Great Lakes Forecast
Issued by NWS
Issued by NWS
499 FZUS63 KMQT 211954 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 354 PM EDT Tue May 21 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 29.4 inch low pressure currently over western Iowa deepens to 29.0 inches as it lifts north-northeast, eventually tracking over western Lake Superior into Ontario late tonight and early Wednesday. The low continues north into Ontario during the day Wednesday and into Wednesday night as it weakens to 29.4 inches. 29.9 inch ridging builds in Thursday across Lake Superior as the low slowly moves east toward James Bay. This ridging shifts east as a 29.6 inch low lifts northeast through the Northern Plains Thursday night into Friday. Weak troughing of 29.8 inches moves over Lake Superior by Saturday. LSZ162-220400- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 354 PM EDT Tue May 21 2024 /254 PM CDT Tue May 21 2024/ ...GALE WARNING IN EFFECT THROUGH WEDNESDAY EVENING... .LATE THIS AFTERNOON...Northeast gales to 35 knots. Patchy dense fog. Showers and scattered thunderstorms. Waves 5 to 8 feet occasionally to 10 feet building to 7 to 10 feet occasionally to 13 feet. .TONIGHT...East gales to 35 knots veering south late. Patchy fog. Showers through midnight. A chance of thunderstorms. A chance of showers after midnight. Waves building to 8 to 11 feet occasionally to 14 feet, then subsiding to 5 to 8 feet occasionally to 10 feet. .WEDNESDAY...Southwest gales to 40 knots veering west in the afternoon. A slight chance of thunderstorms through early afternoon. A chance of showers. Waves building to 9 to 12 feet occasionally to 15 feet, then subsiding to 5 to 8 feet occasionally to 10 feet. .WEDNESDAY NIGHT...West winds 20 to 30 knots diminishing to 15 to 25 knots after midnight. A slight chance of rain showers through midnight. Waves subsiding to 3 to 5 feet occasionally to 7 feet. .THURSDAY...West winds 10 to 20 knots backing southwest by mid afternoon. A slight chance of showers and thunderstorms by mid afternoon. Waves subsiding to 1 to 3 feet. .THURSDAY NIGHT...North winds 10 to 20 knots veering northeast after midnight. A chance of rain showers. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. .FRIDAY...Northeast winds 15 to 25 knots increasing to 20 to 30 knots by mid afternoon. A chance of rain showers through early afternoon, then rain showers likely and a chance of thunderstorms by mid afternoon. Waves building to 4 to 7 feet occasionally to 9 feet. .FRIDAY NIGHT...Northeast winds 15 to 25 knots backing west after midnight. Rain showers likely through midnight. A chance of thunderstorms. A chance of rain showers after midnight. Waves subsiding to 3 to 5 feet occasionally to 7 feet. .SATURDAY...West winds 15 to 25 knots diminishing to 10 to 20 knots. A chance of showers. Waves subsiding to calm to 2 feet. .SUNDAY...West winds 10 to 20 knots veering northeast. Waves calm to 2 feet. $$ LSZ263-220400- 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- 354 PM EDT Tue May 21 2024 ...GALE WARNING IN EFFECT FROM 10 PM EDT THIS EVENING THROUGH WEDNESDAY EVENING... .LATE THIS AFTERNOON...East winds 20 to 30 knots. Scattered showers and isolated thunderstorms. Waves 3 to 6 feet occasionally to 8 feet building to 4 to 7 feet occasionally to 9 feet. .TONIGHT...East gales to 35 knots veering southeast late. Patchy fog. Showers through midnight. A chance of thunderstorms. A chance of showers after midnight. Waves building to 6 to 10 feet occasionally to 13 feet. .WEDNESDAY...Southwest gales to 45 knots veering west late. A slight chance of thunderstorms through early afternoon. A chance of showers. Waves building to 11 to 15 feet occasionally to 19 feet, then subsiding to 9 to 12 feet occasionally to 15 feet. .WEDNESDAY NIGHT...West winds 20 to 30 knots. A chance of rain showers through midnight. Waves subsiding to 4 to 7 feet occasionally to 9 feet. .THURSDAY...West winds 15 to 25 knots becoming southwest 10 to 20 knots by mid afternoon. A slight chance of showers and thunderstorms by mid afternoon. Waves subsiding to 2 to 4 feet. .THURSDAY NIGHT...Northwest winds 5 to 15 knots veering northeast after midnight. Waves subsiding to calm to 2 feet. .FRIDAY...Northeast winds 10 to 20 knots becoming east 15 to 25 knots by mid