Great Lakes Forecast
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000
FZUS63 KMQT 210137
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
937 PM EDT Wed Sep 20 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 cold front extending from central Lake Superior to
eastern Iowa will move through the Upper Great Lakes overnight.
Behind the front, high pressure of 30.0 inches will cross the
Upper Mississippi Valley overnight and linger across the Upper
Great Lakes through Thursday. Lake Superior will then remain
situated between a 30.1 inch ridge across the Lower Great Lakes
and a 29.7 inch trough over the Upper Mississippi Valley Friday
through Sunday. On Monday the trough axis shifts eastward over the
Upper Great Lakes.

LSZ162-210945-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
937 PM EDT Wed Sep 20 2017 /837 PM CDT Wed Sep 20 2017/

.REST OF TONIGHT...West winds 5 to 15 knots becoming southwest
less than 10 knots late. Waves 1 to 3 feet subsiding to calm to
2 feet.
.THURSDAY...East winds 5 to 15 knots increasing to 10 to 20 knots
late. Isolated showers by mid afternoon. Waves building to 2 to
4 feet.
.THURSDAY NIGHT...East winds 10 to 20 knots. A chance of showers
and thunderstorms. Waves subsiding to calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots becoming southeast 10 to
20 knots by mid afternoon. A chance of showers and thunderstorms.
Waves calm to 2 feet.
.FRIDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight. Waves building to 1 to 3 feet.
.SATURDAY...Southwest winds 10 to 20 knots becoming west 5 to
15 knots by mid afternoon. A chance of showers and thunderstorms.
Waves subsiding to calm to 2 feet.
.SATURDAY NIGHT...North winds 5 to 15 knots veering south after
midnight. A chance of showers and thunderstorms. Waves calm to
2 feet.
.SUNDAY...Southwest winds 10 to 20 knots backing northeast. A
chance of showers and thunderstorms. Waves calm to 2 feet.
.MONDAY...Northeast winds 10 to 20 knots veering east. A chance
of showers and thunderstorms. Waves building to 1 to 3 feet.

$$

LSZ263-210945-
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-
937 PM EDT Wed Sep 20 2017

.REST OF TONIGHT...West winds 5 to 15 knots becoming north less
than 10 knots late. Patchy fog. Waves 2 to 4 feet subsiding to
calm to 2 feet.
.THURSDAY...East winds less than 10 knots increasing to 10 to
20 knots. Waves building to 1 to 3 feet.
.THURSDAY NIGHT...East winds 10 to 20 knots becoming southeast
5 to 15 knots after midnight, then veering south late. A chance
of showers and thunderstorms. Waves subsiding to calm to 2 feet.
.FRIDAY...South winds 5 to 15 knots backing southeast by mid
afternoon. A chance of showers and thunderstorms. Waves calm to
2 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots veering southwest after
midnight. Waves building to 1 to 3 feet.
.SATURDAY...Southwest winds 5 to 15 knots. A chance of showers
and thunderstorms. Waves subsiding to calm to 2 feet.
.SATURDAY NIGHT...West winds 5 to 15 knots backing south after
midnight. A chance of showers and thunderstorms. Waves calm to
2 feet.
.SUNDAY...Southwest winds 5 to 15 knots backing south. A chance
of showers and thunderstorms. Waves calm to 2 feet.
.MONDAY...Northeast winds 5 to 15 knots veering east. A chance of
showers and thunderstorms. Waves building to 1 to 3 feet.

$$

LSZ264-210945-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
937 PM EDT Wed Sep 20 2017

.REST OF TONIGHT...West winds 5 to 15 knots veering northwest
after midnight, then becoming north less than 10 knots late.
Patchy fog. Waves 3 to 5 feet occasionally to 7 feet subsiding to
1 to 3 feet.
.THURSDAY...East winds less than 10 knots increasing to 5 to
15 knots in the afternoon. Patchy fog through early afternoon.
Waves subsiding to calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 5 to 15 knots. A chance of
showers. A chance of thunderstorms after midnight. Waves calm to
2 feet.
.FRIDAY...South winds 5 to 15 knots. A chance of showers and
thunderstorms. Waves building to 1 to 3 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots. A chance of showers
and thunderstorms. Waves 1 to 3 feet.
.SATURDAY...Southwest winds 5 to 15 knots. A chance of showers
and thunderstorms. Waves subsiding to calm to 2 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots backing south
after midnight. A chance of showers and thunderstorms. Waves calm
to 2 feet.
.SUNDAY...South winds 5 to 15 knots. A chance of showers and
thunderstorms. Waves calm to 2 feet.
.MONDAY...North winds 5 to 15 knots veering northeast. A chance
of showers and thunderstorms. Waves building to 1 to 3 feet.

$$

LSZ265-210945-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
937 PM EDT Wed Sep 20 2017

.REST OF TONIGHT...West winds 10 to 20 knots becoming northwest
5 to 15 knots after midnight, then veering north late. Patchy
fog. Waves 1 to 3 feet subsiding to calm to 2 feet.
.THURSDAY...North winds 5 to 15 knots veering east in the
afternoon. Patchy fog through early afternoon. Waves calm to
2 feet.
.THURSDAY NIGHT...Southeast winds 10 to 20 knots veering south
late. A chance of showers and thunderstorms after midnight. Waves
calm to 2 feet.
.FRIDAY...South winds 10 to 20 knots. A slight chance of showers
and thunderstorms through early afternoon. Waves building to 1 to
3 feet.
.FRIDAY NIGHT...South winds 10 to 20 knots. A chance of showers
and thunderstorms after midnight. Waves 1 to 3 feet.
.SATURDAY...South winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots. Waves calm to
2 feet.
.SUNDAY...Southwest winds 10 to 20 knots. Waves calm to 2 feet.
.MONDAY...East winds 10 to 20 knots. A chance of showers and
thunderstorms. Waves calm to 2 feet.

$$

LSZ266-210945-
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-
937 PM EDT Wed Sep 20 2017

.REST OF TONIGHT...West winds 10 to 20 knots veering northwest
after midnight, then becoming north 5 to 15 knots late. A chance
of showers and thunderstorms. Patchy fog. Waves 3 to 5 feet
occasionally to 7 feet subsiding to 1 to 3 feet.
.THURSDAY...North winds 5 to 15 knots veering east late. Patchy
fog through early afternoon. Waves subsiding to calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 10 to 20 knots veering south
late. A chance of showers and thunderstorms after midnight. Waves
calm to 2 feet.
.FRIDAY...South winds 10 to 20 knots. A chance of showers and
thunderstorms. Waves building to 1 to 3 feet.
.FRIDAY NIGHT...South winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. A chance of showers and thunderstorms.
Waves building to 2 to 4 feet.
.SATURDAY...South winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots. Waves calm to
2 feet.
.SUNDAY...South winds 10 to 20 knots. Waves building to 1 to
3 feet, then subsiding to calm to 2 feet.
.MONDAY...South winds 10 to 20 knots backing east. A chance of
showers and thunderstorms. Waves building to 1 to 3 feet.

$$

LSZ267-210945-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
937 PM EDT Wed Sep 20 2017

.REST OF TONIGHT...South winds 10 to 20 knots becoming northwest
5 to 15 knots late. Patchy fog. Showers likely, with a chance of
thunderstorms. Isolated showers late. Waves 3 to 5 feet
occasionally to 7 feet subsiding to calm to 2 feet.
.THURSDAY...North winds 5 to 15 knots becoming northeast less
than 10 knots in the afternoon, then veering east late. Patchy
fog through early afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...East winds 10 to 20 knots veering south late. A
chance of showers and thunderstorms after midnight. Waves calm to
2 feet.
.FRIDAY...South winds 10 to 20 knots. A chance of showers and
thunderstorms. Waves building to 1 to 3 feet.
.FRIDAY NIGHT...South winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. A chance of showers and thunderstorms.
Waves 1 to 3 feet.
.SATURDAY...South winds 10 to 20 knots. Waves subsiding to calm
to 2 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight. Waves calm to 2 feet.
.SUNDAY...South winds 10 to 20 knots. Waves calm to 2 feet.
.MONDAY...South winds 5 to 15 knots becoming southeast 10 to
20 knots. Waves calm to 2 feet.

$$
LSZ261-210945-
MAFOR 2103/
Superior West 11610 11600 11400 12200 11210 12220. Chance of
showers Thursday evening. Waves 1 to 4 feet.

Superior North Central 11710 11700 11800 11100 12200 11210 11310.
Patchy fog overnight and Thursday morning. Waves 1 to 4 feet.

Superior South Central 11610 11710 12800 11100 11200 11210 11310.
Patchy fog overnight and Thursday morning. Waves 2 feet or less.

Superior East 11526 11710 12810 12100 12200. Patchy fog. Chance
of showers and thunderstorms overnight. Patchy fog Thursday
morning. Waves 3 to 5 feet subsiding to 1 to 3 feet overnight.
Waves 1 to 2 feet Thursday and Thursday evening.

$$

RJT

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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