Great Lakes Forecast
Issued by NWS
Issued by NWS
491 FZUS63 KMQT 201349 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 949 AM EDT Mon May 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...A 29.8 inch low pressure system is shifting east from Iowa to Lake Michigan today. A period of weak 29.9 inch ridging follows for late tonight into Tuesday morning over Lake Superior. A 29.4 inch low pressure develops over the Plains Tuesday, then deepens to 29.2 inches as it lifts northeast, eventually tracking over western Lake Superior late Tuesday night. The low continues toward James Bay Wednesday and Wednesday night as it weakens to 29.4 inches. 29.9 inch ridging builds in by Thursday across Lake Superior. This ridging shifts east as a 29.6 inch low lifts from the Northern Plains into Canadian Prairie Thursday night into Friday. Weak troughing of 29.8 inches moves over Lake Superior by Saturday. LSZ162-202200- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 949 AM EDT Mon May 20 2024 /849 AM CDT Mon May 20 2024/ ...GALE WATCH IN EFFECT FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING... .REST OF TODAY...Northeast winds 5 to 15 knots. A chance of rain showers. Waves calm to 2 feet. .TONIGHT...Northeast winds 5 to 15 knots backing north after midnight, then veering northeast late. Waves calm to 2 feet. .TUESDAY...Northeast winds 5 to 15 knots increasing to 20 to 30 knots. A chance of rain showers. A slight chance of thunderstorms by mid afternoon. Waves building to 5 to 8 feet occasionally to 10 feet. .TUESDAY NIGHT...Northeast gales to 35 knots. Showers and a chance of thunderstorms. Waves building to 9 to 12 feet occasionally to 15 feet. .WEDNESDAY...West gales to 40 knots. Showers likely. Waves subsiding to 4 to 7 feet occasionally to 9 feet. .WEDNESDAY NIGHT...West winds 20 to 30 knots. A chance of rain showers. Waves subsiding to 2 to 4 feet. .THURSDAY...West winds 15 to 25 knots becoming northeast 10 to 20 knots. Waves subsiding to calm to 2 feet. .FRIDAY...East winds 10 to 20 knots increasing to 15 to 25 knots. A chance of rain showers. Waves building to 2 to 4 feet. $$ LSZ263-202200- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 949 AM EDT Mon May 20 2024 ...GALE WATCH IN EFFECT FROM LATE TUESDAY NIGHT THROUGH LATE WEDNESDAY NIGHT... .REST OF TODAY...Northeast winds less than 10 knots increasing to 5 to 15 knots in the afternoon, then diminishing to less than 10 knots late. A chance of showers. Waves calm to 2 feet. .TONIGHT...Northeast winds less than 10 knots backing north after midnight. Waves calm to 2 feet. .TUESDAY...Northeast winds 5 to 15 knots increasing to 15 to 25 knots. A chance of rain showers and a slight chance of thunderstorms by mid afternoon. Waves building to 4 to 7 feet occasionally to 9 feet. .TUESDAY NIGHT...East gales to 35 knots. Showers and a chance of thunderstorms. Waves building to 8 to 11 feet occasionally to 14 feet. .WEDNESDAY...Southwest gales to 35 knots veering west by mid afternoon. Showers likely through early afternoon, then a chance of showers by mid afternoon. Waves subsiding to 6 to 9 feet occasionally to 11 feet. .WEDNESDAY NIGHT...West gales to 35 knots diminishing to 20 to 30 knots after midnight. A chance of rain showers. Waves subsiding to 3 to 6 feet occasionally to 8 feet. .THURSDAY...West winds 20 to 30 knots becoming east 5 to 15 knots. Waves subsiding to calm to 2 feet. .FRIDAY...East winds 10 to 20 knots. A chance of rain showers. Waves building to 1 to 3 feet. $$ LSZ264-202200- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 949 AM EDT Mon May 20 2024 ...GALE WATCH IN EFFECT FROM LATE TUESDAY NIGHT THROUGH LATE WEDNESDAY NIGHT... .REST OF TODAY...East winds 5 to 15 knots becoming northeast less than 10 knots late. A chance of rain showers. Waves calm to 2 feet. .TONIGHT...Northeast winds less than 10 knots backing northwest after midnight, then veering north late. Waves calm to 2 feet. .TUESDAY...North winds 5 to 15 knots veering northeast in the afternoon, then becoming east 10 to 20 knots late. A slight chance of showers by mid afternoon. Waves building to 1 to 3 feet. .TUESDAY NIGHT...East winds 20 to 30 knots increasing to gales to 35 knots after midnight. Showers and a chance of thunderstorms. Waves building to 8 to 11 feet occasionally to 14 feet. .WEDNESDAY...South gales to 35 knots veering west by mid afternoon. Showers likely through early afternoon, then a chance of showers by mid afternoon. Waves building to 9 to 12 feet occasionally to 15 feet, then subsiding to 6 to 9 feet occasionally to 11 feet. .WEDNESDAY NIGHT...West winds 20 to 30 knots. A chance of rain showers. Waves subsiding to 4 to 7 feet occasionally to 9 feet. .THURSDAY...West winds 20 to 30 knots becoming northwest 5 to 15 knots. Waves subsiding to calm to 2 