Great Lakes Forecast
Issued by NWS
Issued by NWS
520 FZUS63 KMQT 200743 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 343 AM EDT Fri Sep 20 2024 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...As a 29.3 inch low continues to track northeast to Hudson Bay today, the associated trough will fill to 29.7 inches as it moves over western Lake Superior. This trough will then dissipate, allowing weak 29.9 inch ridging to anchor over the Upper Great Lakes on Saturday morning. A new low pressure of 29.6 inches over southern Manitoba Saturday morning will then track across far northern Ontario Saturday afternoon and night. Its associated 29.9 inch trough will sweep across Lake Superior during Saturday night and Sunday morning. In its wake, 30.1 inch high pressure will build from the Northern Plains into northern Ontario during Sunday and Monday. Also on Monday, a 29.7 inch low pressure will track northeast to southern Wisconsin. 30.0 inch high pressure builds over the Lower MS Valley Tuesday. LSZ162-201545- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 343 AM EDT Fri Sep 20 2024 /243 AM CDT Fri Sep 20 2024/ .EARLY THIS MORNING...Southwest winds 10 to 20 knots. Waves calm to 2 feet. .TODAY...Southwest winds 10 to 20 knots increasing to 15 to 25 knots in the afternoon, then diminishing to 10 to 20 knots late. Waves building to 1 to 3 feet. .TONIGHT...West winds 5 to 15 knots backing southwest late. Waves subsiding to calm to 2 feet. .SATURDAY...East winds 5 to 15 knots backing northeast late. A slight chance of showers. A slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .SATURDAY NIGHT...West winds 10 to 20 knots becoming northwest 15 to 25 knots after midnight. A chance of showers and thunderstorms through midnight. Waves building to 1 to 3 feet. .SUNDAY...Northwest winds 15 to 25 knots diminishing to 10 to 20 knots by mid afternoon. Waves subsiding to calm to 2 feet. .SUNDAY NIGHT...Northwest winds 10 to 20 knots becoming north 5 to 15 knots after midnight. Waves calm to 2 feet. .MONDAY...East winds 10 to 20 knots diminishing to 5 to 15 knots. Waves calm to 2 feet. .TUESDAY...Southwest winds 5 to 15 knots veering west. Waves calm to 2 feet. $$ LSZ263-201545- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 343 AM EDT Fri Sep 20 2024 .EARLY THIS MORNING...South winds 10 to 20 knots. A chance of showers and a slight chance of thunderstorms. Waves 2 to 4 feet subsiding to 1 to 3 feet. .TODAY...Southwest winds 10 to 20 knots becoming west 15 to 25 knots late. Waves building to 2 to 4 feet. .TONIGHT...West winds 5 to 15 knots. Waves subsiding to calm to 2 feet. .SATURDAY...South winds less than 10 knots becoming southeast 5 to 15 knots in the afternoon, then backing east late. A slight chance of showers and thunderstorms by mid afternoon. Waves calm to 2 feet. .SATURDAY NIGHT...West winds 10 to 20 knots veering northwest after midnight. A chance of showers and thunderstorms. Waves building to 2 to 4 feet. .SUNDAY...Northwest winds 10 to 20 knots. Waves subsiding to 1 to 3 feet. .SUNDAY NIGHT...Northwest winds 5 to 15 knots veering north after midnight. Waves subsiding to calm to 2 feet. .MONDAY...North winds 10 to 20 knots becoming east 5 to 15 knots. Waves calm to 2 feet. .TUESDAY...Southwest winds 5 to 15 knots veering west. Waves calm to 2 feet. $$ LSZ264-201545- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 343 AM EDT Fri Sep 20 2024 .EARLY THIS MORNING...South winds 10 to 20 knots. Showers likely and a chance of thunderstorms. Waves 3 to 6 feet occasionally to 8 feet. .TODAY...South winds 10 to 20 knots veering southwest in the afternoon. A slight chance of showers and thunderstorms through early afternoon. Waves subsiding to 1 to 3 feet. .TONIGHT...Southwest winds 5 to 15 knots veering northwest late. Waves subsiding to calm to 2 feet. .SATURDAY...West winds less than 10 knots becoming south 5 to 15 knots in the afternoon, then backing southeast late. A slight chance of showers by mid afternoon. Waves calm to 2 feet. .SATURDAY NIGHT...South winds 10 to 20 knots veering northwest after midnight. A chance of showers and a slight chance of thunderstorms. Waves building to 2 to 4 feet. .SUNDAY...Northwest winds 10 to 20 knots. Waves subsiding to 1 to 3 feet. .SUNDAY NIGHT...Northwest winds 5 to 15 knots veering north after midnight. Waves subsiding to calm to 2 feet. .MONDAY...North winds 10 to 20 knots becoming east 5 to 15 knots. Waves calm to 2 feet. .TUESDAY...East winds 5 to 15 knots veering southwest. Waves calm to 2 feet. $$ LSZ265-201545- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 343 AM EDT Fri Sep 20 2024 .EARLY THIS MORNING...South winds 15 to 25 knots. A chance of showers and thunderstorms. Waves 2 to 4 feet subsiding to 1 to 3 feet. .TODAY...South winds 10 to 20 knots diminishing to 5 to 15 knots late. A slight chance of showers and thunderstorms. Waves subsiding to calm to 2 feet. .TONIGHT...West winds 5 to 15 knots. Waves calm to 2 feet. .SATURDAY...West winds 5 to 15 knots backing southeast in the afternoon, then increasing to 10 to 20 knots late. Waves calm to 2 feet. .SATURDAY NIGHT...South winds 10 to 20 knots veering west after midnight. A chance of showers and a slight chance of thunderstorms. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .SUNDAY...Northwest winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .SUNDAY NIGHT...Northwest winds 10 to 20 knots veering north after midnight. Waves calm to 2 feet. .MONDAY...North winds 10 to 20 knots veering northeast. Waves calm to 2 feet. .TUESDAY...Northeast winds 10 to 20 knots backing west. Waves calm to 2 feet. $$ LSZ266-201545- 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- 343 AM EDT Fri Sep 20 2024 .EARLY THIS MORNING...South winds 15 to 25 knots. Showers likely and a chance of thunderstorms. Waves 3 to 6 feet occasionally to 8 feet. .TODAY...South winds 10 to 20 knots diminishing to 5 to 15 knots late. A chance of showers and thunderstorms. Waves subsiding to 1 to 3 feet. .TONIGHT...South winds 5 to 15 knots veering west late. A slight chance of showers and thunderstorms through midnight. Patchy fog after midnight. Waves subsiding to calm to 2 feet. .SATURDAY...West winds 5 to 15 knots backing southeast late. Patchy dense fog through early afternoon. Waves calm to 2 feet. .SATURDAY NIGHT...South winds 10 to 20 knots veering west after midnight. A chance of showers and thunderstorms. Waves building to 2 to 4 feet. .SUNDAY...Northwest winds 10 to 20 knots. A chance of showers. Waves 2 to 4 feet. .SUNDAY NIGHT...Northwest winds 10 to 20 knots veering north after midnight. Waves subsiding to 1 to 3 feet. .MONDAY...North winds 10 to 20 knots veering northeast. Waves subsiding to calm to 2 feet. .TUESDAY...Northeast winds 10 to 20 knots backing west. Waves calm to 2 feet. $$ LSZ267-201545- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 343 AM EDT Fri Sep 20 2024 .EARLY THIS MORNING...South winds 10 to 20 knots. A chance of showers and a slight chance of thunderstorms. Waves 1 to 3 feet. .TODAY...Southeast winds 10 to 20 knots veering south late. Showers likely through early afternoon. A chance of thunderstorms. A chance of showers by mid afternoon. Waves subsiding to calm to 2 feet. .TONIGHT...South winds 5 to 15 knots. A chance of showers and a slight chance of thunderstorms. Patchy fog after midnight. Waves calm to 2 feet. .SATURDAY...West winds 5 to 15 knots backing east late. Patchy fog through early afternoon. Waves calm to 2 feet. .SATURDAY NIGHT...South winds 10 to 20 knots. A chance of showers. A slight chance of thunderstorms after midnight. Waves calm to 2 feet. .SUNDAY...Northwest winds 10 to 20 knots. Showers likely through early afternoon. A chance of thunderstorms. A chance of showers by mid afternoon. Waves building to 2 to 4 feet. .SUNDAY NIGHT...Northwest winds 10 to 20 knots veering north after midnight. A chance of showers. Waves subsiding to 1 to 3 feet. .MONDAY...North winds 10 to 20 knots veering northeast. A chance of showers. Waves subsiding to calm to 2 feet. .TUESDAY...Northeast winds 10 to 20 knots backing northwest. A chance of showers. Waves calm to 2 feet. $$ LSZ261-201545- MAFOR 2009/ Superior West 13520 12530 11610 11510 11610. Waves 1 to 3 feet. Superior North Central 11436 12420 12520 12510 11610. A chance of thunderstorms this morning. Waves 3 to 5 feet subsiding to 1 to 3 feet today through tonight. Superior South Central 12420 11410 12300 13600. A chance of showers and thunderstorms this morning. Waves 1 to 3 feet today. Waves 1 foot or less tonight. Superior East 13326 11310 12410 11400 11500. A chance of thunderstorms today. 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