afternoon. A chance of rain showers. A chance of thunderstorms by mid afternoon. Waves building to 3 to 5 feet occasionally to 7 feet. .FRIDAY NIGHT...East winds 10 to 20 knots becoming west 15 to 25 knots after midnight. Rain showers likely through midnight. A chance of thunderstorms. A chance of rain showers after midnight. Waves 3 to 5 feet occasionally to 7 feet. .SATURDAY...West winds 15 to 25 knots diminishing to 5 to 15 knots. A chance of rain showers. Waves subsiding to calm to 2 feet. .SUNDAY...West winds 5 to 15 knots veering northeast. Waves calm to 2 feet. $$ LSZ264-220400- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 354 PM EDT Tue May 21 2024 ...GALE WARNING IN EFFECT FROM 10 PM EDT THIS EVENING THROUGH WEDNESDAY EVENING... .LATE THIS AFTERNOON...East winds 15 to 25 knots. Patchy fog. Numerous showers. Waves 2 to 4 feet. .TONIGHT...East winds 20 to 30 knots increasing to gales to 35 knots after midnight, then veering southeast late. Patchy fog. Showers through midnight. A chance of thunderstorms. A chance of showers after midnight. Waves building to 8 to 11 feet occasionally to 14 feet. .WEDNESDAY...South gales to 40 knots becoming southwest gales to 45 knots in the afternoon. Patchy fog through early afternoon. A slight chance of thunderstorms through early afternoon. A chance of showers. Waves subsiding to 7 to 10 feet occasionally to 13 feet, then building to 11 to 15 feet occasionally to 19 feet. .WEDNESDAY NIGHT...Southwest gales to 35 knots becoming west 20 to 30 knots after midnight. A chance of rain showers through midnight. Waves subsiding to 5 to 8 feet occasionally to 10 feet. .THURSDAY...West winds 15 to 25 knots becoming southwest 10 to 20 knots by mid afternoon. Waves subsiding to 2 to 4 feet. .THURSDAY NIGHT...West winds 5 to 15 knots veering north after midnight. Waves subsiding to calm to 2 feet. .FRIDAY...Northeast winds 10 to 20 knots veering east by mid afternoon. A chance of rain showers. Waves building to 1 to 3 feet. .FRIDAY NIGHT...East winds 10 to 20 knots becoming south 15 to 25 knots after midnight. Showers likely and a chance of thunderstorms. Waves building to 3 to 5 feet occasionally to 7 feet. .SATURDAY...Southwest winds 15 to 25 knots becoming west 5 to 15 knots. A chance of showers. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to calm to 2 feet. .SUNDAY...Northwest winds 5 to 15 knots veering north. Waves calm to 2 feet. $$ LSZ265-220400- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 354 PM EDT Tue May 21 2024 ...GALE WARNING IN EFFECT FROM 2 AM EDT WEDNESDAY THROUGH WEDNESDAY MORNING... .LATE THIS AFTERNOON...East winds 15 to 25 knots. Scattered showers. Waves 1 to 3 feet building to 2 to 4 feet. .TONIGHT...East winds 20 to 30 knots becoming southeast gales to 35 knots after midnight. Patchy fog. Showers likely through midnight. A chance of thunderstorms. A chance of showers after midnight. Waves building to 4 to 8 feet occasionally to 10 feet. .WEDNESDAY...Southwest winds 20 to 30 knots increasing to gales to 35 knots in the afternoon, then veering west late. A chance of showers by mid afternoon. Waves subsiding to 3 to 6 feet occasionally to 8 feet. .WEDNESDAY NIGHT...West winds 15 to 25 knots backing southwest after midnight, then veering west late. A chance of showers through midnight. Waves subsiding to 1 to 3 feet. .THURSDAY...West winds 15 to 25 knots diminishing to 10 to 20 knots by mid afternoon. A slight chance of showers and thunderstorms by mid afternoon. Waves subsiding to calm to 2 feet. .THURSDAY NIGHT...West winds 5 to 15 knots veering north after midnight. Waves calm to 2 feet. .FRIDAY...Northeast winds 5 to 15 knots becoming east 15 to 25 knots by mid afternoon. A chance of rain showers. A chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .FRIDAY NIGHT...East winds 10 to 20 knots veering west after midnight. Showers likely through midnight. A chance of thunderstorms. A chance of showers after midnight. Waves building to 1 to 3 feet. .SATURDAY...West winds 15 to 25 knots diminishing to 10 to 20 knots. A chance of showers. Waves subsiding to calm to 2 feet. .SUNDAY...West winds 10 to 20 knots becoming north 5 to 15 knots. Waves calm to 2 feet. $$ LSZ266-220400- 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- 354 PM EDT Tue May 21 2024 ...GALE WARNING IN EFFECT FROM 2 AM EDT WEDNESDAY THROUGH WEDNESDAY MORNING... .LATE THIS AFTERNOON...East winds 15 to 25 knots. Scattered showers. Waves calm to 2 feet building to 1 to 3 feet. .TONIGHT...East winds 20 to 30 knots becoming southeast gales to 40 knots after midnight. A chance of showers and thunderstorms. Patchy fog after midnight. Waves building to 7 to 10 feet occasionally to 13 feet. .WEDNESDAY...South winds 20 to 30 knots with a few gale force gusts to 35 knots in the afternoon. A slight chance of showers. Waves subsiding to 5 to 8 feet occasionally to 10 feet, then building to 10 to 14 feet occasionally to 18 feet. .WEDNESDAY NIGHT...Southwest winds 20 to 30 knots. A chance of rain showers through midnight. Waves subsiding to 5 to 8 feet occasionally to 10 feet. .THURSDAY...West 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 2 to 4 feet. .THURSDAY NIGHT...West winds 5 to 15 knots veering north after midnight. Waves subsiding to calm to 2 feet. .FRIDAY...Northeast winds 5 to 15 knots becoming east 10 to 20 knots by mid afternoon. A chance of rain showers by mid afternoon. Waves calm to 2 feet. .FRIDAY NIGHT...East winds 10 to 20 knots veering southeast after midnight. Showers likely and a chance of thunderstorms. Waves building to 2 to 4 feet. .SATURDAY...West winds 15 to 25 knots diminishing to 10 to 20 knots. A chance of rain showers. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 1 to 3 feet. .SUNDAY...Northwest winds 10 to 20 knots becoming north 5 to 15 knots. Waves subsiding to calm to 2 feet. $$ LSZ267-220400- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 354 PM EDT Tue May 21 2024 ...GALE WARNING IN EFFECT FROM 2 AM EDT WEDNESDAY THROUGH WEDNESDAY MORNING... .LATE THIS AFTERNOON...East winds 10 to 20 knots. Isolated showers. Waves calm to 2 feet. .TONIGHT...East winds 15 to 25 knots becoming southeast 20 to 30 knots after midnight, then increasing to gales to 35 knots late. A chance of showers and thunderstorms. Waves building to 5 to 8 feet occasionally to 10 feet. .WEDNESDAY...South winds 20 to 30 knots diminishing to 15 to 25 knots in the afternoon, then veering southwest late. A slight chance of showers. Waves subsiding to 1 to 3 feet. .WEDNESDAY NIGHT...Southwest winds 10 to 20 knots increasing to 15 to 25 knots late. A chance of showers through midnight. Waves building to 3 to 6 feet occasionally to 8 feet. .THURSDAY...West winds 15 to 25 knots diminishing to 10 to 20 knots by mid afternoon. A slight chance of showers and thunderstorms by mid afternoon. Waves subsiding to 1 to 3 feet. .THURSDAY NIGHT...West winds 10 to 20 knots veering northwest after midnight. Waves subsiding to calm to 2 feet. .FRIDAY...North winds 10 to 20 knots veering northeast by mid afternoon. A chance of showers by mid afternoon. Waves calm to 2 feet. .FRIDAY NIGHT...East winds 10 to 20 knots becoming southeast 15 to 25 knots after midnight. A chance of showers through midnight. A chance of thunderstorms. Showers likely after midnight. Waves building to 2 to 4 feet. .SATURDAY...West winds 15 to 25 knots diminishing to 10 to 20 knots. A chance of rain showers. Waves subsiding to calm to 2 feet. .SUNDAY...West winds 10 to 20 knots veering north. Waves calm to 2 feet. $$ LSZ261-220400- MAFOR 2121/ Superior West...GALE WARNING IN EFFECT...11256 19259 12256 11340 11450 12550 11650. Waves 5 to 7 feet building to 7 to 11 feet, then subsiding to 5 to 8 feet tonight. Waves 5 to 8 feet building to 8 to 12 feet Wednesday. Superior North Central...GALE WARNING IN EFFECT...11236 11240 11256 12350 11450 12560. A chance of thunderstorms tonight. Waves 1 to 2 feet building to 7 to 10 feet tonight, then building to 10 to 15 feet Wednesday. Superior South Central...GALE WARNING IN EFFECT...11230 19236 11230 11346 12350 11440 11530 11540. A chance of thunderstorms tonight. Waves 1 to 2 feet building to 5 to 7 feet tonight then subsiding to 3 to 6 feet Wednesday. Superior East...GALE WARNING IN EFFECT...11220 11230 11340 11356 11350 12440 11530. A chance of thunderstorms overnight. Waves 1 to 3 feet building to 5 to 8 feet tonight before subsiding to 3 to 5 feet Wednesday. $$ BW Experimental modernized open lake forecast is available online at weather.gov/mqt/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes