FZUS63 KMQT 201934 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 334 PM EDT Thu Mar 20 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...A 30.4 inch high in southern Oklahoma extends a weak 29.9 inch ridge over Lake Superior into this evening. This ridge will be displaced by a 29.3 inch low over central Ontario Friday morning that moves a 29.5 inch trough across Lake Superior. On Saturday, the low is displaced by a 30.1 inch high moving directly over the lake. This high then moves out of Lake Superior Saturday night as a 29.4 inch low pressure organizes over the Northern Plains and pushes into the Upper Great Lakes Sunday night before leaving for the St. Lawrence Seaway late Monday. Ridging of at least 30.0 inches returns over Lake Superior Tuesday. LSZ162-210345- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 334 PM EDT Thu Mar 20 2025 /234 PM CDT Thu Mar 20 2025/ .LATE THIS AFTERNOON...Southwest winds 15 to 25 knots. Waves 2 to 4 feet. .TONIGHT...Southwest winds 20 to 30 knots diminishing to 15 to 25 knots late. Waves building to 3 to 6 feet occasionally to 8 feet. .FRIDAY...West winds 15 to 25 knots veering northwest in the afternoon. Waves subsiding to 1 to 3 feet, then building to 3 to 5 feet occasionally to 7 feet. .FRIDAY NIGHT...North winds 20 to 30 knots diminishing to 5 to 15 knots. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to 1 to 3 feet. .SATURDAY...North winds 5 to 15 knots veering south by mid afternoon. Waves subsiding to calm to 2 feet. .SATURDAY NIGHT...East winds 10 to 20 knots increasing to 15 to 25 knots after midnight. A chance of snow after midnight. Waves building to 2 to 4 feet. .SUNDAY...East winds 15 to 25 knots increasing to 20 to 30 knots by mid afternoon. Snow. Waves building to 4 to 7 feet occasionally to 9 feet. .SUNDAY NIGHT...Northeast winds 20 to 30 knots becoming north 15 to 25 knots after midnight. Snow likely through midnight, then a chance of snow after midnight. Waves subsiding to 3 to 6 feet occasionally to 8 feet. .MONDAY...North winds 10 to 20 knots backing northwest. Waves subsiding to calm to 2 feet. .TUESDAY...Southwest winds 10 to 20 knots veering northwest. Waves calm to 2 feet. $$ LSZ263-210345- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 334 PM EDT Thu Mar 20 2025 .LATE THIS AFTERNOON...Southwest winds 15 to 25 knots. Waves 2 to 4 feet building to 3 to 5 feet occasionally to 7 feet. .TONIGHT...Southwest winds 15 to 25 knots increasing to 20 to 30 knots after midnight. Waves building to 5 to 8 feet occasionally to 10 feet. .FRIDAY...West winds 20 to 30 knots becoming northwest 10 to 20 knots in the afternoon, then becoming north 15 to 25 knots late. A slight chance of rain showers through early afternoon. A slight chance of snow showers. Waves subsiding to 3 to 6 feet occasionally to 8 feet. .FRIDAY NIGHT...North winds 15 to 25 knots diminishing to 10 to 20 knots late. Freezing spray. Waves building to 5 to 8 feet occasionally to 10 feet, then subsiding to 3 to 6 feet occasionally to 8 feet. .SATURDAY...North winds 5 to 15 knots veering south by mid afternoon. Waves subsiding to calm to 2 feet. .SATURDAY NIGHT...Southeast winds 5 to 15 knots increasing to 10 to 20 knots after midnight. A chance of snow after midnight. Waves building to 2 to 4 feet. .SUNDAY...Southeast winds 20 to 30 knots backing east by mid afternoon. Snow likely. Waves building to 6 to 9 feet occasionally to 11 feet. .SUNDAY NIGHT...Northeast winds 15 to 25 knots backing north after midnight. Snow likely through midnight, then a chance of snow after midnight. Waves subsiding to 5 to 8 feet occasionally to 10 feet. .MONDAY...North winds 15 to 25 knots diminishing to 5 to 15 knots. Waves subsiding to 1 to 3 feet. .TUESDAY...Northwest winds 5 to 15 knots backing west. Waves subsiding to calm to 2 feet. $$ LSZ264-210345- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 334 PM EDT Thu Mar 20 2025 .LATE THIS AFTERNOON...Southwest winds 15 to 25 knots. Waves 2 to 4 feet building to 3 to 5 feet occasionally to 7 feet. .TONIGHT...Southwest winds 15 to 25 knots increasing to 20 to 30 knots after midnight. A slight chance of snow showers after midnight. Waves building to 5 to 8 feet occasionally to 10 feet. .FRIDAY...West winds 20 to 30 knots becoming north 15 to 25 knots in the afternoon, then increasing to 20 to 30 knots late. A slight chance of rain showers through early afternoon. A slight chance of snow showers. Freezing spray by mid afternoon. Waves subsiding to 3 to 6 feet occasionally to 8 feet, then building to 6 to 9 feet occasionally to 11 feet. .FRIDAY NIGHT...North winds 20 to 30 knots diminishing to 15 to 25 knots late. Heavy freezing spray. A slight chance of snow showers. Waves building to 7 to 10 feet occasionally to 13 feet, then subsiding to 4 to 7 feet occasionally to 9 feet. .SATURDAY...North winds 10 to 20 knots becoming west 5 to 15 knots by mid afternoon. A slight chance of snow showers through early afternoon. Waves subsiding to calm to 2 feet. .SATURDAY NIGHT...Southeast winds 5 to 15 knots increasing to 15 to 25 knots after midnight. Waves building to 3 to 5 feet occasionally to 7 feet. .SUNDAY...Southeast winds 20 to 30 knots. A chance of snow through early afternoon, then snow likely by mid afternoon. Waves building to 7 to 10 feet occasionally to 13 feet. .SUNDAY NIGHT...East winds 20 to 30 knots becoming northeast 15 to 25 knots after midnight. Snow likely through midnight, then a chance of snow after midnight. Waves subsiding to 5 to 8 feet occasionally to 10 feet. .MONDAY...North winds 15 to 25 knots diminishing to 5 to 15 knots. Waves subsiding to 1 to 3 feet. .TUESDAY...North winds 5 to 15 knots backing west. Waves subsiding to calm to 2 feet. $$ LSZ265-210345- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 334 PM EDT Thu Mar 20 2025 .LATE THIS AFTERNOON...West winds 10 to 20 knots. Waves 3 to 5 feet occasionally to 7 feet subsiding to 1 to 3 feet. .TONIGHT...Southwest winds 10 to 20 knots increasing to 20 to 30 knots. Waves subsiding to calm to 2 feet, then building to 2 to 4 feet. .FRIDAY...Southwest winds 20 to 30 knots becoming west 10 to 20 knots in the afternoon, then becoming north 20 to 30 knots late. A chance of snow showers, possibly mixed with rain. Waves subsiding to calm to 2 feet, then building to 4 to 7 feet occasionally to 9 feet. .FRIDAY NIGHT...North winds 20 to 30 knots diminishing to 15 to 25 knots late. Heavy freezing spray. A slight chance of snow showers. Waves building to 7 to 10 feet occasionally to 13 feet, then subsiding to 5 to 8 feet occasionally to 10 feet. .SATURDAY...Northwest winds 15 to 25 knots diminishing to 5 to 15 knots by mid afternoon. Heavy freezing spray through early afternoon. A slight chance of snow showers through early afternoon. Waves subsiding to calm to 2 feet. .SATURDAY NIGHT...Southeast winds 10 to 20 knots increasing to 15 to 25 knots after midnight. Waves building to 2 to 4 feet. .SUNDAY...Southeast winds 20 to 30 knots. A chance of snow through early afternoon, then snow likely by mid afternoon. Waves building to 3 to 6 feet occasionally to 8 feet. .SUNDAY NIGHT...East winds 20 to 30 knots becoming northeast 15 to 25 knots after midnight. Snow likely through midnight, then a chance of snow after midnight. Waves 3 to 6 feet occasionally to 8 feet. .MONDAY...North winds 15 to 25 knots diminishing to 10 to 20 knots. A chance of snow showers. Waves building to 4 to 7 feet occasionally to 9 feet, then subsiding to 2 to 4 feet. .TUESDAY...Northwest winds 10 to 20 knots backing west. Waves subsiding to calm to 2 feet. $$ LSZ266-210345- 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- 334 PM EDT Thu Mar 20 2025 .LATE THIS AFTERNOON...West winds 15 to 25 knots. Waves 3 to 6 feet occasionally to 8 feet. .TONIGHT...South winds 15 to 25 knots veering southwest after midnight, then increasing to 20 to 30 knots late. Waves building to 4 to 7 feet occasionally to 9 feet, then subsiding to 3 to 6 feet occasionally to 8 feet. .FRIDAY...Southwest winds 20 to 30 knots diminishing to 15 to 25 knots in the afternoon, then becoming north 20 to 30 knots late. A chance of snow showers, possibly mixed with rain. Waves building to 5 to 8 feet occasionally to 10 feet, then subsiding to 3 to 6 feet occasionally to 8 feet. .FRIDAY NIGHT...North winds to 30 knots with a few gale force gusts to 35 knots possible diminishing to 20 to 30 knots late. Heavy freezing spray. A chance of snow showers. Waves building to 8 to 11 feet occasionally to 14 feet, then subsiding to 6 to 9 feet occasionally to 11 feet. .SATURDAY...North winds 15 to 25 knots becoming northwest 5 to 15 knots by mid afternoon. Freezing spray through early afternoon. A chance of snow showers through early afternoon. Waves subsiding to 1 to 3 feet. .SATURDAY NIGHT...Southeast winds 5 to 15 knots becoming south 15 to 25 knots after midnight. Waves subsiding to calm to 2 feet, then building to 2 to 4 feet. .SUNDAY...Southeast winds 20 to 30 knots with a few gale gusts to 35 knots by mid afternoon. A chance of snow through early afternoon, then snow likely by mid afternoon. Waves building to 5 to 8 feet occasionally to 10 feet. .SUNDAY NIGHT...East wind 20 to 30 knots with a few gale gusts to 35 knots becoming northeast 15 to 25 knots after midnight. Snow likely through midnight, then a chance of snow after midnight. Waves subsiding to 4 to 7 feet occasionally to 9 feet. .MONDAY...North winds 20 to 30 knots diminishing to 10 to 20 knots. A chance of snow showers. Waves subsiding to 2 to 4 feet. .TUESDAY...Northwest winds 10 to 20 knots backing west. Waves subsiding to calm to 2 feet. $$ LSZ267-210345- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 334 PM EDT Thu Mar 20 2025 .LATE THIS AFTERNOON...Northwest winds 15 to 25 knots. Waves 3 to 6 feet occasionally to 8 feet. .TONIGHT...West winds 10 to 20 knots backing south after midnight, then becoming southwest 20 to 30 knots late. Waves subsiding to 1 to 3 feet, then building to 3 to 6 feet occasionally to 8 feet. .FRIDAY...Southwest winds to 30 knots with a few gale force gusts to 35 knots possible diminishing to 20 to 30 knots in the afternoon, then veering northwest late. A chance of snow showers, possibly mixed with rain. Waves building to 5 to 8 feet occasionally to 10 feet, then subsiding to 2 to 4 feet. .FRIDAY NIGHT...Northwest winds to 30 knots with a few gale force gusts to 35 knots possible veering north after midnight, then diminishing to 20 to 30 knots late. Heavy freezing spray. A slight chance of snow showers. Waves building to 7 to 10 feet occasionally to 13 feet, then subsiding to 5 to 8 feet occasionally to 10 feet. .SATURDAY...North winds 15 to 25 knots becoming northwest 10 to 20 knots by mid afternoon. Heavy freezing spray through early afternoon. A slight chance of snow showers through early afternoon. Waves subsiding to 1 to 3 feet. .SATURDAY NIGHT...South winds 10 to 20 knots backing southeast after midnight. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. .SUNDAY...Southeast winds 15 to 25 knots increasing to 30 knots with a few gale gusts to 35 knots by mid afternoon. A chance of snow. Waves building to 4 to 7 feet occasionally to 9 feet. .SUNDAY NIGHT...East winds 20 to 30 knots. Snow likely. Waves subsiding to 3 to 5 feet occasionally to 7 feet. .MONDAY...North winds 15 to 25 knots diminishing to 10 to 20 knots. A chance of snow showers. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to 2 to 4 feet. .TUESDAY...Northwest winds 10 to 20 knots. Waves subsiding to calm to 2 feet. $$ LSZ261-210345- MAFOR 2021/ Superior West 12530 13540 11640 11720 11730. Waves 2 to 7 feet. Superior North Central 12530 11540 11541 11540 11640 11740 11840. Waves 3 to 8 feet. Superior South Central 11620 13520 12540 11520 11730. A chance of snow and rain showers Friday afternoon. Waves 1 to 5 feet. Superior East 11630 11520 11430 11530 13540 11630. A chance of snow and rain showers Friday afternoon. Waves 3 to 8 feet. $$ 07 Experimental modernized open lake forecast is available online at weather.gov/mqt/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes