Great Lakes Forecast
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FZUS63 KMQT 192009
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
409 PM EDT Mon Oct 19 2020

For waters beyond 5 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 ridge at 30.3 inches will remain over the region
through Tuesday afternoon as the high pressure system shifts east
to Quebec. Tuesday night, a low pressure system around 30.0 inches
will develop in the Midwest and track northeast across Lower
Michigan. This low will move quickly, reaching Quebec Wednesday
afternoon. Another low of 29.6 inches will develop over the
Central Plains Thursday and is expected to reach the Upper Great
Lakes Thursday night and weaken to 29.7 inches on Friday. A 30.3
inch ridge shifts over the Upper Great Lakes Saturday.

LSZ162-200415-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
409 PM EDT Mon Oct 19 2020 /309 PM CDT Mon Oct 19 2020/

.LATE THIS AFTERNOON...West winds 10 to 20 knots. Waves calm to
2 feet.
.TONIGHT...West winds 5 to 15 knots veering northwest after
midnight, then backing west late. A slight chance of rain showers
through midnight. Waves calm to 2 feet.
.TUESDAY...South winds 5 to 15 knots becoming southeast 10 to
20 knots in the afternoon. A slight chance of rain showers
through early afternoon, then rain showers, possibly mixed with
snow by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...Southeast winds 10 to 20 knots veering southwest
late. Snow, possibly mixed with rain through midnight, then a
chance of rain and snow after midnight. Waves building to 1 to
3 feet.
.WEDNESDAY...West winds 15 to 25 knots. Waves subsiding to calm
to 2 feet, then building to 2 to 4 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots backing east after
midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...East winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. Rain, possibly mixed with snow. Waves
building to 3 to 5 feet occasionally to 7 feet.
.THURSDAY NIGHT...Northeast winds 20 to 30 knots backing north
after midnight. Rain, possibly mixed with snow. Waves 3 to 6 feet
occasionally to 8 feet.
.FRIDAY...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots. A chance of rain and snow. Waves subsiding to calm to
2 feet.
.SATURDAY...West winds 10 to 20 knots becoming north 5 to
15 knots. Waves calm to 2 feet.

$$

LSZ263-200415-
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-
409 PM EDT Mon Oct 19 2020

.LATE THIS AFTERNOON...West winds 10 to 20 knots. A slight chance
of rain showers. Waves 1 to 3 feet.
.TONIGHT...West winds 10 to 20 knots veering northwest after
midnight, then diminishing to 5 to 15 knots late. A slight chance
of rain showers through midnight. Waves subsiding to calm to
2 feet.
.TUESDAY...South winds 5 to 15 knots backing southeast in the
afternoon, then increasing to 10 to 20 knots late. Rain showers
by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...Southeast winds 15 to 25 knots veering south
late. Rain, possibly mixed with snow. Waves building to 2 to
4 feet.
.WEDNESDAY...West winds 15 to 25 knots. A slight chance of rain
through early afternoon. Waves subsiding to 1 to 3 feet, then
building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...East winds 10 to 20 knots increasing to 20 to
30 knots by mid afternoon. A chance of rain, possibly mixed with
snow through early afternoon, then rain by mid afternoon. Waves
building to 3 to 5 feet occasionally to 7 feet.
.THURSDAY NIGHT...Northeast winds 20 to 30 knots becoming north
gales to 35 knots after midnight. Rain, possibly mixed with snow.
Waves 3 to 6 feet occasionally to 8 feet.
.FRIDAY...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots. A chance of rain, possibly mixed with snow. Waves
subsiding to 1 to 3 feet.
.SATURDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. Waves subsiding to calm to 2 feet.

$$

LSZ264-200415-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
409 PM EDT Mon Oct 19 2020

.LATE THIS AFTERNOON...West winds 5 to 15 knots. Waves 1 to
3 feet.
.TONIGHT...West winds 5 to 15 knots veering northwest after
midnight. Waves subsiding to calm to 2 feet.
.TUESDAY...Northwest winds less than 10 knots becoming southeast
5 to 15 knots in the afternoon. A chance of rain showers by mid
afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...Southeast winds 10 to 20 knots increasing to
15 to 25 knots after midnight, then becoming south 10 to 20 knots
late. Rain, possibly mixed with snow. Waves building to 3 to
5 feet occasionally to 7 feet.
.WEDNESDAY...West winds 15 to 25 knots. A chance of rain. Waves
subsiding to 2 to 4 feet, then building to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots becoming northwest
5 to 15 knots after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...East winds 5 to 15 knots increasing to 20 to 30 knots
by mid afternoon. A chance of rain through early afternoon, then
rain by mid afternoon. Waves building to 2 to 4 feet.
.THURSDAY NIGHT...East winds 20 to 30 knots backing north after
midnight. Rain. Snow likely after midnight. Waves building to
3 to 6 feet occasionally to 8 feet.
.FRIDAY...North winds 20 to 30 knots becoming northwest 10 to
20 knots. A chance of rain, possibly mixed with snow. Waves
subsiding to 2 to 4 feet.
.SATURDAY...Northwest winds 10 to 20 knots diminishing to 5 to
15 knots. Waves subsiding to calm to 2 feet.

$$

LSZ265-200415-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
409 PM EDT Mon Oct 19 2020

.LATE THIS AFTERNOON...West winds 5 to 15 knots. A slight chance
of rain showers. Waves calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots increasing to 10 to 20 knots
after midnight, then diminishing to 5 to 15 knots late. A slight
chance of rain showers through midnight. Waves calm to 2 feet.
.TUESDAY...Northwest winds 5 to 15 knots backing southeast in the
afternoon, then increasing to 10 to 20 knots late. Rain showers
by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...Southeast winds 15 to 25 knots becoming south
10 to 20 knots late. Rain, possibly mixed with snow. Waves
building to 3 to 5 feet occasionally to 7 feet, then subsiding to
2 to 4 feet.
.WEDNESDAY...West winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. A slight chance of rain through early
afternoon. Waves subsiding to 1 to 3 feet, then building to 2 to
4 feet.
.WEDNESDAY NIGHT...West winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...East winds 10 to 20 knots increasing to 20 to
30 knots by mid afternoon. A chance of rain through early
afternoon, then rain by mid afternoon. Waves building to 2 to
4 feet.
.THURSDAY NIGHT...East winds 20 to 30 knots becoming north 15 to
25 knots after midnight. Rain. Waves building to 3 to 5 feet
occasionally to 7 feet.
.FRIDAY...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots. A chance of rain. Waves 3 to 6 feet occasionally to 8
feet, then subsiding to 2 to 4 feet.
.SATURDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots. Waves subsiding to calm to 2 feet.

$$

LSZ266-200415-
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-
409 PM EDT Mon Oct 19 2020

.LATE THIS AFTERNOON...West winds 5 to 15 knots. A slight chance
of rain showers. Waves 1 to 3 feet subsiding to calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots increasing to 10 to 20 knots
after midnight, then becoming northwest 5 to 15 knots late. A
slight chance of rain showers. Waves building to 1 to 3 feet,
then subsiding to calm to 2 feet.
.TUESDAY...Northwest winds 5 to 15 knots backing southeast in the
afternoon, then increasing to 10 to 20 knots late. A chance of
rain showers by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...Southeast winds 15 to 25 knots diminishing to
10 to 20 knots late. Rain, possibly mixed with snow. Waves
building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...West winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. A chance of rain. Waves subsiding to
2 to 4 feet, then building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY NIGHT...West winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Waves subsiding to 1 to 3 feet.
.THURSDAY...East winds 10 to 20 knots increasing to 20 to
30 knots by mid afternoon. A chance of rain through early
afternoon, then rain by mid afternoon. Waves subsiding to calm to
2 feet, then building to 2 to 4 feet.
.THURSDAY NIGHT...East winds 20 to 30 knots becoming northeast
15 to 25 knots after midnight. Rain. Waves building to 3 to
5 feet occasionally to 7 feet.
.FRIDAY...Northwest winds 20 to 30 knots. A chance of rain. Waves
building to 4 to 7 feet occasionally to 9 feet, then subsiding to
3 to 5 feet occasionally to 7 feet.
.SATURDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. Waves subsiding to calm to 2 feet.

$$

LSZ267-200415-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
409 PM EDT Mon Oct 19 2020

.LATE THIS AFTERNOON...West winds 10 to 20 knots. A slight chance
of rain showers. Waves 1 to 3 feet subsiding to calm to 2 feet.
.TONIGHT...Northwest winds 10 to 20 knots diminishing to 5 to
15 knots late. A slight chance of rain showers. Waves calm to
2 feet.
.TUESDAY...Northwest winds 5 to 15 knots backing southeast in the
afternoon, then increasing to 10 to 20 knots late. Rain showers
likely by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...Southeast winds 15 to 25 knots. Rain. Snow after
midnight. Waves building to 2 to 4 feet.
.WEDNESDAY...West winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. A chance of rain. Waves subsiding to
1 to 3 feet, then building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY NIGHT...West winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Waves subsiding to 1 to 3 feet.
.THURSDAY...Southeast winds 10 to 20 knots increasing to 20 to
30 knots by mid afternoon. A chance of rain through early
afternoon, then rain by mid afternoon. Waves subsiding to calm to
2 feet, then building to 2 to 4 feet.
.THURSDAY NIGHT...East winds 20 to 30 knots becoming south 15 to
25 knots after midnight. Rain. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 2 to 4 feet.
.FRIDAY...Northwest winds 20 to 30 knots. Rain likely. Waves
building to 3 to 6 feet occasionally to 8 feet, then subsiding to
2 to 4 feet.
.SATURDAY...Northwest winds 10 to 20 knots. Waves subsiding to
calm to 2 feet.

$$

LSZ261-200415-
MAFOR 1921/
Superior West 12610 13700 12300 11310. A chance of rain showers
Tuesday afternoon. Waves 1 to 3 feet tonight. Waves 1 foot or
less Tuesday.

Superior North Central 12610 11710 12700 11600 11400 11310. Waves
1 to 3 feet tonight and Tuesday.

Superior South Central 11600 13610 12700 11200 11310. Waves 2
feet or less.

Superior East 11600 11700 13710 11700 11800 11300. Waves 1 to 3
feet.

$$

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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