Marine Weather Forecast from Environment Canada

Lake Superior Mafor Forecast and Weather Conditions
From NOAA National Weather Service Weather Forecast Office

  
030   
FZUS63 KMQT 120801  
GLFLS   
  
OPEN LAKE FORECAST FOR LAKE SUPERIOR  
NATIONAL WEATHER SERVICE MARQUETTE MI  
401 AM EDT WED AUG 12 2026  
  
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  
  
THIS MORNING, 29.5 INCH LOW PRESSURE IS OVER THE GULF OF ST LAWRENCE   
AND DEEPENS TO 29.5 INCHES WHILE A PLAINS LOW OF 29.7 INCHES IS ONLY   
SEPARATED FROM THE FIRST LOW BY WEAK 29.8-29.9 INCH RIDGING OVER   
LAKE SUPERIOR. THIS PATTERN HOLDS UNTIL THURSDAY MORNING, WHEN A   
30.2 INCH HIGH OVER THE CANADIAN ROCKIES BEGINS TO EXTEND STRONGER   
RIDGING OVER LAKE SUPERIOR BEFORE EVENTUALLY BECOMING CENTERED OVER   
THE LAKE AT 30.2 INCHES FRIDAY AFTERNOON. A 29.9 INCH TROUGH THEN   
MOVES OVER THE WESTERN END OF THE LAKE SATURDAY AFTERNOON AS THE   
30.2 INCH HIGH MOVES OVER THE LOWER GREAT LAKES. THIS TROUGH   
CONSOLIDATES TO A 29.8 INCH LOW AS IT PASSES OVER LAKE SUPERIOR,   
REACHING ONTARIO BY SUNDAY AFTERNOON, WITH 30.1 INCH RIDGING TO   
FOLLOW.  
  
LSZ162-122000-  
LAKE SUPERIOR WEST OF A LINE FROM SAXON HARBOR WI TO GRAND  
PORTAGE MN BEYOND 5NM-  
401 AM EDT WED AUG 12 2026 /301 AM CDT WED AUG 12 2026/  
   
EARLY THIS MORNING  
NORTH WINDS LESS THAN 10 KNOTS. PATCHY FOG.  
WAVES CALM TO 2 FEET.    
TODAY  
NORTHWEST WINDS LESS THAN 10 KNOTS BECOMING SOUTH 5 TO  
15 KNOTS IN THE AFTERNOON. PATCHY DENSE FOG THROUGH EARLY  
AFTERNOON. WAVES CALM TO 2 FEET.    
TONIGHT  
NORTHEAST WINDS 5 TO 15 KNOTS BACKING NORTH AFTER  
MIDNIGHT, THEN VEERING NORTHEAST LATE. A CHANCE OF SHOWERS. WAVES  
CALM TO 2 FEET.    
THURSDAY  
NORTHEAST WINDS 5 TO 15 KNOTS VEERING EAST LATE.  
WAVES CALM TO 2 FEET.    
THURSDAY NIGHT  
NORTHEAST WINDS 5 TO 15 KNOTS. WAVES CALM TO  
2 FEET.    
FRIDAY  
NORTHEAST WINDS 10 TO 20 KNOTS INCREASING TO 15 TO  
25 KNOTS BY MID AFTERNOON. WAVES BUILDING TO 2 TO 4 FEET, THEN  
SUBSIDING TO 1 TO 3 FEET.    
FRIDAY NIGHT  
NORTHEAST WINDS 15 TO 25 KNOTS DIMINISHING TO  
5 TO 15 KNOTS AFTER MIDNIGHT. WAVES SUBSIDING TO CALM TO 2 FEET.    
SATURDAY  
NORTHEAST WINDS 5 TO 15 KNOTS BACKING NORTH. A CHANCE  
OF SHOWERS. WAVES CALM TO 2 FEET.    
SUNDAY  
WEST WINDS 5 TO 15 KNOTS VEERING NORTHWEST. WAVES CALM  
TO 2 FEET.   
  
  
  
LSZ263-122000-  
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-  
401 AM EDT WED AUG 12 2026  
   
EARLY THIS MORNING  
NORTHWEST WINDS LESS THAN 10 KNOTS. WAVES  
CALM TO 2 FEET.    
TODAY  
NORTHWEST WINDS LESS THAN 10 KNOTS INCREASING TO 5 TO  
15 KNOTS IN THE AFTERNOON, THEN BACKING SOUTH LATE. WAVES CALM TO  
2 FEET.    
TONIGHT  
EAST WINDS LESS THAN 10 KNOTS BACKING NORTH AFTER  
MIDNIGHT, THEN VEERING NORTHEAST LATE. A SLIGHT CHANCE OF SHOWERS  
AFTER MIDNIGHT. WAVES CALM TO 2 FEET.    
THURSDAY  
NORTHEAST WINDS LESS THAN 10 KNOTS INCREASING TO 5 TO  
15 KNOTS IN THE AFTERNOON. WAVES CALM TO 2 FEET.    
THURSDAY NIGHT  
NORTHEAST WINDS LESS THAN 10 KNOTS INCREASING  
TO 5 TO 15 KNOTS AFTER MIDNIGHT. WAVES CALM TO 2 FEET.    
FRIDAY  
NORTHEAST WINDS 5 TO 15 KNOTS INCREASING TO 15 TO  
25 KNOTS BY MID AFTERNOON. WAVES CALM TO 2 FEET.    
FRIDAY NIGHT  
EAST WINDS 10 TO 20 KNOTS DIMINISHING TO 5 TO  
15 KNOTS AFTER MIDNIGHT. WAVES CALM TO 2 FEET.    
SATURDAY  
EAST WINDS 5 TO 15 KNOTS BACKING NORTHWEST. A CHANCE  
OF SHOWERS. WAVES CALM TO 2 FEET.    
SUNDAY  
WEST WINDS 5 TO 15 KNOTS. WAVES CALM TO 2 FEET.   
  
  
  
LSZ264-122000-  
LAKE SUPERIOR FROM UPPER ENTRANCE TO PORTAGE CANAL TO MANITOU  
ISLAND MI 5NM OFF SHORE TO THE US/CANADIAN BORDER-  
401 AM EDT WED AUG 12 2026  
   
EARLY THIS MORNING  
WEST WINDS LESS THAN 10 KNOTS. WAVES CALM  
TO 2 FEET.    
TODAY  
WEST WINDS LESS THAN 10 KNOTS VEERING NORTHWEST IN THE  
AFTERNOON, THEN BACKING SOUTHWEST LATE. WAVES CALM TO 2 FEET.    
TONIGHT  
SOUTHWEST WINDS LESS THAN 10 KNOTS VEERING NORTHWEST  
LATE. WAVES CALM TO 2 FEET.    
THURSDAY  
NORTH WINDS LESS THAN 10 KNOTS VEERING NORTHEAST IN  
THE AFTERNOON, THEN VEERING SOUTHWEST LATE. WAVES CALM TO 2 FEET.   
THURSDAY NIGHT  
NORTH WINDS LESS THAN 10 KNOTS INCREASING TO  
5 TO 15 KNOTS AFTER MIDNIGHT. WAVES CALM TO 2 FEET.    
FRIDAY  
NORTHEAST WINDS 5 TO 15 KNOTS VEERING EAST BY MID  
AFTERNOON. WAVES CALM TO 2 FEET.    
FRIDAY NIGHT  
SOUTHEAST WINDS 5 TO 15 KNOTS. WAVES CALM TO  
2 FEET.    
SATURDAY  
SOUTHEAST WINDS 10 TO 20 KNOTS BECOMING NORTHWEST  
5 TO 15 KNOTS. A CHANCE OF SHOWERS. WAVES CALM TO 2 FEET.    
SUNDAY  
NORTHWEST WINDS 5 TO 15 KNOTS BACKING WEST. WAVES CALM  
TO 2 FEET.   
  
  
  
LSZ265-122000-  
LAKE SUPERIOR WEST OF LINE FROM MANITOU ISLAND TO MARQUETTE MI  
BEYOND 5NM FROM SHORE-  
401 AM EDT WED AUG 12 2026  
   
EARLY THIS MORNING  
WEST WINDS 5 TO 15 KNOTS. WAVES CALM TO  
2 FEET.    
TODAY  
WEST WINDS 5 TO 15 KNOTS VEERING NORTHEAST IN THE  
AFTERNOON, THEN VEERING EAST LATE. WAVES CALM TO 2 FEET.    
TONIGHT  
SOUTHEAST WINDS 5 TO 15 KNOTS BACKING NORTH LATE. A  
SLIGHT CHANCE OF SHOWERS AFTER MIDNIGHT. WAVES CALM TO 2 FEET.    
THURSDAY  
NORTH WINDS 5 TO 15 KNOTS VEERING EAST LATE. A SLIGHT  
CHANCE OF SHOWERS THROUGH EARLY AFTERNOON. WAVES CALM TO 2 FEET.    
THURSDAY NIGHT  
NORTH WINDS 5 TO 15 KNOTS. WAVES CALM TO  
2 FEET.    
FRIDAY  
NORTHEAST WINDS 5 TO 15 KNOTS. WAVES CALM TO 2 FEET.    
FRIDAY NIGHT  
SOUTHEAST WINDS 5 TO 15 KNOTS. WAVES CALM TO  
2 FEET.    
SATURDAY  
SOUTHEAST WINDS 15 TO 25 KNOTS DIMINISHING TO 10 TO  
20 KNOTS. A CHANCE OF SHOWERS. WAVES BUILDING TO 1 TO 3 FEET,  
THEN SUBSIDING TO CALM TO 2 FEET.    
SUNDAY  
NORTHWEST WINDS 15 TO 25 KNOTS BECOMING WEST 10 TO  
20 KNOTS. WAVES BUILDING TO 1 TO 3 FEET, THEN SUBSIDING TO CALM  
TO 2 FEET.   
  
  
  
LSZ266-122000-  
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-  
401 AM EDT WED AUG 12 2026  
   
EARLY THIS MORNING  
WEST WINDS 5 TO 15 KNOTS. WAVES CALM TO  
2 FEET.    
TODAY  
WEST WINDS 5 TO 15 KNOTS VEERING NORTH LATE. WAVES CALM  
TO 2 FEET.    
TONIGHT  
WEST WINDS 5 TO 15 KNOTS VEERING NORTHWEST LATE. WAVES  
CALM TO 2 FEET.    
THURSDAY  
NORTHWEST WINDS 5 TO 15 KNOTS VEERING NORTH IN THE  
AFTERNOON. WAVES CALM TO 2 FEET.    
THURSDAY NIGHT  
NORTH WINDS 5 TO 15 KNOTS. WAVES CALM TO  
2 FEET.    
FRIDAY  
NORTHEAST WINDS 5 TO 15 KNOTS BACKING NORTH BY MID  
AFTERNOON. WAVES CALM TO 2 FEET.    
FRIDAY NIGHT  
EAST WINDS 5 TO 15 KNOTS VEERING SOUTHEAST AFTER  
MIDNIGHT. WAVES CALM TO 2 FEET.    
SATURDAY  
SOUTHEAST WINDS 15 TO 25 KNOTS BECOMING SOUTH 10 TO  
20 KNOTS. A CHANCE OF SHOWERS. WAVES BUILDING TO 1 TO 3 FEET,  
THEN SUBSIDING TO CALM TO 2 FEET.    
SUNDAY  
NORTHWEST WINDS 15 TO 25 KNOTS DIMINISHING TO 10 TO  
20 KNOTS. WAVES BUILDING TO 2 TO 4 FEET, THEN SUBSIDING TO CALM  
TO 2 FEET.   
  
  
  
LSZ267-122000-  
LAKE SUPERIOR FROM GRAND MARAIS MI TO WHITEFISH POINT MI 5NM OFF  
SHORE TO THE US/CANADIAN BORDER-  
401 AM EDT WED AUG 12 2026  
   
EARLY THIS MORNING  
NORTHWEST WINDS LESS THAN 10 KNOTS. WAVES  
CALM TO 2 FEET.    
TODAY  
NORTHWEST WINDS 5 TO 15 KNOTS. WAVES CALM TO 2 FEET.    
TONIGHT  
NORTHWEST WINDS 5 TO 15 KNOTS BACKING WEST LATE. WAVES  
CALM TO 2 FEET.    
THURSDAY  
NORTHWEST WINDS 5 TO 15 KNOTS. WAVES CALM TO 2 FEET.    
THURSDAY NIGHT  
NORTHWEST WINDS 10 TO 20 KNOTS BECOMING NORTH  
5 TO 15 KNOTS AFTER MIDNIGHT. WAVES CALM TO 2 FEET.    
FRIDAY  
NORTH WINDS 5 TO 15 KNOTS. WAVES CALM TO 2 FEET.    
FRIDAY NIGHT  
NORTH WINDS 5 TO 15 KNOTS VEERING SOUTHEAST AFTER  
MIDNIGHT. WAVES CALM TO 2 FEET.    
SATURDAY  
SOUTHEAST WINDS 10 TO 20 KNOTS. SHOWERS LIKELY. WAVES  
CALM TO 2 FEET.    
SUNDAY  
NORTHWEST WINDS 10 TO 20 KNOTS DIMINISHING TO 5 TO  
15 KNOTS. WAVES BUILDING TO 1 TO 3 FEET, THEN SUBSIDING TO CALM  
TO 2 FEET.   
  
  
  
LSZ261-121400-  
MAFOR 1209/  
SUPERIOR WEST 12700 11600 12400 11200 11100 11800. A CHANCE OF  
SHOWERS OVERNIGHT. WAVES 1 FOOT OR LESS.   
  
SUPERIOR NORTH CENTRAL 12600 12700 12500 11600 11700. WAVES 1  
FOOT OR LESS.   
  
SUPERIOR SOUTH CENTRAL 11700 11600 11700 11100 11200 11300 12400.  
WAVES 1 FOOT OR LESS.   
  
SUPERIOR EAST 15700 11700 11600. WAVES 1 FOOT OR LESS.   
  
  
  
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