388
FZUS63 KMQT 192214
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
614 PM EDT Thu Sep 19 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 29.3 inch low pressure over Lake Winnipeg sends a
29.7 inch trough sweeping east into Lake Superior this evening. As
the low continues to track northeast to Hudson Bay on Friday, the
associated trough will fill to 29.8 inches as it moves over
western Lake Superior. This trough will then dissipate, allowing
weak 29.9 inch ridging to anchor over the Upper Great Lakes on
Saturday morning. A new low pressure of 29.6 inches over southern
Manitoba Saturday morning will then track across far northern
Ontario Saturday afternoon and night. Its associated 29.9 inch
trough will sweep across Lake Superior during Saturday night and
Sunday morning. In its wake, 30.1 inch high pressure will build
from the Northern Plains into northern Ontario during Sunday and
Monday. Also on Monday, a 29.7 inch low pressure will track
northeast to southern Wisconsin. 30.0 inch high pressure builds
over the Lower MS Valley Tuesday.

LSZ162-200615-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
614 PM EDT Thu Sep 19 2024 /514 PM CDT Thu Sep 19 2024/

...TORNADO WATCH 678 IN EFFECT UNTIL MIDNIGHT EDT /11 PM CDT/
TONIGHT...

.LATE THIS AFTERNOON...East winds 10 to 20 knots. Scattered
showers and thunderstorms. Some thunderstorms may be severe with
wind gusts over 35 knots, large hail, and tornadoes. Waves calm
to 2 feet.
.TONIGHT...South winds 10 to 20 knots veering southwest after
midnight. A chance of showers and thunderstorms. Some thunderstorms
may be severe with wind gusts over 35 knots, large hail, and
tornadoes through late evening. Waves building to 1 to 3 feet,
then subsiding to calm to 2 feet.
.FRIDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon. Waves building to 1 to 3 feet.
.FRIDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm
to 2 feet.
.SATURDAY...South winds 5 to 15 knots increasing to 10 to
20 knots by mid afternoon. A slight chance of showers and
thunderstorms by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Northwest winds 10 to 20 knots. A chance of
showers. Waves calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots backing west by mid
afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...North winds 10 to 20 knots. Waves calm to 2 feet.
.MONDAY...Northeast winds 10 to 20 knots. Waves building to 1 to
3 feet, then subsiding to calm to 2 feet.
.TUESDAY...North winds 10 to 20 knots backing west. Waves calm to
2 feet.

$$

LSZ263-200615-
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-
614 PM EDT Thu Sep 19 2024

.LATE THIS AFTERNOON...Southeast winds 10 to 20 knots. Isolated
showers and thunderstorms. Waves 1 to 3 feet.
.TONIGHT...South winds 10 to 20 knots. A chance of showers and
thunderstorms. Waves building to 2 to 4 feet, then subsiding to
1 to 3 feet.
.FRIDAY...Southwest winds 5 to 15 knots veering west late. A
slight chance of showers and thunderstorms through early
afternoon. Waves 1 to 3 feet.
.FRIDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm
to 2 feet.
.SATURDAY...South winds 5 to 15 knots. A slight chance of showers
by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. A chance of showers. Waves building to 1 to
3 feet.
.SUNDAY...Northwest winds 10 to 20 knots. Waves subsiding to calm
to 2 feet.
.SUNDAY NIGHT...Northwest winds 5 to 15 knots veering north after
midnight. Waves calm to 2 feet.
.MONDAY...Northeast winds 10 to 20 knots. Waves building to 1 to
3 feet, then subsiding to calm to 2 feet.
.TUESDAY...North winds 10 to 20 knots becoming west 5 to
15 knots. Waves calm to 2 feet.

$$

LSZ264-200615-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
614 PM EDT Thu Sep 19 2024

.LATE THIS AFTERNOON...Southeast winds 10 to 20 knots. Isolated
showers. Waves 2 to 4 feet.
.TONIGHT...Southeast winds 15 to 25 knots veering south after
midnight, then diminishing to 10 to 20 knots late. A chance of
showers and thunderstorms. Waves building to 3 to 6 feet
occasionally to 8 feet.
.FRIDAY...South winds 5 to 15 knots veering southwest in the
afternoon. A slight chance of showers and thunderstorms through
early afternoon. Waves subsiding to 1 to 3 feet.
.FRIDAY NIGHT...Southwest winds 5 to 15 knots veering northwest
late. Waves subsiding to calm to 2 feet.
.SATURDAY...South winds 5 to 15 knots backing southeast by mid
afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots veering northwest
after midnight. A chance of showers. Waves building to 1 to
3 feet.
.SUNDAY...Northwest winds 10 to 20 knots. Waves subsiding to calm
to 2 feet.
.SUNDAY NIGHT...Northwest winds 5 to 15 knots veering north after
midnight. Waves calm to 2 feet.
.MONDAY...Northeast winds 10 to 20 knots diminishing to 5 to
15 knots. A chance of showers. Waves building to 1 to 3 feet,
then subsiding to calm to 2 feet.
.TUESDAY...Northeast winds 5 to 15 knots backing west. Waves calm
to 2 feet.

