FZUS63 KMQT 220201 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 1000 PM EDT Fri Aug 21 2026 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 29.9 inch trough will linger over Lake Superior through Saturday morning. This is followed by 30.1 inch ridging for the latter part of the weekend into early next week via a 30.2 inch parent high from the Canadian Prairies that drops down into the Ohio River Valley by late Monday, weakening to 30.1 inches as it does so. A 29.7 inch low over the Canadian Prairies Monday night then drops southeast towards Lake Superior, arriving early Wednesday morning. The low shifts east Wendesday night with weak ridging of 29.9 inches building over the lake on Thursday. LSZ162-220800- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 1000 PM EDT Fri Aug 21 2026 /900 PM CDT Fri Aug 21 2026/ .REST OF TONIGHT...West winds 5 to 15 knots becoming northwest 10 to 20 knots late. A slight chance of thunderstorms by midnight. A slight chance of showers. Waves calm to 2 feet. .SATURDAY...Northwest winds 10 to 20 knots backing west late. Waves calm to 2 feet. .SATURDAY NIGHT...North winds 10 to 20 knots. Waves calm to 2 feet. .SUNDAY...North winds 5 to 15 knots veering south by mid afternoon. Waves calm to 2 feet. .SUNDAY NIGHT...South winds 5 to 15 knots becoming north less than 10 knots after midnight. Waves calm to 2 feet. .MONDAY...North winds less than 10 knots becoming south 5 to 15 knots by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...East winds 5 to 15 knots becoming south less than 10 knots after midnight. Waves calm to 2 feet. .TUESDAY...South winds 5 to 15 knots veering west. A chance of showers and thunderstorms. Waves calm to 2 feet. .WEDNESDAY...West winds 10 to 20 knots becoming northwest 5 to 15 knots. Waves calm to 2 feet. $$ LSZ263-220800- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 1000 PM EDT Fri Aug 21 2026 .REST OF TONIGHT...Southwest winds 5 to 15 knots veering west after midnight, then becoming northwest 10 to 20 knots late. A slight chance of showers and thunderstorms after midnight. Waves calm to 2 feet. .SATURDAY...Northwest winds 10 to 20 knots diminishing to 5 to 15 knots late. Waves calm to 2 feet. .SATURDAY NIGHT...North winds 10 to 20 knots. Waves building to 1 to 3 feet. .SUNDAY...North winds 10 to 20 knots becoming west 5 to 15 knots by mid afternoon. Waves building to 2 to 4 feet, then subsiding to calm to 2 feet. .SUNDAY NIGHT...West winds 5 to 15 knots veering northwest after midnight. Waves calm to 2 feet. .MONDAY...Northwest winds less than 10 knots becoming southwest 5 to 15 knots by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...South winds 5 to 15 knots. Waves calm to 2 feet. .TUESDAY...South winds 5 to 15 knots becoming west 10 to 20 knots. A chance of showers. A chance of thunderstorms. Showers likely. Waves calm to 2 feet. .WEDNESDAY...West winds 10 to 20 knots becoming northwest 5 to 15 knots. Waves calm to 2 feet. $$ LSZ264-220800- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 1000 PM EDT Fri Aug 21 2026 .REST OF TONIGHT...West winds 5 to 15 knots veering northwest late. A slight chance of showers after midnight. Waves calm to 2 feet. .SATURDAY...Northwest winds 5 to 15 knots increasing to 10 to 20 knots in the afternoon. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .SATURDAY NIGHT...North winds 10 to 20 knots increasing to 15 to 25 knots late. Waves building to 2 to 4 feet. .SUNDAY...North winds 15 to 25 knots becoming northwest 10 to 20 knots by mid afternoon. Waves subsiding to calm to 2 feet. .SUNDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to 2 feet. .MONDAY...Northwest winds less than 10 knots becoming west 5 to 15 knots by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to 2 feet. .TUESDAY...South winds 5 to 15 knots veering southwest. Showers likely. Waves calm to 2 feet. .WEDNESDAY...West winds 10 to 20 knots becoming northwest 5 to 15 knots. A chance of showers. Waves calm to 2 feet. $$ LSZ265-220800- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 