Great Lakes Forecast
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FZUS63 KMQT 230808
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
408 AM EDT Sun Jul 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...Low pressure of 29.7 inches over northern Lake
Michigan this morning will track to the lower Great Lakes through
tonight as high pressure of 30.0 inches over the northern Plains
builds toward the Upper Great Lakes. Expect the high to build
over the Upper Great Lakes on Monday. Trailing this surface high
will be a trough at 29.8 inches that will push across the Upper
Great Lakes on Tuesday night. A 30.0 inch ridge builds in behind
the surface trough Wednesday night and drops down into the Upper
Mississippi Valley by Friday.

LSZ162-231615-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
408 AM EDT Sun Jul 23 2017 /308 AM CDT Sun Jul 23 2017/

.EARLY THIS MORNING...North winds 5 to 15 knots. Patchy fog.
Isolated showers. Waves 1 to 3 feet.
.TODAY...North winds 5 to 15 knots increasing to 10 to 20 knots
in the afternoon, then veering northeast late. Isolated showers
through early afternoon. Waves building to 2 to 4 feet, then
subsiding to 1 to 3 feet.
.TONIGHT...Northeast winds 5 to 15 knots backing north late.
Waves subsiding to calm to 2 feet.
.MONDAY...West winds 5 to 15 knots backing southwest in the
afternoon, then backing east late. Waves calm to 2 feet.
.MONDAY NIGHT...East winds 5 to 15 knots veering south after
midnight. Waves calm to 2 feet.
.TUESDAY...South winds 10 to 20 knots. A chance of showers. A
chance of thunderstorms by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight. A chance of showers. Waves building to 1 to
3 feet.
.WEDNESDAY...West winds 10 to 20 knots becoming northwest 5 to
15 knots. Waves subsiding to calm to 2 feet.
.THURSDAY...West winds 5 to 15 knots veering northwest. Waves
calm to 2 feet.

$$

LSZ263-231615-
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-
408 AM EDT Sun Jul 23 2017

.EARLY THIS MORNING...Northwest winds 5 to 15 knots. Patchy fog.
Scattered showers. Waves calm to 2 feet building to 1 to 3 feet.
.TODAY...North winds 10 to 20 knots diminishing to 5 to 15 knots
in the afternoon, then veering northeast late. Scattered showers.
Waves 1 to 3 feet.
.TONIGHT...Northeast winds 5 to 15 knots becoming north less than
10 knots late. Waves subsiding to calm to 2 feet.
.MONDAY...West winds less than 10 knots becoming southwest 5 to
15 knots in the afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...East winds 5 to 15 knots veering south after
midnight. Waves calm to 2 feet.
.TUESDAY...South winds 5 to 15 knots. A chance of showers. Waves
calm to 2 feet.
.TUESDAY NIGHT...South winds 5 to 15 knots veering southwest
after midnight. A chance of showers and thunderstorms. Waves
building to 2 to 4 feet, then subsiding to 1 to 3 feet.
.WEDNESDAY...West winds 5 to 15 knots veering northwest. Waves
subsiding to calm to 2 feet.
.THURSDAY...West winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ264-231615-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
408 AM EDT Sun Jul 23 2017

.EARLY THIS MORNING...East winds 5 to 15 knots. Patchy fog.
Scattered showers. Waves 1 to 3 feet.
.TODAY...Northeast winds 10 to 20 knots diminishing to 5 to
15 knots late. Scattered showers. Waves subsiding to calm to 2
feet.
.TONIGHT...North winds 5 to 15 knots backing northwest after
midnight. Waves calm to 2 feet.
.MONDAY...West winds less than 10 knots backing southwest late.
Waves calm to 2 feet.
.MONDAY NIGHT...South winds 5 to 15 knots. Waves calm to 2 feet.
.TUESDAY...South winds 5 to 15 knots backing southeast by mid
afternoon. Waves building to 1 to 3 feet.
.TUESDAY NIGHT...South winds 5 to 15 knots veering southwest
after midnight. A chance of showers. A chance of thunderstorms
after midnight. Waves 1 to 3 feet.
.WEDNESDAY...West winds 5 to 15 knots veering northwest. Waves
subsiding to calm to 2 feet.
.THURSDAY...Northwest winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ265-231615-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
408 AM EDT Sun Jul 23 2017

.EARLY THIS MORNING...Northwest winds 10 to 20 knots. Patchy fog.
Scattered showers and isolated thunderstorms. Waves 1 to 3 feet.
.TODAY...Northwest winds 10 to 20 knots becoming north 15 to
25 knots in the afternoon, then veering northeast late. Isolated
thunderstorms through early afternoon. Scattered showers. Waves
building to 3 to 5 feet occasionally to 7 feet, then subsiding to
1 to 3 feet.
.TONIGHT...Northeast winds 10 to 20 knots backing north after
midnight. Isolated showers through midnight. Waves 1 to 3 feet.
.MONDAY...Northwest winds 5 to 15 knots veering north in the
afternoon, then veering east late. Waves subsiding to calm to 2
feet.
.MONDAY NIGHT...Southeast winds 5 to 15 knots becoming south
10 to 20 knots after midnight. Waves calm to 2 feet.
.TUESDAY...South winds 10 to 20 knots backing southeast by mid
afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...South winds 10 to 20 knots becoming southwest
15 to 25 knots after midnight. A chance of showers. A chance of
thunderstorms after midnight. Waves building to 1 to 3 feet.
.WEDNESDAY...West winds 10 to 20 knots veering northwest. A
chance of showers and thunderstorms. Waves subsiding to calm to
2 feet.
.THURSDAY...Northwest winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ266-231615-
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-
408 AM EDT Sun Jul 23 2017

.EARLY THIS MORNING...East winds 10 to 20 knots. Patchy fog.
Scattered showers and isolated thunderstorms. Waves 2 to 4 feet.
.TODAY...East winds 10 to 20 knots increasing to 15 to 25 knots
in the afternoon, then becoming northeast 10 to 20 knots late.
Isolated thunderstorms through early afternoon. Scattered
showers. Waves building to 3 to 5 feet occasionally to 7 feet.
.TONIGHT...Northeast winds 10 to 20 knots backing north after
midnight, then diminishing to 5 to 15 knots late. Isolated
showers through midnight. Waves subsiding to 1 to 3 feet.
.MONDAY...North winds 5 to 15 knots backing northwest in the
afternoon. Waves subsiding to calm to 2 feet.
.MONDAY NIGHT...South winds 5 to 15 knots. Waves calm to 2 feet.
.TUESDAY...South winds 5 to 15 knots increasing to 10 to 20 knots
by mid afternoon. Waves building to 1 to 3 feet.
.TUESDAY NIGHT...South winds 15 to 25 knots. A chance of showers
through midnight, then showers likely and a chance of
thunderstorms after midnight. Waves building to 2 to 4 feet, then
subsiding to 1 to 3 feet.
.WEDNESDAY...West winds 10 to 20 knots veering northwest. A
chance of showers and thunderstorms. Waves subsiding to calm to
2 feet.
.THURSDAY...Northwest winds 10 to 20 knots veering north. Waves
calm to 2 feet.

$$

LSZ267-231615-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
408 AM EDT Sun Jul 23 2017

.EARLY THIS MORNING...East winds 15 to 25 knots. Patchy fog.
Numerous showers and thunderstorms. Waves calm to 2 feet building
to 1 to 3 feet.
.TODAY...East winds 15 to 25 knots backing northeast late.
Numerous showers and isolated thunderstorms through early
afternoon, then scattered showers by mid afternoon. Waves
1 to 3 feet.
.TONIGHT...Northeast winds 15 to 25 knots becoming north 10 to
20 knots after midnight. Isolated showers. Waves subsiding calm
to 2 feet.
.MONDAY...North winds 10 to 20 knots backing northwest in the
afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...Northwest winds 5 to 15 knots backing south after
midnight. Waves calm to 2 feet.
.TUESDAY...South winds 5 to 15 knots increasing to 10 to 20 knots
by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...South winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Showers likely after midnight. Waves
building to 2 to 4 feet, then subsiding to 1 to 3 feet.
.WEDNESDAY...Southwest winds 10 to 20 knots veering west. Showers
likely. Waves subsiding to calm to 2 feet.
.THURSDAY...Northwest winds 10 to 20 knots veering north. Waves
calm to 2 feet.

$$

LSZ261-231615-
MAFOR 2309/
Superior West 11800 11810 11820 13120 11100 11800. Patchy fog
through mid morning. Scattered showers through mid morning. Waves
1 to 4 feet.

Superior North Central 11210 13120 11110 11800 11710 11700.
Patchy fog this morning. Scattered showers through early
afternoon. Waves 1 to 3 feet.

Superior South Central 11610 11720 11730 11130 11120 11110 12810.
Patchy fog this morning. Scattered showers today. Waves 2 to 5
feet.

Superior East 11236 12226 14120 11110. Patchy fog this morning.
Scattered showers this afternoon. Waves 1 to 3 feet.

$$

JLA

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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