


Great Lakes Forecast
Issued by NWS
Issued by NWS
062 FZUS63 KMQT 132001 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 401 PM EDT Wed Aug 13 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 30.1 inch high pressure over Ontario will continue to build southeast to Lake Superior tonight into early Thursday. A transition to weak troughing of 29.9 inches is expected Thursday night into Friday as high pressure pushes east from Ontario into Quebec and a low pressure moves from northern Manitoba and Ontario to the Hudson Bay. Another high pressure digging across the Canadian Prairies into northern Ontario on Saturday brings 30.1 inch ridging over Lake Superior for the weekend. LSZ162-140800- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 401 PM EDT Wed Aug 13 2025 /301 PM CDT Wed Aug 13 2025/ .LATE THIS AFTERNOON...Southeast winds 5 to 15 knots. Waves calm to 2 feet. .TONIGHT...East winds 5 to 15 knots increasing to 10 to 20 knots after midnight. Waves calm to 2 feet. .THURSDAY...East winds 10 to 20 knots. A slight chance of showers by mid afternoon. Waves building to 1 to 3 feet. .THURSDAY NIGHT...East winds 10 to 20 knots veering south after midnight. A chance of showers and thunderstorms. Waves 1 to 3 feet. .FRIDAY...Southwest winds 10 to 20 knots. A slight chance of showers. A slight chance of thunderstorms by mid afternoon. Waves subsiding to calm to 2 feet. .FRIDAY NIGHT...Southwest winds 5 to 15 knots veering north after midnight. A chance of showers and thunderstorms. Waves calm to 2 feet. .SATURDAY...Northeast winds 10 to 20 knots veering east by mid afternoon. A chance of showers through early afternoon. Waves calm to 2 feet. .SATURDAY NIGHT...Northeast winds 10 to 20 knots increasing to 15 to 25 knots after midnight. Waves building to 2 to 4 feet. .SUNDAY...East winds 15 to 25 knots. A chance of showers. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to 2 to 4 feet. .MONDAY...East winds 10 to 20 knots backing northeast. A chance of showers. Waves subsiding to 1 to 3 feet. $$ LSZ263-140800- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 401 PM EDT Wed Aug 13 2025 .LATE THIS AFTERNOON...East winds 5 to 15 knots. Waves calm to 2 feet. .TONIGHT...East winds 5 to 15 knots. Waves calm to 2 feet. .THURSDAY...Southeast winds 5 to 15 knots backing east in the afternoon, then increasing to 10 to 20 knots late. Waves building to 1 to 3 feet. .THURSDAY NIGHT...Southeast winds 10 to 20 knots veering south after midnight. A slight chance of showers and thunderstorms after midnight. Waves building to 2 to 4 feet. .FRIDAY...Southwest winds 10 to 20 knots. A slight chance of showers. A slight chance of thunderstorms by mid afternoon. Waves subsiding to 1 to 3 feet. .FRIDAY NIGHT...Southwest winds 5 to 15 knots veering west after midnight. A chance of showers and thunderstorms. Waves subsiding to calm to 2 feet. .SATURDAY...North winds 5 to 15 knots veering northeast by mid afternoon. A chance of showers. Waves calm to 2 feet. .SATURDAY NIGHT...Northeast winds 5 to 15 knots increasing to 15 to 25 knots after midnight. Waves building to 2 to 4 feet. .SUNDAY...East winds 15 to 25 knots. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to 1 to 3 feet. .MONDAY...East winds 10 to 20 knots. Waves 1 to 3 feet. $$ LSZ264-140800- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 401 PM EDT Wed Aug 13 2025 .LATE THIS AFTERNOON...North winds 5 to 15 knots. Waves calm to 2 feet. .TONIGHT...North winds 5 to 15 knots veering east late. Waves calm to 2 feet. .THURSDAY...East winds 5 to 15 knots veering southeast in the afternoon, then increasing to 10 to 20 knots late. Waves building to 1 to 3 feet. .THURSDAY NIGHT...Southeast winds 10 to 20 knots veering south after midnight. Waves building to 2 to 4 feet. .FRIDAY...South winds 10 to 20 knots becoming southwest 5 to 15 knots by mid afternoon. A slight chance of showers. A slight chance of thunderstorms by mid afternoon. Waves subsiding to 1 to 3 feet. .FRIDAY NIGHT...Southwest winds 5 to 15 knots veering west after midnight. A chance of showers. Waves subsiding to calm to 2 feet. .SATURDAY...North winds 5 to 15 knots. A chance of showers. Waves calm to 2 feet. .SATURDAY NIGHT...North winds 5 to 15 knots becoming northeast 10 to 20 knots after midnight. Waves building to 1 to 3 feet. .SUNDAY...East 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. .MONDAY...East winds 10 to 20 knots. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. $$ LSZ265-140800- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 401 PM EDT Wed Aug 13 2025 .LATE THIS AFTERNOON...North winds 10 to 20 knots. Waves calm to 2 feet. .TONIGHT...North winds 10 to 20 knots becoming northeast 5 to 15 knots late. Waves calm to 2 feet. .THURSDAY...East winds 5 to 15 knots increasing to 15 to 25 knots. Waves calm to 2 feet. .THURSDAY NIGHT...Southeast winds 10 to 20 knots becoming south 15 to 25 knots after midnight. Waves calm to 2 feet. .FRIDAY...South winds 10 to 20 knots. Waves calm to 2 feet. .FRIDAY NIGHT...Southwest winds 10 to 20 knots veering west after midnight. A chance of showers. Waves calm to 2 feet. .SATURDAY...North winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .SATURDAY NIGHT...North winds 10 to 20 knots veering northeast after midnight. Waves building to 1 to 3 feet. .SUNDAY...Northeast winds 15 to 25 knots becoming east 10 to 20 knots. Waves subsiding to calm to 2 feet. .MONDAY...East winds 10 to 20 knots. A chance of showers. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. $$ LSZ266-140800- 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 Wed Aug 13 2025 .LATE THIS AFTERNOON...North winds 10 to 20 knots. Haze. Waves 1 to 3 feet. .TONIGHT...North winds 10 to 20 knots becoming northeast 5 to 15 knots late. Waves subsiding to calm to 2 feet. .THURSDAY...East winds 5 to 15 knots increasing to 10 to 20 knots late. Waves calm to 2 feet. .THURSDAY NIGHT...Southeast winds 10 to 20 knots becoming south 15 to 25 knots after midnight. Waves building to 2 to 4 feet. .FRIDAY...South winds 15 to 25 knots diminishing to 10 to 20 knots by mid afternoon. A slight chance of showers and thunderstorms by mid afternoon. Waves subsiding to 1 to 3 feet. .FRIDAY NIGHT...South winds 10 to 20 knots veering southwest after midnight. A chance of showers. Waves subsiding to calm to 2 feet. .SATURDAY...Northwest winds 10 to 20 knots veering north by mid afternoon. A chance of showers. Waves calm to 2 feet. .SATURDAY NIGHT...North winds 10 to 20 knots veering northeast after midnight. Waves building to 2 to 4 feet. .SUNDAY...Northeast winds 10 to 20 knots veering east. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. .MONDAY...East winds 10 to 20 knots. Waves subsiding to calm to 2 feet. $$ LSZ267-140800- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 401 PM EDT Wed Aug 13 2025 .LATE THIS AFTERNOON...Northwest winds 10 to 20 knots. Haze. Waves 1 to 3 feet subsiding to calm to 2 feet. .TONIGHT...Northwest winds 10 to 20 knots veering northeast late. Haze through midnight. Waves calm to 2 feet. .THURSDAY...East winds 10 to 20 knots diminishing to 5 to 15 knots in the afternoon. Waves calm to 2 feet. .THURSDAY NIGHT...Southeast winds 5 to 15 knots becoming south 10 to 20 knots after midnight. Waves calm to 2 feet. .FRIDAY...South winds 10 to 20 knots. Waves building to 1 to 3 feet. .FRIDAY NIGHT...South winds 15 to 25 knots becoming southwest 10 to 20 knots after midnight. A chance of showers and thunderstorms. Waves subsiding to calm to 2 feet. .SATURDAY...West winds 10 to 20 knots veering northwest by mid afternoon. A chance of showers and thunderstorms. Waves calm to 2 feet. .SATURDAY NIGHT...Northwest winds 10 to 20 knots becoming northeast 15 to 25 knots after midnight. Waves building to 2 to 4 feet. .SUNDAY...Northeast winds 10 to 20 knots veering east. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. .MONDAY...Southeast winds 10 to 20 knots backing east. A chance of showers. Waves subsiding to calm to 2 feet. $$ LSZ261-140200- MAFOR 1321/ Superior West 11300 11200 12210 13310 11210. Waves 2 feet or less. Superior North Central 12800 11810 11100 12200 11310 11320. Waves 1 to 2 feet. Superior South Central 13810 12100 11200 11210 11220. Waves 1 to 3 feet. Superior East 12710 11810 12110 12210 11200. Waves 1 to 3 feet. $$ 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