1000 PM EDT Fri Aug 21 2026 .REST OF TONIGHT...West winds 10 to 20 knots increasing to 15 to 25 knots late. A slight chance of showers after midnight. Waves calm to 2 feet. .SATURDAY...Northwest winds 15 to 25 knots increasing to 20 to 30 knots in the afternoon. A slight chance of showers through early afternoon. Waves building to 3 to 6 feet occasionally to 8 feet. .SATURDAY NIGHT...Northwest winds 20 to 30 knots veering north after midnight. Waves subsiding to 3 to 6 feet occasionally to 8 feet. .SUNDAY...North winds 20 to 30 knots. Waves building to 4 to 7 feet occasionally to 9 feet, then subsiding to 3 to 5 feet occasionally to 7 feet. .SUNDAY NIGHT...Northwest winds 15 to 25 knots diminishing to 10 to 20 knots after midnight. Waves subsiding to calm to 2 feet. .MONDAY...Northwest winds 10 to 20 knots diminishing to 5 to 15 knots by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to 2 feet. .TUESDAY...Southeast winds 5 to 15 knots becoming southwest 15 to 25 knots. A chance of showers, then showers likely. Waves calm to 2 feet. .WEDNESDAY...West winds 15 to 25 knots becoming northwest 10 to 20 knots. A chance of showers. Waves calm to 2 feet. $$ LSZ266-220800- 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- 1000 PM EDT Fri Aug 21 2026 .REST OF TONIGHT...Northwest winds 10 to 20 knots. Waves calm to 2 feet. .SATURDAY...Northwest winds 15 to 25 knots increasing to 20 to 30 knots in the afternoon. Waves building to 4 to 7 feet occasionally to 9 feet. .SATURDAY NIGHT...Northwest winds 20 to 30 knots veering north after midnight. Waves subsiding to 3 to 6 feet occasionally to 8 feet, then building to 4 to 7 feet occasionally to 9 feet. .SUNDAY...North winds 20 to 30 knots backing northwest by mid afternoon. Waves building to 5 to 8 feet occasionally to 10 feet, then subsiding to 3 to 6 feet occasionally to 8 feet. .SUNDAY NIGHT...Northwest winds 15 to 25 knots diminishing to 10 to 20 knots after midnight. Waves subsiding to 1 to 3 feet. .MONDAY...Northwest winds 5 to 15 knots. Waves subsiding to calm to 2 feet. .MONDAY NIGHT...West winds 5 to 15 knots backing southwest after midnight. Waves calm to 2 feet. .TUESDAY...South winds 10 to 20 knots increasing to 15 to 25 knots. Showers likely. Waves building to 1 to 3 feet. .WEDNESDAY...West winds 10 to 20 knots veering northwest. A chance of showers. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. $$ LSZ267-220800- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 1000 PM EDT Fri Aug 21 2026 .REST OF TONIGHT...South winds 10 to 20 knots veering northwest after midnight. A slight chance of showers and thunderstorms by midnight. Waves calm to 2 feet. .SATURDAY...Northwest winds 10 to 20 knots increasing to 20 to 30 knots. Waves building to 3 to 5 feet occasionally to 7 feet. .SATURDAY NIGHT...Northwest winds 20 to 30 knots veering north after midnight. Waves building to 3 to 6 feet occasionally to 8 feet. .SUNDAY...North winds 20 to 30 knots backing northwest by mid afternoon. Waves building to 4 to 8 feet occasionally to 10 feet. .SUNDAY NIGHT...Northwest winds 15 to 25 knots. Waves subsiding to 2 to 4 feet. .MONDAY...Northwest winds 10 to 20 knots. Waves subsiding to 1 to 3 feet. .MONDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to calm to 2 feet. .TUESDAY...Southeast winds 5 to 15 knots becoming south 10 to 20 knots. A chance of showers. Waves building to 1 to 3 feet. .WEDNESDAY...South winds 10 to 20 knots veering northwest. A chance of showers. Waves subsiding to calm to 2 feet. $$ LSZ261-220800- MAFOR 2203/ Superior West 11600 11710 12720 12710 11610 11710. Waves 2 feet or less. Superior North Central 12610 11710 12720 11730 12720. Waves 1 to 3 feet. Superior South Central 13720 11730 14740. Waves 1 to 2 feet overnight. Waves 1 to 2 feet building to 3 to 5 feet Saturday. Waves 3 to 5 feet Saturday evening. Superior East 11700 14710 11730 12740. Waves around 1 foot overnight. Waves 1 to 2 feet building to 2 to 4 feet Saturday. Waves 3 to 5 feet Saturday evening. $$ 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