


Great Lakes Forecast
Issued by NWS
Issued by NWS
539 FZUS63 KMQT 052001 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 401 PM EDT Sun Oct 5 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 29.4 inch low over far northern Minnesota and southern Ontario will move to James Bay by late tonight, reaching far northern Quebec as it deepens to 29.2 inches by Monday morning. This results in 29.7 inch troughing over Lake Superior through tonight. In its wake, a 30.3 inch high pressure moving across the Northern Plains builds 30.1 inch ridging back over Lake Superior Monday through Tuesday. The ridge strengthens to 30.4 inches over the lake on Wednesday as reinforcing high pressure moves overhead from the Canadian Prairies. The high shifts east to New England by Thursday night, allowing 29.8 inch troughing to return to the lake as a 29.2 inch low moves over Hudson Bay Friday morning. LSZ162-060800- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 401 PM EDT Sun Oct 5 2025 /301 PM CDT Sun Oct 5 2025/ ...GALE WARNING IN EFFECT THROUGH LATE TONIGHT... .LATE THIS AFTERNOON...South gales to 40 knots. A chance of showers. Waves 5 to 9 feet occasionally to 11 feet. .TONIGHT...South gales to 40 knots becoming northwest gales to 45 knots after midnight, then diminishing to 20 to 30 knots late. Waves building to 7 to 10 feet occasionally to 13 feet, then subsiding to 1 to 3 feet. .MONDAY...Northwest winds 10 to 20 knots backing southwest late. Waves subsiding to calm to 2 feet. .MONDAY NIGHT...West winds 10 to 20 knots increasing to 15 to 25 knots late. Waves building to 1 to 3 feet. .TUESDAY...West winds 15 to 25 knots becoming northwest 10 to 20 knots by mid afternoon. Waves building to 2 to 4 feet, then subsiding to calm to 2 feet. .TUESDAY NIGHT...North winds 5 to 15 knots. Waves calm to 2 feet. .WEDNESDAY...Southeast winds 5 to 15 knots. Waves calm to 2 feet. .WEDNESDAY NIGHT...Southeast winds 10 to 20 knots veering south after midnight. Waves building to 1 to 3 feet. .THURSDAY...Southwest winds 15 to 25 knots diminishing to 10 to 20 knots. Waves building to 2 to 4 feet, then subsiding to calm to 2 feet. .FRIDAY...West winds 10 to 20 knots becoming southwest 5 to 15 knots. Waves calm to 2 feet. $$ LSZ263-060800- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 401 PM EDT Sun Oct 5 2025 ...GALE WARNING IN EFFECT THROUGH LATE TONIGHT... .LATE THIS AFTERNOON...South gales to 40 knots. A slight chance of showers. Waves 5 to 9 feet occasionally to 11 feet. .TONIGHT...South gales to 40 knots becoming northwest gales to 35 knots after midnight, then diminishing to 20 to 30 knots late. A slight chance of showers through midnight. Waves building to 7 to 10 feet occasionally to 13 feet, then subsiding to 3 to 6 feet occasionally to 8 feet. .MONDAY...Northwest winds 10 to 20 knots backing southwest late. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. .MONDAY NIGHT...West winds 10 to 20 knots increasing to 15 to 25 knots after midnight. Waves building to 3 to 5 feet occasionally to 7 feet. .TUESDAY...West winds 15 to 25 knots veering northwest by mid afternoon. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to 1 to 3 feet. .TUESDAY NIGHT...North winds 5 to 15 knots. Waves subsiding to calm to 2 feet. .WEDNESDAY...South winds 5 to 15 knots. Waves calm to 2 feet. .WEDNESDAY NIGHT...South winds 5 to 15 knots increasing to 15 to 25 knots after midnight. Waves building to 2 to 4 feet. .THURSDAY...Southwest winds 20 to 30 knots diminishing to 15 to 25 knots. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet. .FRIDAY...West winds 10 to 20 knots becoming southwest 5 to 15 knots. Waves subsiding to calm to 2 feet. $$ LSZ264-060800- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 401 PM EDT Sun Oct 5 2025 ...GALE WARNING IN EFFECT UNTIL 2 AM EDT MONDAY... .LATE THIS AFTERNOON...South gales to 35 knots. A slight chance of showers. Waves 5 to 8 feet occasionally to 10 feet. .TONIGHT...South gales to 35 knots veering west after midnight, then becoming northwest 20 to 30 knots late. A slight chance of showers through midnight. Waves building to 6 to 9 feet occasionally to 11 feet, then subsiding to 4 to 7 feet occasionally to 9 feet. .MONDAY...Northwest winds 15 to 25 knots becoming west 10 to 20 knots in the afternoon, then backing southwest late. Waves subsiding to calm to 2 feet. .MONDAY NIGHT...West winds 10 to 20 knots increasing to 15 to 25 knots after midnight. Waves building to 3 to 5 feet occasionally to 7 feet. .TUESDAY...West winds 15 to 25 knots veering northwest by mid afternoon. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to 2 to 4 feet. .TUESDAY NIGHT...North winds 5 to 15 knots. Waves subsiding to calm to 2 feet. .WEDNESDAY...Southwest winds 5 to 15 knots backing south by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots after midnight. Waves building to 1 to 3 feet. .THURSDAY...Southwest winds 15 to 25 knots. Waves building to 2 to 4 feet. .FRIDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots. Waves subsiding to calm to 2 feet. $$ LSZ265-060800- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 401 PM EDT Sun Oct 5 2025 ...GALE WARNING IN EFFECT UNTIL 2 AM EDT MONDAY... .LATE THIS AFTERNOON...Southeast gales to 35 knots. Waves 3 to 6 feet occasionally to 8 feet. .TONIGHT...South gales to 40 knots becoming west gales to 35 knots after midnight, then veering northwest late. A slight chance of thunderstorms through midnight. A chance of showers. Waves building to 4 to 7 feet occasionally to 9 feet, then subsiding to 3 to 5 feet occasionally to 7 feet. .MONDAY...Northwest winds 20 to 30 knots diminishing to 10 to 20 knots in the afternoon, then backing west late. Waves subsiding to calm to 2 feet. .MONDAY NIGHT...West winds 5 to 15 knots increasing to 15 to 25 knots. Waves calm to 2 feet. .TUESDAY...West winds 15 to 25 knots becoming northwest 20 to 30 knots by mid afternoon. Waves building to 1 to 3 feet. .TUESDAY NIGHT...North winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to calm to 2 feet. .WEDNESDAY...North winds 5 to 15 knots becoming southeast 10 to 20 knots by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...Southeast winds 10 to 20 knots becoming south 15 to 25 knots after midnight. Waves calm to 2 feet. .THURSDAY...South winds 15 to 25 knots veering southwest. A chance of showers. Waves calm to 2 feet. .FRIDAY...West winds 10 to 20 knots. Waves calm to 2 feet. $$ LSZ266-060800- 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- 401 PM EDT Sun Oct 5 2025 ...GALE WARNING IN EFFECT UNTIL 2 AM EDT MONDAY... .LATE THIS AFTERNOON...South gales to 40 knots. Waves 5 to 9 feet occasionally to 11 feet. .TONIGHT...South gales to 40 knots becoming west gales to 35 knots after midnight, then becoming northwest 20 to 30 knots late. A chance of showers and a slight chance of thunderstorms. Waves building to 7 to 10 feet occasionally to 13 feet, then subsiding to 5 to 8 feet occasionally to 10 feet. .MONDAY...Northwest winds 20 to 30 knots diminishing to 5 to 15 knots. A slight chance of showers through early afternoon. Waves subsiding to 1 to 3 feet. .MONDAY NIGHT...West winds 5 to 15 knots increasing to 10 to 20 knots after midnight. A slight chance of showers through midnight. Waves building to 3 to 5 feet occasionally to 7 feet. .TUESDAY...West winds 15 to 25 knots veering northwest by mid afternoon. Waves building to 4 to 7 feet occasionally to 9 feet, then subsiding to 3 to 6 feet occasionally to 8 feet. .TUESDAY NIGHT...North winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to 1 to 3 feet. .WEDNESDAY...North winds 5 to 15 knots veering south by mid afternoon. Waves subsiding to calm to 2 feet. .WEDNESDAY NIGHT...South winds 10 to 20 knots. Waves building to 1 to 3 feet. .THURSDAY...South winds 15 to 25 knots veering southwest. A chance of showers. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet. .FRIDAY...West winds 10 to 20 knots. Waves subsiding to calm to 2 feet. $$ LSZ267-060800- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 401 PM EDT Sun Oct 5 2025 .LATE THIS AFTERNOON...Southeast winds to 30 knots with a few gale force gusts to 35 knots possible. Waves 4 to 8 feet occasionally to 10 feet. .TONIGHT...South winds to 30 knots with a few gale force gusts to 35 knots possible veering southwest after midnight, then becoming west 20 to 30 knots late. A chance of showers through midnight. A slight chance of thunderstorms. Showers after midnight. Waves subsiding to 4 to 7 feet occasionally to 9 feet. .MONDAY...Northwest winds 20 to 30 knots diminishing to 10 to 20 knots. A chance of showers through early afternoon. Waves subsiding to 2 to 4 feet. .MONDAY NIGHT...West winds 10 to 20 knots. A chance of showers through midnight. Waves subsiding to calm to 2 feet, then building to 2 to 4 feet. .TUESDAY...West winds 15 to 25 knots becoming northwest 20 to 30 knots by mid afternoon. Waves building to 4 to 7 feet occasionally to 9 feet. .TUESDAY NIGHT...North winds 15 to 25 knots diminishing to 10 to 20 knots after midnight. Waves subsiding to 1 to 3 feet. .WEDNESDAY...North winds 10 to 20 knots diminishing to 5 to 15 knots by mid afternoon. Waves subsiding to calm to 2 feet. .WEDNESDAY NIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots after midnight. Waves building to 1 to 3 feet. .THURSDAY...South winds 15 to 25 knots veering southwest. A chance of showers. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet. .FRIDAY...West winds 15 to 25 knots diminishing to 10 to 20 knots. A chance of showers. Waves subsiding to calm to 2 feet. $$ LSZ261-060200- MAFOR 0521/ Superior West...GALE WARNING IN EFFECT...11450 11550 11650 11740 11730 11720 12610. A chance of showers early this evening. Waves 5 to 8 feet subsiding to 3 to 6 feet tonight. Waves 3 to 5 feet subsiding to 1 to 3 feet Monday. Superior North Central...GALE WARNING IN EFFECT...12450 11550 11750 11740 11730 11720 11620. Waves 5 to 9 feet tonight. Waves 5 to 8 feet subsiding to 1 to 3 feet Monday. Superior South Central...GALE WARNING IN EFFECT...11350 11450 11550 11640 11740 11730 12720. A chance of showers tonight. Waves 3 to 6 feet building to 4 to 7 feet tonight. Waves 3 to 6 feet subsiding to 2 to 4 feet Monday. Superior East...GALE WARNING IN EFFECT...13450 11546 11740 12730 11720. Waves 5 to 9 feet building to 6 to 10 feet, then subsiding to 4 to 7 feet tonight. Waves 5 to 7 feet subsiding to 3 to 5 feet Monday. $$ 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