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
958 PM EST Tue Nov 21 2017

.REST OF TONIGHT...Northwest winds 20 to 30 knots diminishing to
10 to 20 knots and backing west late. Isolated snow showers.
Waves 6 to 9 feet occasionally to 11 feet subsiding to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY...West winds 10 to 20 knots increasing to 15 to
25 knots and backing southwest by mid afternoon. Isolated snow
showers. Waves subsiding to 2 to 4 feet, then building to 3 to 5
feet occasionally to 7 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots veering west by
midnight. A chance of snow showers. Waves building to 4 to 8 feet
occasionally to 10 feet.
.THURSDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon. A slight chance of snow showers in the
morning. Waves subsiding to 1 to 3 feet.
.THURSDAY NIGHT...South winds 5 to 15 knots increasing to 15 to
25 knots after midnight. A chance of rain and snow showers. Waves
subsiding to calm to 2 feet, then building to 2 to 4 feet.
.FRIDAY...Southwest winds 15 to 25 knots. Rain showers likely in
the afternoon. Waves building to 4 to 7 feet occasionally to
9 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots increasing to gales to
35 knots after midnight. A chance of rain showers. A chance of
snow showers after midnight. Waves building to 9 to 12 feet
occasionally to 15 feet.
.SATURDAY...Northwest gales to 40 knots diminishing to 15 to
25 knots late. A chance of snow showers. Waves building to 10 to
14 feet occasionally to 18 feet, then subsiding to 2 to 4 feet.
.SUNDAY...West winds 10 to 20 knots backing southwest. A chance
of snow showers. Waves subsiding to calm to 2 feet, then building
to 2 to 4 feet.

$$

LSZ265-221100-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
958 PM EST Tue Nov 21 2017

.REST OF TONIGHT...Northwest winds 20 to 30 knots becoming west 15
to 25 knots late. Scattered snow showers. Waves 6 to 9 feet
occasionally to 11 feet subsiding to 3 to 5 feet occasionally to 7
feet.
.WEDNESDAY...West winds 15 to 25 knots backing southwest by mid
afternoon. Isolated snow showers. Waves subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots becoming west
20 to 30 knots by midnight. A slight chance of snow showers.
Waves building to 3 to 5 feet occasionally to 7 feet.
.THURSDAY...West winds 20 to 30 knots becoming northwest 10 to
20 knots in the afternoon. A slight chance of snow showers in the
morning. Waves subsiding to 1 to 3 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots becoming south
15 to 25 knots after midnight. Waves subsiding to calm to 2 feet,
then building to 1 to 3 feet.
.FRIDAY...Southwest winds 20 to 30 knots. A chance of rain
showers in the afternoon. Waves building to 2 to 4 feet, then
subsiding to 1 to 3 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots increasing to gales to
35 knots after midnight. A chance of rain and snow showers late.
Waves building to 7 to 10 feet occasionally to 13 feet.
.SATURDAY...Northwest gales to 35 knots diminishing to 20 to
30 knots. Snow showers. Waves building to 9 to 12 feet
occasionally to 15 feet, then subsiding to 2 to 4 feet.
.SUNDAY...West winds 15 to 25 knots backing southwest. A chance
of snow showers. Waves subsiding to calm to 2 feet, then building
to 1 to 3 feet.

$$

LSZ266-221100-
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-
958 PM EST Tue Nov 21 2017

.REST OF TONIGHT...Northwest winds 20 to 30 knots diminishing to
15 to 25 knots late. Scattered snow showers. Waves 9 to 12 feet
occasionally to 15 feet subsiding to 4 to 7 feet occasionally to 9
feet.
.WEDNESDAY...Northwest winds 15 to 25 knots backing southwest by
mid afternoon. Scattered snow showers. Waves subsiding to 2 to
4 feet, then building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots increasing to
20 to 30 knots by midnight, then veering west late. A chance of
snow showers. Waves building to 4 to 8 feet occasionally to
10 feet.
.THURSDAY...West winds 20 to 30 knots becoming northwest 15 to
25 knots in the afternoon. A chance of snow showers, possibly
mixed with rain in the morning. Waves building to 5 to 8 feet
occasionally to 10 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots becoming south
15 to 25 knots after midnight. A chance of rain and snow showers
late. Waves subsiding to 1 to 3 feet, then building to 2 to 4
feet.
.FRIDAY...South winds 20 to 30 knots. Rain showers likely in the
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...West winds 20 to 30 knots increasing to gales to
35 knots after midnight. Rain and snow showers likely. Waves
building to 10 to 14 feet occasionally to 18 feet.
.SATURDAY...Northwest gales to 40 knots diminishing to 20 to
30 knots. Snow showers likely. Waves building to 12 to 17 feet
occasionally to 21 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.SUNDAY...Northwest winds 15 to 25 knots backing southwest. Snow
showers likely. Waves subsiding to 1 to 3 feet.

$$

LSZ267-221100-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
958 PM EST Tue Nov 21 2017

.REST OF TONIGHT...Northwest winds 20 to 30 knots diminishing to
15 to 25 knots late. Numerous snow showers. Waves 8 to 11 feet
occasionally to 14 feet subsiding to 4 to 7 feet occasionally to 9
feet.
.WEDNESDAY...Northwest winds 15 to 25 knots backing southwest by mid
afternoon. Scattered snow showers. Waves subsiding to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY NIGHT...Southwest winds 15 to 25 knots increasing to
20 to 30 knots by midnight, then veering west late. A chance of
snow showers. Waves building to 3 to 6 feet occasionally to
8 feet.
.THURSDAY...West winds 20 to 30 knots veering northwest in the
afternoon. A chance of snow showers, possibly mixed with rain.
Waves building to 5 to 8 feet occasionally to 10 feet, then
subsiding to 3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...West winds 10 to 20 knots becoming south 15 to
25 knots after midnight. A chance of rain and snow showers late. Waves
subsiding to 1 to 3 feet, then building to 2 to 4 feet.
.FRIDAY...South gales to 35 knots veering southwest late. Rain
showers likely. Waves building to 4 to 7 feet occasionally to 9
feet.
.FRIDAY NIGHT...Southwest gales to 35 knots veering west after
midnight. Rain and snow showers. Waves building to 10 to 14 feet
occasionally to 18 feet.
.SATURDAY...Northwest gales to 40 knots diminishing to 20 to
30 knots. Snow showers likely. Waves building to 12 to 17 feet
occasionally to 21 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.SUNDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots. A chance of snow showers. Waves subsiding to 1 to
3 feet.

$$
LSZ261-221100-
MAFOR 2204/
Superior West 11740 11720 13620 13530. Chance of snow showers
Wednesday evening. Waves 3 to 7 feet.

Superior North Central 11740 11730 11720 12620 11630 12530.
Chance of snow showers Wednesday evening. Waves 4 to 8 feet.

Superior South Central 11740 11730 11720 11620 11630 11530 12520.
Scattered snow showers. Waves 6 to 9 feet subsiding to 4 to 7
feet overnight, and then subsiding to 1 to 3 feet Wednesday
evening.

Superior East 11740 11730 12720 12620 12530. Scattered snow
showers. Waves 6 to 10 feet subsiding to 5 to 8 feet overnight,
then subsiding to 3 to 5 feet Wednesday.

$$

Borchardt

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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