Great Lakes Forecast
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FZUS63 KMQT 181350
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
950 AM EDT Tue Jul 18 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 29.8 inch trough will move across Lake Superior
today into Wednesday. The trough will settle south of Lake
Superior on Thursday while a 30.0 inch ridge builds over the Upper
Great Lakes. On Friday another trough at 29.8 inches will track
across the Upper Great Lakes as the ridge builds over the Ohio
Valley. On Saturday morning a 29.6 inch low over the Mid
Mississippi Valley tracks to Southern Lake Michigan through
Saturday as an associated 29.7 inch trough moves over the Upper
Great Lakes.

LSZ162-182200-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
950 AM EDT Tue Jul 18 2017 /850 AM CDT Tue Jul 18 2017/

.REST OF TODAY...West winds 5 to 15 knots. Patchy fog by late
morning. A slight chance of thunderstorms by late morning. A
slight chance of showers. Waves calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots. Waves calm to 2 feet.
.WEDNESDAY...West winds 5 to 15 knots backing south late. Waves
calm to 2 feet.
.WEDNESDAY NIGHT...South winds 5 to 15 knots veering southwest
after midnight. A slight chance of showers after midnight. Waves
calm to 2 feet.
.THURSDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots veering northwest
after midnight. Waves calm to 2 feet.
.FRIDAY...Northeast winds 5 to 15 knots veering east. Waves calm
to 2 feet.
.SATURDAY...East winds 5 to 15 knots backing north. A chance of
showers and thunderstorms. Waves calm to 2 feet.

$$

LSZ263-182200-
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-
950 AM EDT Tue Jul 18 2017

.REST OF TODAY...West winds 5 to 15 knots. Patchy fog by late
morning. A slight chance of thunderstorms by late morning. A
slight chance of showers. Waves calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots. Waves calm to 2 feet.
.WEDNESDAY...West winds 5 to 15 knots backing southwest in the
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...South winds 5 to 15 knots veering southwest
after midnight. A slight chance of showers after midnight. Waves
calm to 2 feet.
.THURSDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots becoming west
less than 10 knots after midnight. Waves calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots backing northeast. A chance
of showers and thunderstorms. Waves building to 1 to 3 feet.

$$

LSZ264-182200-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
950 AM EDT Tue Jul 18 2017

.REST OF TODAY...West winds 5 to 15 knots backing southwest in
the afternoon. Patchy fog by late morning. A slight chance of
thunderstorms by late morning. A slight chance of showers. Waves
calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots. Waves calm to 2 feet.
.WEDNESDAY...Northwest winds 5 to 15 knots backing southwest
late. Waves calm to 2 feet.
.WEDNESDAY NIGHT...South winds 5 to 15 knots veering southwest
after midnight. A slight chance of showers after midnight. Waves
calm to 2 feet.
.THURSDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots becoming west
less than 10 knots after midnight. Waves calm to 2 feet.
.FRIDAY...East winds less than 10 knots increasing to 5 to
15 knots. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots. A chance of showers, then
showers likely and a chance of thunderstorms. Waves building to
1 to 3 feet.

$$

LSZ265-182200-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
950 AM EDT Tue Jul 18 2017

.REST OF TODAY...Southwest winds 5 to 15 knots diminishing to
less than 10 knots in the afternoon, then backing northeast late.
A chance of showers and thunderstorms. Waves calm to 2 feet.
.TONIGHT...Southwest winds less than 10 knots becoming west 5 to
15 knots after midnight, then increasing to 10 to 20 knots late.
A slight chance of showers and thunderstorms through midnight.
Waves calm to 2 feet.
.WEDNESDAY...West winds 10 to 20 knots veering northwest in the
afternoon, then becoming east 5 to 15 knots late. Waves calm to
2 feet.
.WEDNESDAY NIGHT...South winds 5 to 15 knots increasing to 10 to
20 knots after midnight. A slight chance of showers after
midnight. Waves calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots becoming south 5 to
15 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots veering west
after midnight. Waves calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots increasing to 10 to 20 knots.
Waves calm to 2 feet.
.SATURDAY...East winds 10 to 20 knots. A chance of showers, then
showers likely and a chance of thunderstorms. Waves building to
1 to 3 feet.

$$

LSZ266-182200-
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-
950 AM EDT Tue Jul 18 2017

.REST OF TODAY...Southwest winds 10 to 20 knots diminishing to
5 to 15 knots in the afternoon, then veering west late. Patchy
fog by late morning. A chance of showers and thunderstorms. Waves
1 to 3 feet subsiding to calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots. A slight chance of
thunderstorms through midnight. A chance of showers. Waves calm
to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots becoming west 5 to
15 knots late. Waves calm to 2 feet.
.WEDNESDAY NIGHT...South winds 5 to 15 knots increasing to 10 to
20 knots after midnight. A slight chance of showers after
midnight. Waves calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots becoming south 5 to
15 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots veering west
after midnight. Waves calm to 2 feet.
.FRIDAY...North winds 5 to 15 knots veering east. Waves calm to
2 feet.
.SATURDAY...East winds 10 to 20 knots. Showers likely and a
chance of thunderstorms. Waves building to 1 to 3 feet.

$$

LSZ267-182200-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
950 AM EDT Tue Jul 18 2017

.REST OF TODAY...South winds 10 to 20 knots diminishing to 5 to
15 knots in the afternoon. A chance of showers. A chance of
thunderstorms by mid afternoon. Waves 1 to 3 feet subsiding to
calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots. A chance of thunderstorms
through midnight. A chance of showers. Waves calm to 2 feet.
.WEDNESDAY...West winds 10 to 20 knots diminishing to 5 to
15 knots late. Waves calm to 2 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots backing south after
midnight. Waves calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots veering west
after midnight. Waves calm to 2 feet.
.FRIDAY...North winds 5 to 15 knots. Waves calm to 2 feet.
.SATURDAY...East winds 10 to 20 knots. Showers likely. Waves
building to 1 to 3 feet.

$$
LSZ261-182200-
MAFOR 1815/
Superior West 16600. Waves around 1 foot.

Superior North Central 11610 11500 12600 12610 12710. Patchy fog
late this morning. Chance of showers and thunderstorms late this
morning. Waves 1 to 2 feet.

Superior South Central 11400 11300 11100 11400 11600 12610 11710.
Chance of showers and thunderstorms this afternoon through early
this evening. Waves 2 feet or less.

Superior East 11510 11500 14600 12700. Chance of showers and
thunderstorms late this afternoon through early this evening.
Chance of showers tonight. 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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