979
FZUS63 KMQT 172009
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
409 PM EDT Fri May 17 2024

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 29.7 inch low pressure just northeast of Lake
Superior weakens to 29.8 inches and shifts northward over James
Bay tonight. Meanwhile, a weak 29.8 inch high pressure ridge will
drift across the western Great Lakes. As the ridge builds to 29.9
inches while shifting toward the Lower Great Lakes on Saturday, a
29.3 inch low over southern Manitoba will push an associated 29.6
inch trough eastward to western Lake Superior late in the
afternoon. This trough will weaken to 29.9 inches while sailing
across the rest of Lake Superior during Saturday night. The parent
low pressure that was over southern Manitoba on Saturday will
weaken to 29.6 inches as it moves over far northern Ontario during
Sunday. To its south, look for a 30.0 inch high pressure ridge to
settle over the Upper Great Lakes. As this ridge builds to 30.1
inches while quickly shifting to the Mid-Atlantic Coast on Monday,
a 29.8 inch trough will develop northeast to Lake Superior and
Upper Michigan. On Tuesday, a 29.4 inch low pressure will track
northeast to the Upper Mississippi Valley. This low deepens to
29.3 inches, centering over Upper Michigan early Wednesday.

LSZ162-180415-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
409 PM EDT Fri May 17 2024 /309 PM CDT Fri May 17 2024/

.LATE THIS AFTERNOON...Northeast winds 10 to 20 knots. A slight
chance of showers and thunderstorms. Waves 2 to 4 feet.
.TONIGHT...Northeast winds 10 to 20 knots veering east late. A
slight chance of showers and thunderstorms. Waves subsiding to
1 to 3 feet, then building to 2 to 4 feet.
.SATURDAY...East winds 10 to 20 knots increasing to 15 to
25 knots in the afternoon, then veering west late. A chance of
showers and a slight chance of thunderstorms. Waves 1 to 3 feet.
.SATURDAY NIGHT...West winds 15 to 25 knots diminishing to 10 to
20 knots after midnight, then backing southwest late. Waves
building to 2 to 4 feet, then subsiding to calm to 2 feet.
.SUNDAY...Southwest winds 10 to 20 knots. Waves building to 1 to
3 feet.
.SUNDAY NIGHT...South winds 10 to 20 knots backing northeast
after midnight. A chance of showers. Waves subsiding to calm to
2 feet.
.MONDAY...East winds 10 to 20 knots backing northeast by mid
afternoon. A chance of showers. Waves calm to 2 feet.
.MONDAY NIGHT...Northeast winds 5 to 15 knots. Waves calm to
2 feet.
.TUESDAY...Northeast winds 10 to 20 knots increasing to 15 to
25 knots. A chance of showers. Waves building to 2 to 4 feet.
.WEDNESDAY...West winds 15 to 25 knots becoming northwest 10 to
20 knots. A chance of rain showers. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 1 to 3 feet.

$$

LSZ263-180415-
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 Fri May 17 2024

.LATE THIS AFTERNOON...East winds 5 to 15 knots. A slight chance
of showers and thunderstorms. Waves calm to 2 feet.
.TONIGHT...East winds 5 to 15 knots. A slight chance of showers
and thunderstorms. Waves building to 2 to 4 feet, then subsiding
to 1 to 3 feet.
.SATURDAY...South winds 5 to 15 knots becoming southeast 10 to
20 knots in the afternoon, then veering southwest late. A slight
chance of rain showers through early afternoon. A slight chance
of thunderstorms. Rain showers likely by mid afternoon. Waves
1 to 3 feet.
.SATURDAY NIGHT...West winds 10 to 20 knots becoming southwest
5 to 15 knots late. A chance of rain showers and a slight chance
of thunderstorms through midnight. Waves 1 to 3 feet.
.SUNDAY...Southwest winds 10 to 20 knots. Waves building to 2 to
4 feet.
.SUNDAY NIGHT...South winds 5 to 15 knots. A chance of showers.
Waves subsiding to calm to 2 feet.
.MONDAY...Southeast winds 5 to 15 knots backing northeast by mid
afternoon. A chance of showers. Waves calm to 2 feet.
.MONDAY NIGHT...Northeast winds 5 to 15 knots. Waves calm to
2 feet.
.TUESDAY...Northeast winds 5 to 15 knots increasing to 10 to
20 knots. A chance of showers. Waves building to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of rain showers. Waves subsiding to 1 to
3 feet.

$$

LSZ264-180415-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
409 PM EDT Fri May 17 2024

.LATE THIS AFTERNOON...Southeast winds 5 to 15 knots. Patchy fog.
A slight chance of rain showers. Waves calm to 2 feet.
.TONIGHT...East winds 10 to 20 knots becoming southeast 5 to
15 knots late. A chance of rain showers and a slight chance of
thunderstorms. Waves building to 2 to 4 feet.
.SATURDAY...Southeast winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon. A chance of showers. A slight chance
of thunderstorms by mid afternoon. Waves building to 3 to 5 feet
occasionally to 7 feet.
.SATURDAY NIGHT...Southwest winds 10 to 20 knots veering west
after midnight, then becoming southwest 5 to 15 knots late. Rain
showers likely and a slight chance of thunderstorms through
midnight. Waves subsiding to 1 to 3 feet.
.SUNDAY...Southwest winds 10 to 20 knots. Waves building to 2 to
4 feet.
.SUNDAY NIGHT...South winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.MONDAY...Southeast winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.MONDAY NIGHT...Southeast winds 5 to 15 knots backing northeast
after midnight. Waves calm to 2 feet.
.TUESDAY...Northeast winds 5 to 15 knots increasing to 15 to
25 knots. A chance of showers. Waves building to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of rain showers. Waves subsiding to 2 to
4 feet.

$$

LSZ265-180415-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
409 PM EDT Fri May 17 2024

.LATE THIS AFTERNOON...East winds 10 to 20 knots. A slight chance
of showers. Waves calm to 2 feet.
.TONIGHT...Southeast winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. A slight chance of showers and
thunderstorms after midnight. Waves building to 1 to 3 feet.
.SATURDAY...Southeast winds 10 to 20 knots increasing to 15 to
25 knots in the afternoon. A chance of showers and a slight
chance of thunderstorms by mid afternoon. Waves 1 to 3 feet.
.SATURDAY NIGHT...Southwest winds 10 to 20 knots veering west
after midnight. Showers likely and a chance of thunderstorms
through midnight. Waves subsiding to calm to 2 feet.
.SUNDAY...Southwest winds 5 to 15 knots becoming south 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...South winds 10 to 20 knots. A chance of showers
after midnight. Waves calm to 2 feet.
.MONDAY...Southeast winds 10 to 20 knots. Showers likely through
early afternoon. A chance of showers by mid afternoon. Waves calm
to 2 feet.
.MONDAY NIGHT...East winds 5 to 15 knots backing northeast after
midnight. A chance of rain showers. Waves calm to 2 feet.
.TUESDAY...Northeast winds 5 to 15 knots increasing to 10 to
20 knots. A chance of showers, then showers likely late. A chance
of thunderstorms. Waves building to 1 to 3 feet.
.WEDNESDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of rain showers. Waves building to 2 to
4 feet, then subsiding to calm to 2 feet.

$$

LSZ266-180415-
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 Fri May 17 2024

.LATE THIS AFTERNOON...East winds 5 to 15 knots. Patchy fog. A
slight chance of rain showers. Waves calm to 2 feet.
.TONIGHT...East winds 10 to 20 knots veering south late. Patchy
fog through midnight. A slight chance of rain showers. A slight
chance of thunderstorms after midnight. Waves building to 2 to
4 feet.
.SATURDAY...South winds 10 to 20 knots becoming southeast 15 to
25 knots in the afternoon, then veering south late. A slight
chance of showers and thunderstorms by mid afternoon. Waves
building to 3 to 5 feet occasionally to 7 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight, then becoming west 5 to 15 knots late. Showers
likely and a slight chance of thunderstorms through midnight.
Waves subsiding to 1 to 3 feet.
.SUNDAY...Southwest winds 5 to 15 knots backing south by mid
afternoon. Waves 1 to 3 feet.
.SUNDAY NIGHT...South winds 10 to 20 knots. Waves subsiding to
calm to 2 feet.
.MONDAY...Southeast winds 10 to 20 knots. Showers likely. Waves
calm to 2 feet.
.MONDAY NIGHT...Southeast winds 5 to 15 knots backing northeast
after midnight. A chance of rain showers. Waves calm to 2 feet.
.TUESDAY...Northeast winds 5 to 15 knots becoming east 10 to
20 knots. A chance of showers, then showers likely late. A chance
of thunderstorms. Waves building to 2 to 4 feet.
.WEDNESDAY...West winds 15 to 25 knots. A chance of rain showers.
Waves building to 3 to 5 feet occasionally to 7 feet, then
subsiding to 2 to 4 feet.

$$

LSZ267-180415-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
409 PM EDT Fri May 17 2024

.LATE THIS AFTERNOON...East winds 5 to 15 knots. Patchy fog.
Waves calm to 2 feet.
.TONIGHT...East winds 5 to 15 knots becoming southeast 10 to
20 knots after midnight. Patchy fog. Waves calm to 2 feet.
.SATURDAY...Southeast winds 10 to 20 knots. Waves building to
1 to 3 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots becoming west 5 to
15 knots late. Showers likely and a slight chance of
thunderstorms. Waves subsiding to calm to 2 feet.
.SUNDAY...West winds 5 to 15 knots backing south by mid
afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...South winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Waves calm to 2 feet.
.MONDAY...Southeast winds 10 to 20 knots. Showers likely. Waves
calm to 2 feet.
.MONDAY NIGHT...Southeast winds 10 to 20 knots becoming northeast
5 to 15 knots after midnight. A chance of showers. Waves calm to
2 feet.
.TUESDAY...Northeast winds 10 to 20 knots veering southeast. A
chance of showers, then showers likely late. A chance of
thunderstorms. Waves building to 1 to 3 feet.
.WEDNESDAY...West winds 15 to 25 knots. A chance of showers.
Waves building to 2 to 4 feet.

$$

LSZ261-180415-
MAFOR 1721/
Superior West 11120 13220 12210 11310 11410. A chance of showers
Saturday afternoon. Waves 1 to 4 feet.

Superior North Central 11310 12320 11220 13320 11330. A chance of
rain showers tonight. Waves 1 to 4 feet.

Superior South Central 11210 19213 13320 11420 12320 11330. Waves
1 to 3 feet.

Superior East 12210 19213 14310 11310 11320. Waves 1 to 3 feet.

$$

BW

Experimental modernized open lake forecast is available online at
weather.gov/mqt/glftable

Graphical marine forecasts are available online at:
weather.gov/greatlakes