$$

LSZ265-200615-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
614 PM EDT Thu Sep 19 2024

.LATE THIS AFTERNOON...Southeast winds 15 to 25 knots. Isolated
showers. Waves 2 to 4 feet.
.TONIGHT...Southeast winds 15 to 25 knots. A chance of showers
and thunderstorms. Waves building to 3 to 5 feet occasionally to
7 feet, then subsiding to 2 to 4 feet.
.FRIDAY...South winds 5 to 15 knots. A slight chance of showers
and thunderstorms. Waves subsiding to calm to 2 feet.
.FRIDAY NIGHT...Southwest winds 5 to 15 knots veering west after
midnight. Waves calm to 2 feet.
.SATURDAY...West winds 5 to 15 knots becoming southeast 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots veering northwest
after midnight. A chance of showers. Waves calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.
.SUNDAY NIGHT...North winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.
.MONDAY...Northeast winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.
.TUESDAY...North winds 10 to 20 knots backing west. A chance of
showers. Waves calm to 2 feet.

$$

LSZ266-200615-
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-
614 PM EDT Thu Sep 19 2024

.LATE THIS AFTERNOON...Southeast winds 15 to 25 knots. Waves 2 to
4 feet.
.TONIGHT...South winds 15 to 25 knots. A chance of showers and
thunderstorms. Waves building to 3 to 6 feet occasionally to
8 feet.
.FRIDAY...South winds 15 to 25 knots diminishing to 5 to 15 knots
in the afternoon. A chance of showers and thunderstorms. Waves
subsiding to 1 to 3 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots veering west late. A
slight chance of showers and thunderstorms through midnight.
Waves subsiding to calm to 2 feet.
.SATURDAY...West winds 5 to 15 knots backing southeast by mid
afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots veering west after
midnight. A chance of showers. Waves building to 1 to 3 feet.
.SUNDAY...Northwest winds 10 to 20 knots. A chance of showers.
Waves subsiding to calm to 2 feet.
.SUNDAY NIGHT...North winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.
.MONDAY...Northeast winds 10 to 20 knots. A chance of showers.
Waves building to 1 to 3 feet, then subsiding to calm to 2 feet.
.TUESDAY...North winds 10 to 20 knots backing northwest. A chance
of showers. Waves calm to 2 feet.

$$

LSZ267-200615-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
614 PM EDT Thu Sep 19 2024

.LATE THIS AFTERNOON...Southeast winds 10 to 20 knots. Waves calm
to 2 feet.
.TONIGHT...South winds 10 to 20 knots backing southeast after
midnight, then increasing to 15 to 25 knots late. A chance of
showers and a slight chance of thunderstorms after midnight.
Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet.
.FRIDAY...Southeast winds 15 to 25 knots becoming south 10 to
20 knots late. A chance of showers and thunderstorms. Waves
subsiding to 1 to 3 feet.
.FRIDAY NIGHT...South winds 10 to 20 knots diminishing to 5 to
15 knots after midnight, then veering southwest late. A chance of
showers and thunderstorms through midnight. Waves subsiding to
calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots backing southeast by
mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots. A chance of
showers. Waves calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots. A chance of showers.
Waves building to 1 to 3 feet.
.SUNDAY NIGHT...North winds 10 to 20 knots. Showers likely
through midnight. A chance of showers after midnight. Waves
subsiding to 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, then
subsiding to calm to 2 feet.
.TUESDAY...East winds 10 to 20 knots backing northwest. A chance
of showers. Waves calm to 2 feet.

$$
LSZ261-200615-
MAFOR 1921 AMD/
Superior West...TORNADO WATCH IN EFFECT...11320 11420 19429 12520
19529 11520 11510 12520. Waves 1 to 3 feet.

Superior North Central 12330 11430 19439 11436 19439 11430 19439
11420 12510. Waves 2 to 4 feet building to 3 to 6 feet tonight.
Waves 3 to 5 feet subsiding to 2 to 4 feet Friday.

Superior South Central 11320 11330 11330 19339 11426 19429 11320
19329 12420 11300. Waves 2 to 4 feet tonight. Waves 1 to 3 feet
Friday.

Superior East 11310 11420 11320 12320 19326 12320 11420. Waves 1
to 3 feet building to 2 to 4 feet tonight. Waves 2 to 4 feet
Friday.

$$

07

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

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