feet. .FRIDAY...Southeast winds 5 to 15 knots increasing to 10 to 20 knots. A chance of rain showers. Waves building to 1 to 3 feet. $$ LSZ265-202200- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 949 AM EDT Mon May 20 2024 ...GALE WATCH IN EFFECT FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY AFTERNOON... .REST OF TODAY...South winds 10 to 20 knots backing southeast in the afternoon, then becoming east 5 to 15 knots late. A chance of showers. Waves calm to 2 feet. .TONIGHT...Northeast winds 5 to 15 knots backing northwest after midnight, then veering north late. A slight chance of rain showers through midnight. Waves calm to 2 feet. .TUESDAY...Northeast winds 5 to 15 knots veering east in the afternoon, then increasing to 10 to 20 knots late. A slight chance of showers by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...East winds 20 to 30 knots becoming southeast gales to 40 knots after midnight. Showers and a chance of thunderstorms. Waves building to 3 to 6 feet occasionally to 8 feet. .WEDNESDAY...South gales to 40 knots veering southwest by mid afternoon. A chance of showers. Waves subsiding to 3 to 5 feet occasionally to 7 feet. .WEDNESDAY NIGHT...West winds 20 to 30 knots. A chance of showers. Waves 3 to 5 feet occasionally to 7 feet. .THURSDAY...West winds 15 to 25 knots becoming northwest 10 to 20 knots. Waves subsiding to calm to 2 feet. .FRIDAY...East winds 10 to 20 knots veering southeast. A chance of rain showers. Waves calm to 2 feet. $$ LSZ266-202200- 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- 949 AM EDT Mon May 20 2024 ...GALE WATCH IN EFFECT FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY AFTERNOON... .REST OF TODAY...South winds 10 to 20 knots becoming southeast 5 to 15 knots late. A chance of showers. A slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .TONIGHT...Southeast winds 5 to 15 knots veering northwest after midnight, then veering north late. A slight chance of rain showers through midnight. Waves calm to 2 feet. .TUESDAY...North winds 5 to 15 knots veering northeast in the afternoon, then becoming east 10 to 20 knots late. A slight chance of rain showers by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...East winds 20 to 30 knots becoming southeast gales to 40 knots after midnight. Showers and a chance of thunderstorms. Waves building to 5 to 8 feet occasionally to 10 feet. .WEDNESDAY...South gales to 40 knots becoming southwest gales to 35 knots by mid afternoon. A chance of showers. Waves building to 5 to 9 feet occasionally to 11 feet. .WEDNESDAY NIGHT...West winds 20 to 30 knots. A chance of rain showers. Waves subsiding to 5 to 8 feet occasionally to 10 feet. .THURSDAY...West winds 15 to 25 knots becoming northwest 10 to 20 knots. Waves subsiding to 1 to 3 feet. .FRIDAY...Southeast winds 10 to 20 knots. A chance of rain showers. Waves subsiding to calm to 2 feet. $$ LSZ267-202200- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 949 AM EDT Mon May 20 2024 ...GALE WATCH IN EFFECT FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY AFTERNOON... .REST OF TODAY...Southeast winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .TONIGHT...Southeast winds 5 to 15 knots veering west after midnight, then veering north late. A slight chance of thunderstorms through midnight. A chance of rain showers. Waves calm to 2 feet. .TUESDAY...Northwest winds 5 to 15 knots veering north in the afternoon, then becoming northeast 10 to 20 knots late. Waves calm to 2 feet. .TUESDAY NIGHT...East winds 15 to 25 knots becoming southeast gales to 40 knots after midnight. Showers and a chance of thunderstorms. Waves building to 3 to 6 feet occasionally to 8 feet. .WEDNESDAY...South gales to 35 knots veering southwest by mid afternoon. A chance of showers. Waves 3 to 6 feet occasionally to 8 feet. .WEDNESDAY NIGHT...West winds 20 to 30 knots. A chance of rain showers. Waves building to 4 to 7 feet occasionally to 9 feet. .THURSDAY...West winds 20 to 30 knots becoming northwest 10 to 20 knots. Waves subsiding to 1 to 3 feet. .FRIDAY...Northwest winds 10 to 20 knots backing southeast. A chance of rain showers. Waves subsiding to calm to 2 feet. $$ LSZ261-202200- MAFOR 2015/ Superior West 11200 13100 12700 11100 11110. A chance of showers this afternoon. Waves 1 foot or less. Superior North Central 11200 11300 12200 12700 11800 11700. A chance of showers this afternoon. Waves 1 foot or less. Superior South Central 14310 11600 11700 12800. A chance of showers this afternoon. Waves 2 feet or less. Superior East 13310 11300 11500 11700 11800 11700. A chance of showers this afternoon and evening. Waves 2 feet or less. $$ TAP Experimental modernized open lake forecast is available online at weather.gov/mqt/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes