National Weather Service Marine Forecast FZUS63 KMQT

FZUS63 KMQT 150756
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
356 AM EDT Thu Apr 15 2021

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 broad 29.8 inch low centered over he St Lawrence
Valley is expected to deepen slightly to 29.7 inches today while
remaining in place or drifting slightly westward back towards Lake
Ontario. At the same time, a 30.4 inch ridge extends from the
Northern Plains northward through the Canadian prairies to Hudson
Bay. This ridge will remain in place through Friday before slowly
drifting south towards the Rockies on Saturday and weakening to
30.3 inches. On Sunday a 29.8 inch trough will develop over the
Northern Plains. This trough will track east into the Upper Great
Lakes by Monday.

LSZ162-151600-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
356 AM EDT Thu Apr 15 2021 /256 AM CDT Thu Apr 15 2021/

EARLY THIS MORNING
North winds 5 to 15 knots. Waves 1 to
3 feet.

TODAY
North winds 5 to 15 knots backing southwest in the
afternoon. Waves subsiding to calm to 2 feet.

TONIGHT
West winds 5 to 15 knots veering northeast after
midnight, then backing north late. Waves calm to 2 feet.

FRIDAY
North winds 5 to 15 knots backing south in the
afternoon. Waves calm to 2 feet.

FRIDAY NIGHT
East winds 5 to 15 knots backing north after
midnight. Waves calm to 2 feet.

SATURDAY
North winds 5 to 15 knots veering south by mid
afternoon. Waves calm to 2 feet.

SATURDAY NIGHT
West winds 5 to 15 knots veering northwest
after midnight. Waves calm to 2 feet.

SUNDAY
Southwest winds 5 to 15 knots becoming northeast 15 to
25 knots. A chance of rain showers, possibly mixed with snow.
Waves building to 1 to 3 feet.

MONDAY
North winds 15 to 25 knots becoming northwest 10 to
20 knots. A chance of rain showers. A chance of snow showers.
Waves building to 2 to 4 feet, then subsiding to calm to 2 feet.

LSZ263-151600-
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-
356 AM EDT Thu Apr 15 2021

EARLY THIS MORNING
North winds 15 to 25 knots. Waves 3 to
6 feet occasionally to 8 feet.

TODAY
North winds 15 to 25 knots diminishing to 10 to 20 knots
in the afternoon, then becoming west 5 to 15 knots late. Waves
subsiding to 1 to 3 feet.

TONIGHT
West winds 5 to 15 knots veering north after midnight.
Waves subsiding to calm to 2 feet, then building to 1 to 3 feet.

FRIDAY
North winds 10 to 20 knots diminishing to 5 to 15 knots
in the afternoon, then veering south late. Waves subsiding to
calm to 2 feet.

FRIDAY NIGHT
Northwest winds 5 to 15 knots veering north after
midnight. Waves calm to 2 feet.

SATURDAY
North winds 5 to 15 knots backing southwest by mid
afternoon. Waves calm to 2 feet.

SATURDAY NIGHT
Southwest winds 5 to 15 knots veering northwest
after midnight. Waves calm to 2 feet.

SUNDAY
Southwest winds 5 to 15 knots becoming northeast 10 to
20 knots. A chance of rain showers, possibly mixed with snow.
Waves building to 1 to 3 feet.

MONDAY
North winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of snow showers. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to calm to 2 feet.

LSZ264-151600-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
356 AM EDT Thu Apr 15 2021

EARLY THIS MORNING
North winds 15 to 25 knots. Waves 4 to
8 feet occasionally to 10 feet.

TODAY
North winds 15 to 25 knots diminishing to 10 to 20 knots
late. Waves subsiding to 3 to 5 feet occasionally to 7 feet.

TONIGHT
North winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves subsiding to 2 to 4 feet.

FRIDAY
North winds 10 to 20 knots diminishing to 5 to 15 knots
in the afternoon. Waves subsiding to calm to 2 feet.

FRIDAY NIGHT
Northwest winds 5 to 15 knots veering north after
midnight. Waves calm to 2 feet.

SATURDAY
North winds 5 to 15 knots backing west by mid
afternoon. Waves calm to 2 feet.

SATURDAY NIGHT
West winds 5 to 15 knots veering northwest
after midnight. Waves calm to 2 feet.

SUNDAY
West winds 5 to 15 knots becoming northeast 10 to
20 knots. A chance of snow showers. Waves building to 1 to
3 feet.

MONDAY
North winds 15 to 25 knots diminishing to 10 to
20 knots. Waves building to 3 to 5 feet occasionally to 7 feet,
then subsiding to 1 to 3 feet.

LSZ265-151600-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
356 AM EDT Thu Apr 15 2021

EARLY THIS MORNING
North winds 15 to 25 knots. Patchy drizzle.
Waves 6 to 9 feet occasionally to 11 feet.

TODAY
North winds 20 to 30 knots diminishing to 15 to 25 knots
in the afternoon, then backing northwest late. Patchy drizzle
through early afternoon. Waves subsiding to 4 to 7 feet
occasionally to 9 feet.

TONIGHT
North winds 10 to 20 knots. Waves subsiding to 3 to
5 feet occasionally to 7 feet.

FRIDAY
North winds 10 to 20 knots diminishing to 5 to 15 knots
late. Waves subsiding to 2 to 4 feet.

FRIDAY NIGHT
Northwest winds 5 to 15 knots veering north after
midnight. Waves subsiding to calm to 2 feet.

SATURDAY
North winds 5 to 15 knots. Waves calm to 2 feet.

SATURDAY NIGHT
Northwest winds 5 to 15 knots backing west
after midnight. Waves calm to 2 feet.

SUNDAY
Northwest winds 5 to 15 knots backing southeast. A
chance of rain showers. Waves calm to 2 feet.

MONDAY
North winds 15 to 25 knots becoming northwest 10 to
20 knots. A chance of rain showers. A chance of snow showers.
Waves building to 3 to 5 feet occasionally to 7 feet, then
subsiding to 1 to 3 feet.

LSZ266-151600-
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-
356 AM EDT Thu Apr 15 2021

EARLY THIS MORNING
North winds 20 to 30 knots. Waves 8 to
11 feet occasionally to 14 feet subsiding to 7 to 10 feet
occasionally to 13 feet.

TODAY
North winds 20 to 30 knots. Patchy drizzle through early
afternoon. Waves subsiding to 6 to 9 feet occasionally to
11 feet.

TONIGHT
North winds 15 to 25 knots. Waves subsiding to 3 to
5 feet occasionally to 7 feet.

FRIDAY
North winds 15 to 25 knots becoming northwest 10 to
20 knots late. Waves subsiding to 2 to 4 feet.

FRIDAY NIGHT
Northwest winds 10 to 20 knots veering north
after midnight. Waves subsiding to calm to 2 feet.

SATURDAY
North winds 10 to 20 knots backing northwest by mid
afternoon. Waves calm to 2 feet.

SATURDAY NIGHT
Northwest winds 5 to 15 knots. Waves calm to
2 feet.

SUNDAY
Northwest winds 5 to 15 knots becoming south 10 to
20 knots. Waves calm to 2 feet.

MONDAY
Northwest winds 15 to 25 knots veering north. A chance
of rain showers. A chance of snow showers. Waves building to 3 to
5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet.

LSZ267-151600-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
356 AM EDT Thu Apr 15 2021

EARLY THIS MORNING
North winds 20 to 30 knots. Waves 4 to
7 feet occasionally to 9 feet.

TODAY
North winds 20 to 30 knots backing northwest late.
Patchy drizzle. Waves building to 5 to 8 feet occasionally to
10 feet.

TONIGHT
North winds 15 to 25 knots. Waves subsiding to 2 to
4 feet.

FRIDAY
North winds 15 to 25 knots backing northwest late.
Waves subsiding to 1 to 3 feet, then building to 2 to 4 feet.

FRIDAY NIGHT
North winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.

SATURDAY
North winds 5 to 15 knots becoming northwest 10 to
20 knots by mid afternoon. Waves calm to 2 feet.

SATURDAY NIGHT
Northwest winds 10 to 20 knots diminishing to
5 to 15 knots after midnight. Waves calm to 2 feet.

SUNDAY
Northwest winds 5 to 15 knots backing south. Waves calm
to 2 feet.

MONDAY
Northwest winds 10 to 20 knots becoming north 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.

LSZ261-151600-
MAFOR 1509/
Superior West 12820 11710 11600 11510 11500 11200 11100. Waves 1
to 4 feet today. Waves around 1 foot tonight.

Superior North Central 11840 13830 14820. Waves 5 to 8 feet
today. Waves 2 to 5 feet tonight.

Superior South Central 12840 11845 12740 11830 12820. Waves 6 to
10 feet today. Waves 5 to 8 feet subsiding to 3 to 6 feet
tonight.

Superior East 12830 11840 12740 11830 12820. Waves 5 to 8 feet
today. Waves 5 to 8 feet subsiding to 3 to 5 feet tonight.

RJC

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

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