


Great Lakes Forecast
Issued by NWS
Issued by NWS
334 FZUS63 KMQT 171402 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 1002 AM EDT Tue Jun 17 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 29.6 inch low is currently moving NE into central Ontario this morning and will deepen to 29.4 inches as it travels into Quebec Wednesday morning. Meanwhile, a weak 29.8 inch ridge builds over the lake this afternoon into early Wednesday. By late Wednesday, a 29.6 inch low approaches Lake Michigan from the southwest while another 29.7 inch trough approaches Lake Superior from the northwest. These two features merge into a 29.5 inch low over Georgian Bay Wednesday night while a 30.0 inch high moves over northern Ontario. Weak 30.0 inch ridging then remains over Lake Superior until Friday. On Saturday, a shortwave around 29.6 inches is expected to move through the lake. LSZ162-172000- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 1002 AM EDT Tue Jun 17 2025 /902 AM CDT Tue Jun 17 2025/ .REST OF TODAY...West winds 10 to 20 knots backing southwest in the afternoon. Waves 1 to 3 feet. .TONIGHT...West winds 5 to 15 knots. Waves subsiding to calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots backing south late. Waves calm to 2 feet. .WEDNESDAY NIGHT...Southwest winds 5 to 15 knots veering west after midnight. A chance of showers. A slight chance of thunderstorms after midnight. Waves calm to 2 feet. .THURSDAY...East winds 10 to 20 knots backing northeast by mid afternoon. A chance of showers through early afternoon. A slight chance of thunderstorms. Showers likely by mid afternoon. Waves calm to 2 feet. .THURSDAY NIGHT...Northeast winds 5 to 15 knots. A chance of showers. Waves calm to 2 feet. .FRIDAY...Northeast winds 10 to 20 knots. A chance of showers, then showers likely and a chance of thunderstorms. Waves calm to 2 feet. .SATURDAY...Northeast winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. $$ LSZ263-172000- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 1002 AM EDT Tue Jun 17 2025 .REST OF TODAY...West winds 10 to 20 knots backing southwest in the afternoon. Waves 2 to 4 feet subsiding to 1 to 3 feet. .TONIGHT...Southwest winds 5 to 15 knots veering west after midnight. Waves subsiding to calm to 2 feet. .WEDNESDAY...West winds less than 10 knots becoming southwest 5 to 15 knots in the afternoon, then backing south late. Waves calm to 2 feet. .WEDNESDAY NIGHT...Southwest winds 5 to 15 knots veering west after midnight. A slight chance of showers. A slight chance of thunderstorms after midnight. Waves calm to 2 feet. .THURSDAY...North winds 5 to 15 knots veering northeast by mid afternoon. A chance of showers through early afternoon. A slight chance of thunderstorms. Showers likely by mid afternoon. Waves calm to 2 feet. .THURSDAY NIGHT...Northeast winds 5 to 15 knots veering east after midnight. A chance of showers. Waves calm to 2 feet. .FRIDAY...East winds 5 to 15 knots. A chance of showers, then showers likely and a chance of thunderstorms. Waves calm to 2 feet. .SATURDAY...Northeast winds 5 to 15 knots veering east. A chance of showers. Waves calm to 2 feet. $$ LSZ264-172000- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 1002 AM EDT Tue Jun 17 2025 .REST OF TODAY...West winds 15 to 25 knots becoming southwest 10 to 20 knots late. Waves 3 to 6 feet occasionally to 8 feet subsiding to 1 to 3 feet. .TONIGHT...Southwest winds 5 to 15 knots veering west after midnight. Waves subsiding to calm to 2 feet. .WEDNESDAY...West winds less than 10 knots becoming south 5 to 15 knots in the afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...South winds 5 to 15 knots veering west after midnight. A slight chance of showers after midnight. Waves calm to 2 feet. .THURSDAY...North winds 5 to 15 knots. A chance of showers. Waves calm to 2 feet. .THURSDAY NIGHT...North winds 5 to 15 knots veering northeast after midnight. Waves calm to 2 feet. .FRIDAY...East winds 5 to 15 knots veering southeast. A chance of showers. Waves calm to 2 feet. .SATURDAY...East winds 5 to 15 knots veering southeast. A chance of showers. Waves calm to 2 feet. $$ LSZ265-172000- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 1002 AM EDT Tue Jun 17 2025 .REST OF TODAY...West winds 20 to 30 knots diminishing to 10 to 20 knots. Waves 2 to 4 feet subsiding to calm to 2 feet. .TONIGHT...Southwest winds 5 to 15 knots veering west late. Waves calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots backing east in the afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...Southeast winds 5 to 15 knots veering west after midnight. A slight chance of showers through midnight. Waves calm to 2 feet. .THURSDAY...Northwest winds 10 to 20 knots veering north by mid afternoon. A chance of showers. Waves calm to 2 feet. .THURSDAY NIGHT...Northwest winds 5 to 15 knots veering north after midnight. A chance of showers. Waves calm to 2 feet. .FRIDAY...East winds 10 to 20 knots veering southeast. A chance of showers, then showers likely and a chance of thunderstorms. Waves calm to 2 feet. .SATURDAY...East winds 10 to 20 knots veering southeast. A chance of showers. Waves calm to 2 feet. $$ LSZ266-172000- 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- 1002 AM EDT Tue Jun 17 2025 .REST OF TODAY...West winds 15 to 25 knots diminishing to 10 to 20 knots late. Patchy fog. Waves 3 to 6 feet occasionally to 8 feet building to 4 to 7 feet occasionally to 9 feet, then subsiding to 2 to 4 feet. .TONIGHT...Southwest winds 5 to 15 knots backing south after midnight, then veering southwest late. Waves subsiding to calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots veering northeast in the afternoon, then veering east late. A slight chance of showers by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...East winds 5 to 15 knots backing northwest after midnight. A chance of showers. Waves calm to 2 feet. .THURSDAY...Northwest winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .THURSDAY NIGHT...Northwest winds 5 to 15 knots veering north after midnight. A chance of showers. Waves calm to 2 feet. .FRIDAY...East winds 5 to 15 knots becoming southeast 10 to 20 knots. A chance of showers, then showers likely and a chance of thunderstorms. Waves building to 1 to 3 feet. .SATURDAY...East winds 10 to 20 knots veering southeast. A chance of showers and thunderstorms. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. $$ LSZ267-172000- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 1002 AM EDT Tue Jun 17 2025 .REST OF TODAY...Southwest winds 20 to 30 knots veering west in the afternoon, then diminishing to 10 to 20 knots late. A slight chance of showers by late morning. Patchy fog. Waves 3 to 5 feet occasionally to 7 feet subsiding to 2 to 4 feet, then building to 3 to 5 feet occasionally to 7 feet. .TONIGHT...West winds 5 to 15 knots backing south after midnight. Waves subsiding to calm to 2 feet. .WEDNESDAY...South winds 5 to 15 knots backing north in the afternoon, then veering northeast late. A slight chance of showers by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...North winds 5 to 15 knots becoming northwest 10 to 20 knots after midnight. A chance of showers. Waves calm to 2 feet. .THURSDAY...Northwest winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .THURSDAY NIGHT...Northwest winds 10 to 20 knots becoming north 5 to 15 knots after midnight. A chance of showers. Waves calm to 2 feet. .FRIDAY...North winds 10 to 20 knots veering southeast. A chance of showers, then showers likely. Waves calm to 2 feet. .SATURDAY...Southeast winds 10 to 20 knots. A chance of showers and thunderstorms. Waves building to 1 to 3 feet. $$ LSZ261-172000- MAFOR 1715/ Superior West 11620 12520 11510 12610 12600. Waves 1 to 3 feet this afternoon and tonight. Waves 1 foot or less Wednesday morning. Superior North Central 12630 11620 12510 12610 11600. Waves 3 to 6 feet subsiding to 2 to 4 feet this afternoon. Waves 2 to 4 feet tonight. Waves 1 to 2 feet Wednesday morning. Superior South Central 11630 11620 11610 11500 11510 11500 12600. Waves 3 to 5 feet subsiding to 2 to 3 feet this afternoon. Waves 2 feet or less tonight and Wednesday morning. Superior East 11640 11630 11620 11610 13400 11500. Waves 3 to 6 feet this afternoon. Waves 3 to 5 feet subsiding to 1 to 3 feet tonight. Waves 1 to 2 feet Wednesday morning. $$ 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