Great Lakes Forecast
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FZUS63 KMQT 231959
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
359 PM EDT Mon Oct 23 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 low pressure trough of 29.7 inches over eastern Lake
Superior this evening will exit across southern Ontario tonight. The
trough will then give way to low pressure of 29.4 inches organizing
over Saginaw Bay tonight. As this low lifts north to eastern Upper
Michigan on Tuesday morning, it will rapidly deepen to 28.9 inches.
The low will then meander across the northern Lake Huron shoreline
on Tuesday night as it weakens to 29.3 inches. As the low weakens
further on Wednesday while lifting toward southern Quebec, a 29.7
inch high pressure ridge will reach Lake Superior. Another low
pressure at 29.4 inches over the Northern Plains Wednesday evening
will track east, reaching the Upper Great Lakes on Thursday night.
This low will move across the Upper Great Lakes and weaken to 29.7
inches over southern Ontario on Friday night. A 30.1 inch ridge will
then shift over the Upper Great Lakes on Saturday.

LSZ162-240400-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
359 PM EDT Mon Oct 23 2017 /259 PM CDT Mon Oct 23 2017/

...GALE WARNING IN EFFECT FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT
THROUGH LATE TUESDAY NIGHT...

.LATE THIS AFTERNOON...West winds 10 to 20 knots. A slight chance
of showers. Waves 1 to 3 feet subsiding to calm to 2 feet.
.TONIGHT...Northwest winds 20 to 30 knots becoming north gales to
45 knots after midnight. A chance of showers. Waves building to
9 to 12 feet occasionally to 15 feet.
.TUESDAY...North gales to 45 knots. A chance of showers. Waves
building to 10 to 14 feet occasionally to 18 feet, then subsiding
to 7 to 10 feet occasionally to 13 feet.
.TUESDAY NIGHT...North gales to 35 knots becoming northwest 20 to
30 knots after midnight, then diminishing to 10 to 20 knots late.
A chance of rain showers after midnight. Waves subsiding to 2 to
4 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots becoming west 5 to
15 knots by mid afternoon. A slight chance of rain showers
through early afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...Southeast winds 5 to 15 knots increasing to
10 to 20 knots after midnight. A chance of showers after
midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 10 to 20 knots becoming north gales
to 35 knots by mid afternoon. Showers. Waves building to 3 to
6 feet occasionally to 8 feet.
.THURSDAY NIGHT...North gales to 45 knots. Rain showers. Snow
showers likely after midnight. Waves building to 10 to 14 feet
occasionally to 18 feet.
.FRIDAY...North gales to 40 knots becoming northwest 10 to
20 knots. A chance of rain showers, possibly mixed with snow.
Waves subsiding to calm to 2 feet.
.SATURDAY...Northwest winds 10 to 20 knots increasing to 15 to
25 knots. A chance of rain showers. Waves building to 2 to
4 feet.

$$

LSZ263-240400-
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 PM EDT Mon Oct 23 2017

...STORM WARNING IN EFFECT FROM 2 AM EDT TUESDAY THROUGH TUESDAY
EVENING...

.LATE THIS AFTERNOON...West winds 5 to 15 knots. Waves 1 to
3 feet subsiding to calm to 2 feet.
.TONIGHT...North winds 20 to 30 knots increasing to storm force
winds of 50 knots after midnight. A chance of showers. Waves
building to 10 to 14 feet occasionally to 18 feet.
.TUESDAY...North storm force winds to 60 knots. Rain showers.
Waves building to 15 to 20 feet occasionally to 25 feet, then
subsiding to 12 to 17 feet occasionally to 21 feet.
.TUESDAY NIGHT...North gales to 45 knots diminishing to 15 to 25
knots through the night. A chance of rain showers. Waves
subsiding to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...North winds 10 to 20 knots becoming northwest 5 to
15 knots by mid afternoon. A chance of rain showers through early
afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...Southeast winds 5 to 15 knots increasing to
10 to 20 knots after midnight. A chance of rain showers after
midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 15 to 25 knots becoming east 20 to
30 knots by mid afternoon. Rain showers. Waves building to 3 to
6 feet occasionally to 8 feet.
.THURSDAY NIGHT...North gales to 45 knots. Rain showers. Snow
showers likely after midnight. Waves building to 11 to 15 feet
occasionally to 19 feet.
.FRIDAY...North gales to 45 knots becoming northwest 15 to
25 knots. A chance of rain showers, possibly mixed with snow.
Waves subsiding to 1 to 3 feet.
.SATURDAY...Northwest winds 5 to 15 knots increasing to 15 to
25 knots. A chance of rain showers. Waves subsiding to calm to
2 feet, then building to 2 to 4 feet.

$$

LSZ264-240400-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
359 PM EDT Mon Oct 23 2017

...STORM WARNING IN EFFECT FROM LATE TONIGHT THROUGH TUESDAY
EVENING...

.LATE THIS AFTERNOON...Southeast winds 5 to 15 knots. Waves 1 to
3 feet.
.TONIGHT...Northeast winds 5 to 15 knots becoming north 20 to
30 knots after midnight, then increasing to gales to 45 knots
late. showers. Waves building to 10 to 14 feet occasionally to 18
feet.
.TUESDAY...North storm force winds to 60 knots with a few hurricane
force wind gusts to 65 knots. Rain showers. Waves building to 20
to 25 feet occasionally to 31 feet, then subsiding to 15 to 20
feet occasionally to 25 feet.
.TUESDAY NIGHT...North storm force winds to 50 knots diminishing
to 20 to 30 knots. Rain showers likely through midnight, then a
slight chance of rain showers after midnight. Waves subsiding to
5 to 8 feet occasionally to 10 feet.
.WEDNESDAY...North winds 15 to 25 knots diminishing to 5 to
15 knots by mid afternoon. A slight chance of rain showers
through early afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots becoming southeast
10 to 20 knots after midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 15 to 25 knots. Showers. Waves
building to 3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...Northeast gales to 45 knots becoming north
storm force winds to 50 knots after midnight. Rain showers. Waves
building to 12 to 17 feet occasionally to 21 feet.
.FRIDAY...North storm force winds to 50 knots becoming northwest
20 to 30 knots. Rain showers likely, then a chance of rain
showers. Waves subsiding to 1 to 3 feet.
.SATURDAY...Northwest winds 10 to 20 knots increasing to 20 to
30 knots. A chance of snow showers. A chance of rain showers.
Waves subsiding to calm to 2 feet, then building to 3 to 6 feet
occasionally to 8 feet.

$$

LSZ265-240400-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
359 PM EDT Mon Oct 23 2017

...STORM WARNING IN EFFECT FROM LATE TONIGHT THROUGH TUESDAY
EVENING...

.LATE THIS AFTERNOON...Southeast winds 5 to 15 knots. Waves 1 to
3 feet.
.TONIGHT...Southeast winds 5 to 15 knots becoming north 20 to
30 knots after midnight, then increasing to storm force winds to
55 knots late. A slight chance of showers through midnight, then
showers after midnight. Waves subsiding to calm to 2 feet, then
building to 11 to 15 feet occasionally to 19 feet.
.TUESDAY...North storm force winds to 60 knots with a few
hurricane force wind gusts to 65 knots. Showers. Waves building
to 22 to 27 feet occasionally to 34 feet, then subsiding to 17 to
22 feet occasionally to 28 feet.
.TUESDAY NIGHT...North storm force winds to 55 knots diminishing
to gales to 40 knots after midnight, then becoming northwest
gales to 35 knots late. Rain showers through midnight, then a
chance of rain showers after midnight. Waves subsiding to 7 to
10 feet occasionally to 13 feet.
.WEDNESDAY...North winds 15 to 25 knots becoming northwest 10 to
20 knots by mid afternoon. A slight chance of rain showers
through early afternoon. Waves subsiding to 1 to 3 feet.
.WEDNESDAY NIGHT...North winds 5 to 15 knots becoming south 10 to
20 knots after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...South winds 15 to 25 knots backing southeast by mid
afternoon. A chance of rain showers through early afternoon, then
rain showers likely by mid afternoon. Waves building to 2 to
4 feet.
.THURSDAY NIGHT...East gales to 40 knots becoming northeast storm
force winds to 50 knots after midnight. Rain showers. Waves
building to 12 to 17 feet occasionally to 21 feet.
.FRIDAY...North gales to 45 knots becoming northwest gales to
35 knots. Rain showers likely, then a chance of rain showers,
possibly mixed with snow. Waves subsiding to 2 to 4 feet.
.SATURDAY...West winds 10 to 20 knots becoming northwest 15 to
25 knots. A chance of rain showers, possibly mixed with snow,
then rain showers likely. Waves subsiding to calm to 2 feet, then
building to 3 to 5 feet occasionally to 7 feet.

$$

LSZ266-240400-
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 PM EDT Mon Oct 23 2017

...STORM WARNING IN EFFECT FROM 2 AM EDT TUESDAY THROUGH TUESDAY
EVENING...

.LATE THIS AFTERNOON...Southeast winds 5 to 15 knots. Waves 1 to
3 feet.
.TONIGHT...East winds 10 to 20 knots becoming north gales to
45 knots after midnight, then increasing to storm force winds to
60 knots late. A chance of showers through midnight, then showers
after midnight. Waves subsiding to calm to 2 feet, then building
to 15 to 20 feet occasionally to 25 feet.
.TUESDAY...North storm force winds to 60 knots with a few
hurricane force wind gusts to 65 knots. Showers. Waves building
to 22 to 27 feet occasionally to 34 feet, then subsiding to 20 to
25 feet occasionally to 31 feet.
.TUESDAY NIGHT...North storm force winds to 55 knots diminishing
to gales to 45 knots after midnight. Rain showers. Waves
subsiding to 9 to 12 feet occasionally to 15 feet.
.WEDNESDAY...North winds 20 to 30 knots diminishing to 10 to
20 knots by mid afternoon. A slight chance of rain showers
through early afternoon. Waves subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...North winds 5 to 15 knots veering south after
midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...Southeast winds 15 to 25 knots. A chance of rain
showers through early afternoon, then rain showers likely by mid
afternoon. Waves building to 3 to 5 feet occasionally to 7 feet.
.THURSDAY NIGHT...East gales to 45 knots becoming northeast storm
force winds to 50 knots after midnight. Rain showers. Waves
building to 12 to 17 feet occasionally to 21 feet.
.FRIDAY...North storm force winds to 50 knots diminishing to
gales to 35 knots. Rain showers likely, then a chance of rain
showers. Waves subsiding to 3 to 5 feet occasionally to 7 feet.
.SATURDAY...West winds 10 to 20 knots increasing to 20 to
30 knots. A chance of rain showers, possibly mixed with snow,
then rain showers likely. Waves subsiding to 1 to 3 feet, then
building to 3 to 6 feet occasionally to 8 feet.

$$

LSZ267-240400-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
359 PM EDT Mon Oct 23 2017

...STORM WARNING IN EFFECT FROM 2 AM EDT TUESDAY THROUGH TUESDAY
AFTERNOON...

.LATE THIS AFTERNOON...East winds 5 to 15 knots. A slight chance
of showers. Waves calm to 2 feet.
.TONIGHT...Northeast winds 15 to 25 knots becoming north gales to
45 knots after midnight, then increasing to storm force winds to
55 knots late. Showers. Waves building to 12 to 17 feet
occasionally to 21 feet.
.TUESDAY...Northeast storm force winds to 55 knots diminishing to
gales to 45 knots in the afternoon. Showers. Waves building to
15 to 20 feet occasionally to 25 feet, then subsiding to 12 to
17 feet occasionally to 21 feet.
.TUESDAY NIGHT...North gales to 40 knots. Rain showers. Waves
subsiding to 8 to 11 feet occasionally to 14 feet.
.WEDNESDAY...North winds 20 to 30 knots becoming northwest 15 to
25 knots by mid afternoon. A chance of rain showers. Waves
subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...North winds 5 to 15 knots veering south after
midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...Southeast winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. A chance of rain showers. Waves
building to 2 to 4 feet.
.THURSDAY NIGHT...Southeast winds 20 to 30 knots backing east
after midnight. Showers. Waves building to 5 to 8 feet
occasionally to 10 feet.
.FRIDAY...North gales to 35 knots. Rain showers likely, then a
chance of rain showers. Waves subsiding to 4 to 7 feet
occasionally to 9 feet, then building to 6 to 9 feet occasionally
to 11 feet.
.SATURDAY...West winds 10 to 20 knots increasing to 15 to
25 knots. A chance of rain showers, then rain showers likely.
Waves subsiding to calm to 2 feet, then building to 3 to 5 feet
occasionally to 7 feet.

$$

LSZ261-240400-
MAFOR 2321/
Superior West...Storm Warning in effect...11610 11740 12850 11866
11876 11870 11860. showers through Tuesday. Waves 1 to 2 feet
building to 7 to 10 feet tonight. Waves 9 to 13 feet Tuesday.

Superior North Central...Storm Warning in effect...11310 11200
11120 11850 11876 13896. Chance of showers after midnight
tonight. Waves 1 to 3 feet building to 5 to 8 feet tonight. Waves
building to 16 to 21 feet Tuesday.

Superior South Central...Storm Warning in effect...11310 11200
11130 11856 11876 13896. Chance of showers after midnight
tonight. Waves 1 to 3 feet building to 7 to 10 feet tonight.
Waves building to 21 to 26 feet Tuesday.

Superior East...Storm Warning in effect...11310 11120 11156 13876
12176. Chance of showers late this evening tonight. Waves 1 to 2
feet building to 10 to 13 feet tonight. Waves building to 15 to
20 feet Tuesday.

$$

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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