National Weather Service Marine Forecast FZUS63 KMQT

FZUS63 KMQT 041348
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
948 AM EDT Fri Apr 4 2025

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
30.2 inch high pressure currently over the Upper Great Lakes builds to 30.4 inches throughout today. A weak 30.1 inch trough will move through late tonight followed by another weak 30.1 inch through Saturday night. Troughing deepens Sunday as a 29.9 inch low organizes near Lake Michigan, then presses east into Ontario and the lower Lakes Monday at 29.5 inches. Upstream on Monday, 30.5 inch high will build across the Plains, resulting in increasing pressure over Lake Superior. By Tuesday, this high will be 30.3 inches over much of the Upper Midwest.

LSZ162-042200
Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM
948 AM EDT Fri Apr 4 2025 /848 AM CDT Fri Apr 4 2025/

REST OF TODAY
Southwest winds 5 to 15 knots backing south in the afternoon. Waves calm to 2 feet.

TONIGHT
South winds 5 to 15 knots veering west after midnight, then becoming northwest 15 to 25 knots late. A chance of rain showers, possibly mixed with snow. Waves building to 2 to 4 feet.

SATURDAY
Northwest winds 15 to 25 knots backing west late. Waves subsiding to 1 to 3 feet.

SATURDAY NIGHT
West winds 10 to 20 knots. Waves subsiding to 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 15 to 25 knots. A chance of snow showers. Waves building to 3 to 5 feet occasionally to 7 feet.

MONDAY
North winds 15 to 25 knots diminishing to 10 to 20 knots. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet.

TUESDAY
Southwest winds 10 to 20 knots backing south. Waves calm to 2 feet.

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LSZ263-042200
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
948 AM EDT Fri Apr 4 2025

REST OF TODAY
Southwest winds less than 10 knots backing south in the afternoon, then increasing to 5 to 15 knots late. Waves calm to 2 feet.

TONIGHT
Southeast winds 5 to 15 knots veering west after midnight, then becoming northwest 10 to 20 knots late. A chance of rain showers. Snow showers likely after midnight. Waves building to 2 to 4 feet.

SATURDAY
Northwest winds 15 to 25 knots backing west late. A chance of snow showers through early afternoon. Waves building to 3 to 5 feet occasionally to 7 feet.

SATURDAY NIGHT
West winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to 2 to 4 feet.

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

SUNDAY NIGHT
North winds 15 to 25 knots. A chance of snow showers. Waves building to 3 to 5 feet occasionally to 7 feet.

MONDAY
North winds 15 to 25 knots diminishing to 10 to 20 knots. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to 1 to 3 feet.

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

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LSZ264-042200
Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border
948 AM EDT Fri Apr 4 2025

REST OF TODAY
Southwest winds less than 10 knots becoming south 5 to 15 knots late. Waves calm to 2 feet.

TONIGHT
Southeast winds 5 to 15 knots veering south after midnight, then becoming west 10 to 20 knots late. A chance of rain showers. Snow showers after midnight. Waves calm to 2 feet.

SATURDAY
Northwest winds 15 to 25 knots backing west late. A chance of snow showers. Waves building to 3 to 6 feet occasionally to 8 feet.

SATURDAY NIGHT
Northwest winds 15 to 25 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to 2 to 4 feet.

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

SUNDAY NIGHT
North winds 15 to 25 knots. Freezing spray after midnight. Waves building to 3 to 6 feet occasionally to 8 feet.

MONDAY
North winds 15 to 25 knots. Freezing spray. Waves building to 4 to 7 feet occasionally to 9 feet, then subsiding to 3 to 5 feet occasionally to 7 feet.

TUESDAY
Northwest winds 10 to 20 knots becoming southwest 5 to 15 knots. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet.

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LSZ265-042200
Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore
948 AM EDT Fri Apr 4 2025

REST OF TODAY
Southwest winds 5 to 15 knots backing southeast in the afternoon, then increasing to 10 to 20 knots late. Waves calm to 2 feet.

TONIGHT
Southeast winds 10 to 20 knots becoming south 5 to 15 knots after midnight, then veering west late. A chance of rain showers, possibly mixed with snow after midnight. Waves calm to 2 feet.

SATURDAY
Northwest winds 15 to 25 knots increasing to 20 to 30 knots in the afternoon, then becoming west to 30 knots with a few gale force gusts to 35 knots possible late. A chance of rain showers through early afternoon. A chance of snow showers. Waves building to 3 to 6 feet occasionally to 8 feet.

SATURDAY NIGHT
West winds 15 to 25 knots diminishing to 10 to 20 knots after midnight. Waves subsiding to calm to 2 feet.

SUNDAY
Northwest winds 10 to 20 knots. Waves calm to 2 feet.

SUNDAY NIGHT
North winds 10 to 20 knots increasing to 20 to 30 knots after midnight. A chance of snow showers. Waves building to 3 to 6 feet occasionally to 8 feet.

MONDAY
North winds 20 to 30 knots. Freezing spray. Waves building to 5 to 8 feet occasionally to 10 feet, then subsiding to 3 to 6 feet occasionally to 8 feet.

TUESDAY
Northwest winds 10 to 20 knots backing south. Waves subsiding to calm to 2 feet.

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LSZ266-042200
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
948 AM EDT Fri Apr 4 2025

REST OF TODAY
Southwest winds 5 to 15 knots backing southeast late. Waves calm to 2 feet.

TONIGHT
Southeast winds 10 to 20 knots becoming south 5 to 15 knots after midnight. A chance of rain showers, possibly mixed with freezing rain and snow showers after midnight. Waves calm to 2 feet.

SATURDAY
Northwest winds 15 to 25 knots increasing to 30 knots with a few gale force gusts to 35 knots possible. A chance of rain showers through early afternoon. A chance of snow showers. Waves building to 6 to 9 feet occasionally to 11 feet.

SATURDAY NIGHT
Northwest winds 15 to 25 knots diminishing to 10 to 20 knots after midnight. Waves subsiding to 3 to 5 feet occasionally to 7 feet.

SUNDAY
Northwest winds 10 to 20 knots. Waves subsiding to 2 to 4 feet.

SUNDAY NIGHT
North winds 15 to 25 knots. A chance of snow showers. Waves building to 3 to 6 feet occasionally to 8 feet.

MONDAY
North winds 20 to 30 knots. Freezing spray. Waves building to 7 to 10 feet occasionally to 13 feet, then subsiding to 4 to 7 feet occasionally to 9 feet.

TUESDAY
Northwest winds 15 to 25 knots becoming southwest 10 to 20 knots. Waves subsiding to calm to 2 feet.

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LSZ267-042200
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border
948 AM EDT Fri Apr 4 2025

REST OF TODAY
South winds 5 to 15 knots backing east late. Waves calm to 2 feet.

TONIGHT
Southeast winds 10 to 20 knots becoming south 5 to 15 knots late. Waves calm to 2 feet.

SATURDAY
West winds 10 to 20 knots becoming northwest 20 to 30 knots in the afternoon, then increasing to 30 knots with a few gale force gusts to 35 knots possible late. A chance of rain and snow showers, possibly mixed with freezing rain through early afternoon. Waves building to 6 to 9 feet occasionally to 11 feet.

SATURDAY NIGHT
Northwest winds 20 to 30 knots diminishing to 15 to 25 knots after midnight. Waves subsiding to 3 to 5 feet occasionally to 7 feet.

SUNDAY
Northwest winds 10 to 20 knots. Waves subsiding to 2 to 4 feet.

SUNDAY NIGHT
Northwest winds 15 to 25 knots veering north after midnight. Waves 2 to 4 feet.

MONDAY
North winds 20 to 30 knots. Freezing spray. Waves building to 7 to 10 feet occasionally to 13 feet, then subsiding to 3 to 6 feet occasionally to 8 feet.

TUESDAY
Northwest winds 15 to 25 knots diminishing to 10 to 20 knots. Waves subsiding to calm to 2 feet.

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LSZ261-042200
MAFOR 0415/ Superior West 11400 13300 11600 11720 12730. A chance of rain showers overnight. A chance of snow showers Saturday morning. Waves 1 foot or less this afternoon building to 1 to 3 feet tonight. Waves 2 to 4 feet Saturday morning.

Superior North Central 11500 12400 11310 11410 11517 11727 11730. A chance of rain showers overnight. Waves 2 feet or less this afternoon and tonight. Waves 2 to 4 feet building to 4 to 6 feet Saturday morning.

Superior South Central 11500 11300 12310 12410 11510 11730. A chance of rain showers overnight. A chance of rain showers, snow showers and light freezing rain Saturday morning. Waves 2 feet or less this afternoon and tonight. Waves 1 to 3 feet Saturday morning.

Superior East 12400 11300 12310 12410 11520. A chance of rain showers, light freezing rain and snow showers Saturday morning. Waves 1 to 2 feet.

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WFO MQT

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

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