Great Lakes Forecast
Issued by NWS
Issued by NWS
388 FZUS63 KMQT 192214 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 614 PM EDT Thu Sep 19 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...A 29.3 inch low pressure over Lake Winnipeg sends a 29.7 inch trough sweeping east into Lake Superior this evening. As the low continues to track northeast to Hudson Bay on Friday, the associated trough will fill to 29.8 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. LSZ162-200615- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 614 PM EDT Thu Sep 19 2024 /514 PM CDT Thu Sep 19 2024/ ...TORNADO WATCH 678 IN EFFECT UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT... .LATE THIS AFTERNOON...East winds 10 to 20 knots. Scattered showers and thunderstorms. Some thunderstorms may be severe with wind gusts over 35 knots, large hail, and tornadoes. Waves calm to 2 feet. .TONIGHT...South winds 10 to 20 knots veering southwest after midnight. A chance of showers and thunderstorms. Some thunderstorms may be severe with wind gusts over 35 knots, large hail, and tornadoes through late evening. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .FRIDAY...Southwest winds 5 to 15 knots increasing to 10 to 20 knots in the afternoon. Waves building to 1 to 3 feet. .FRIDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm to 2 feet. .SATURDAY...South winds 5 to 15 knots increasing to 10 to 20 knots by mid afternoon. A slight chance of showers and thunderstorms by mid afternoon. Waves calm to 2 feet. .SATURDAY NIGHT...Northwest winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .SUNDAY...Northwest winds 10 to 20 knots backing west by mid afternoon. Waves calm to 2 feet. .SUNDAY NIGHT...North winds 10 to 20 knots. Waves calm to 2 feet. .MONDAY...Northeast winds 10 to 20 knots. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .TUESDAY...North winds 10 to 20 knots backing west. Waves calm to 2 feet. $$ LSZ263-200615- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 614 PM EDT Thu Sep 19 2024 .LATE THIS AFTERNOON...Southeast winds 10 to 20 knots. Isolated showers and thunderstorms. Waves 1 to 3 feet. .TONIGHT...South winds 10 to 20 knots. A chance of showers and thunderstorms. Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet. .FRIDAY...Southwest winds 5 to 15 knots veering west late. A slight chance of showers and thunderstorms through early afternoon. Waves 1 to 3 feet. .FRIDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm to 2 feet. .SATURDAY...South winds 5 to 15 knots. A slight chance of showers by mid afternoon. Waves calm to 2 feet. .SATURDAY NIGHT...West winds 10 to 20 knots veering northwest after midnight. A chance of showers. Waves building to 1 to 3 feet. .SUNDAY...Northwest winds 10 to 20 knots. Waves subsiding to calm to 2 feet. .SUNDAY NIGHT...Northwest winds 5 to 15 knots veering north after midnight. Waves calm to 2 feet. .MONDAY...Northeast winds 10 to 20 knots. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .TUESDAY...North winds 10 to 20 knots becoming west 5 to 15 knots. Waves calm to 2 feet. $$ LSZ264-200615- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 614 PM EDT Thu Sep 19 2024 .LATE THIS AFTERNOON...Southeast winds 10 to 20 knots. Isolated showers. Waves 2 to 4 feet. .TONIGHT...Southeast winds 15 to 25 knots veering south after midnight, then diminishing to 10 to 20 knots late. A chance of showers and thunderstorms. Waves building to 3 to 6 feet occasionally to 8 feet. .FRIDAY...South winds 5 to 15 knots veering southwest in the afternoon. A slight chance of showers and thunderstorms through early afternoon. Waves subsiding to 1 to 3 feet. .FRIDAY NIGHT...Southwest winds 5 to 15 knots veering northwest late. Waves subsiding to calm to 2 feet. .SATURDAY...South winds 5 to 15 knots backing southeast by mid afternoon. Waves calm to 2 feet. .SATURDAY NIGHT...South winds 10 to 20 knots veering northwest after midnight. A chance of showers. Waves building to 1 to 3 feet. .SUNDAY...Northwest winds 10 to 20 knots. Waves subsiding to calm to 2 feet. .SUNDAY NIGHT...Northwest winds 5 to 15 knots veering north after midnight. Waves calm to 2 feet. .MONDAY...Northeast winds 10 to 20 knots diminishing to 5 to 15 knots. A chance of showers. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .TUESDAY...Northeast winds 5 to 15 knots backing west. Waves calm to 2 feet. $$ LSZ265-200615- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 614 PM EDT Thu Sep 19 2024 .LATE THIS AFTERNOON...Southeast winds 15 to 25 knots. Isolated showers. Waves 2 to 4 feet. .TONIGHT...Southeast winds 15 to 25 knots. A chance of showers and thunderstorms. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet. .FRIDAY...South winds 5 to 15 knots. A slight chance of showers and thunderstorms. Waves subsiding to calm to 2 feet. .FRIDAY NIGHT...Southwest winds 5 to 15 knots veering west after midnight. Waves calm to 2 feet. .SATURDAY...West winds 5 to 15 knots becoming southeast 10 to 20 knots by mid afternoon. Waves calm to 2 feet. .SATURDAY NIGHT...South winds 10 to 20 knots veering northwest after midnight. A chance of showers. Waves calm to 2 feet. .SUNDAY...Northwest winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .SUNDAY NIGHT...North winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .MONDAY...Northeast winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .TUESDAY...North winds 10 to 20 knots backing west. A chance of showers. Waves calm to 2 feet. $$ LSZ266-200615- 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- 614 PM EDT Thu Sep 19 2024 .LATE THIS AFTERNOON...Southeast winds 15 to 25 knots. Waves 2 to 4 feet. .TONIGHT...South winds 15 to 25 knots. A chance of showers and thunderstorms. Waves building to 3 to 6 feet occasionally to 8 feet. .FRIDAY...South winds 15 to 25 knots diminishing to 5 to 15 knots in the afternoon. A chance of showers and thunderstorms. Waves subsiding to 1 to 3 feet. .FRIDAY NIGHT...South winds 5 to 15 knots veering west late. A slight chance of showers and thunderstorms through midnight. Waves subsiding to calm to 2 feet. .SATURDAY...West winds 5 to 15 knots backing southeast by mid afternoon. Waves calm to 2 feet. .SATURDAY NIGHT...South winds 10 to 20 knots veering west after midnight. A chance of showers. Waves building to 1 to 3 feet. .SUNDAY...Northwest winds 10 to 20 knots. A chance of showers. Waves subsiding to calm to 2 feet. .SUNDAY NIGHT...North winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .MONDAY...Northeast winds 10 to 20 knots. A chance of showers. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .TUESDAY...North winds 10 to 20 knots backing northwest. A chance of showers. Waves calm to 2 feet. $$ LSZ267-200615- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 614 PM EDT Thu Sep 19 2024 .LATE THIS AFTERNOON...Southeast winds 10 to 20 knots. Waves calm to 2 feet. .TONIGHT...South winds 10 to 20 knots backing southeast after midnight, then increasing to 15 to 25 knots late. A chance of showers and a slight chance of thunderstorms after midnight. Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet. .FRIDAY...Southeast winds 15 to 25 knots becoming south 10 to 20 knots late. A chance of showers and thunderstorms. Waves subsiding to 1 to 3 feet. .FRIDAY NIGHT...South winds 10 to 20 knots diminishing to 5 to 15 knots after midnight, then veering southwest late. A chance of showers and thunderstorms through midnight. Waves subsiding to calm to 2 feet. .SATURDAY...Southwest winds 5 to 15 knots backing southeast by mid afternoon. Waves calm to 2 feet. .SATURDAY NIGHT...South winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .SUNDAY...Northwest winds 10 to 20 knots. A chance of showers. Waves building to 1 to 3 feet. .SUNDAY NIGHT...North winds 10 to 20 knots. Showers likely through midnight. A chance of showers after midnight. Waves subsiding to calm to 2 feet. .MONDAY...Northeast winds 10 to 20 knots veering east. A chance of showers and thunderstorms. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .TUESDAY...East winds 10 to 20 knots backing northwest. A chance of showers. Waves calm to 2 feet. $$ LSZ261-200615- MAFOR 1921 AMD/ Superior West...TORNADO WATCH IN EFFECT...11320 11420 19429 12520 19529 11520 11510 12520. Waves 1 to 3 feet. Superior North Central 12330 11430 19439 11436 19439 11430 19439 11420 12510. Waves 2 to 4 feet building to 3 to 6 feet tonight. Waves 3 to 5 feet subsiding to 2 to 4 feet Friday. Superior South Central 11320 11330 11330 19339 11426 19429 11320 19329 12420 11300. Waves 2 to 4 feet tonight. Waves 1 to 3 feet Friday. Superior East 11310 11420 11320 12320 19326 12320 11420. Waves 1 to 3 feet building to 2 to 4 feet tonight. Waves 2 to 4 feet Friday. $$ 07 Experimental modernized open lake forecast is available online at weather.gov/mqt/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes