352  
FZUS63 KMQT 150801  
GLFLS  
 
OPEN LAKE FORECAST FOR LAKE SUPERIOR  
NATIONAL WEATHER SERVICE MARQUETTE MI  
401 AM EDT FRI AUG 15 2025  
 
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  
 
WEAK TROUGHING OF 29.9 INCHES BUILDS IN FROM THE WEST TODAY THANKS  
TO A 29.5 INCH LOW PRESSURE MOVING FROM NORTHERN MANITOBA INTO  
ONTARIO ALONG HUDSON BAY. TROUGHING WEAKENS TONIGHT AS A 30.2 INCH  
HIGH BUILDS ACROSS MANITOBA. THIS HIGH PRESSES THROUGH ONTARIO AT  
30.3 INCHES SUNDAY INTO MONDAY WHILE MAINTAINING 30.2 INCH RIDGING  
OVER LAKE SUPERIOR. AS THE PARENT HIGH RETROGRADES FROM QUEBEC INTO  
HUDSON BAY, EXPECT REMNANT 30.1 INCH RIDGING TO REMAIN OVER LAKE  
SUPERIOR THROUGH THE MIDDLE OF NEXT WEEK.  
 
LSZ162-152000-  
LAKE SUPERIOR WEST OF A LINE FROM SAXON HARBOR WI TO GRAND  
PORTAGE MN BEYOND 5NM-  
401 AM EDT FRI AUG 15 2025 /301 AM CDT FRI AUG 15 2025/  
   
EARLY THIS MORNING  
SOUTHWEST WINDS 10 TO 20 KNOTS. A CHANCE OF  
SHOWERS AND THUNDERSTORMS. WAVES 1 TO 3 FEET.    
TODAY  
SOUTHWEST 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  
SOUTHWEST WINDS 5 TO 15 KNOTS VEERING NORTHWEST AFTER  
MIDNIGHT, THEN BECOMING NORTH 10 TO 20 KNOTS LATE. A CHANCE OF  
SHOWERS AND THUNDERSTORMS. WAVES CALM TO 2 FEET.    
SATURDAY  
NORTHEAST WINDS 10 TO 20 KNOTS VEERING EAST LATE. A  
SLIGHT CHANCE OF THUNDERSTORMS THROUGH EARLY AFTERNOON. A CHANCE  
OF SHOWERS. WAVES BUILDING TO 2 TO 4 FEET.    
SATURDAY NIGHT  
EAST WINDS 10 TO 20 KNOTS INCREASING TO 15 TO  
25 KNOTS AFTER MIDNIGHT. A SLIGHT CHANCE OF SHOWERS AFTER  
MIDNIGHT. WAVES BUILDING TO 3 TO 6 FEET OCCASIONALLY TO 8 FEET.    
SUNDAY  
EAST WINDS 15 TO 25 KNOTS INCREASING TO 20 TO 30 KNOTS  
BY MID AFTERNOON. WAVES BUILDING TO 4 TO 7 FEET OCCASIONALLY TO  
9 FEET.    
SUNDAY NIGHT  
EAST WINDS 15 TO 25 KNOTS. A CHANCE OF SHOWERS.  
WAVES SUBSIDING TO 2 TO 4 FEET.    
MONDAY  
EAST WINDS 15 TO 25 KNOTS BECOMING NORTHEAST 10 TO  
20 KNOTS. A CHANCE OF SHOWERS. WAVES SUBSIDING TO 1 TO 3 FEET.    
TUESDAY  
NORTHEAST WINDS 10 TO 20 KNOTS BECOMING NORTH 5 TO  
15 KNOTS. WAVES SUBSIDING TO CALM TO 2 FEET.  
 
 
 
LSZ263-152000-  
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 FRI AUG 15 2025  
   
EARLY THIS MORNING  
SOUTH WINDS 10 TO 20 KNOTS. A CHANCE OF  
SHOWERS AND THUNDERSTORMS. WAVES 2 TO 4 FEET.    
TODAY  
SOUTHWEST WINDS 10 TO 20 KNOTS. A CHANCE OF SHOWERS AND  
THUNDERSTORMS. WAVES SUBSIDING TO 1 TO 3 FEET.    
TONIGHT  
SOUTHWEST WINDS 5 TO 15 KNOTS VEERING WEST AFTER  
MIDNIGHT, THEN VEERING NORTH LATE. A CHANCE OF SHOWERS AND  
THUNDERSTORMS. WAVES SUBSIDING TO CALM TO 2 FEET.    
SATURDAY  
NORTHEAST WINDS 5 TO 15 KNOTS INCREASING TO 10 TO  
20 KNOTS IN THE AFTERNOON. A CHANCE OF SHOWERS AND A SLIGHT  
CHANCE OF THUNDERSTORMS. WAVES BUILDING TO 2 TO 4 FEET.    
SATURDAY NIGHT  
NORTHEAST WINDS 15 TO 25 KNOTS VEERING EAST  
AFTER MIDNIGHT. A SLIGHT CHANCE OF SHOWERS. WAVES BUILDING TO  
3 TO 6 FEET OCCASIONALLY TO 8 FEET.    
SUNDAY  
EAST WINDS 15 TO 25 KNOTS. WAVES BUILDING TO 4 TO  
7 FEET OCCASIONALLY TO 9 FEET, THEN SUBSIDING TO 3 TO 6 FEET  
OCCASIONALLY TO 8 FEET.    
SUNDAY NIGHT  
EAST WINDS 15 TO 25 KNOTS DIMINISHING TO 10 TO  
20 KNOTS AFTER MIDNIGHT. A CHANCE OF SHOWERS. WAVES SUBSIDING TO  
2 TO 4 FEET.    
MONDAY  
EAST WINDS 15 TO 25 KNOTS DIMINISHING TO 10 TO  
20 KNOTS. A CHANCE OF SHOWERS. WAVES BUILDING TO 3 TO 5 FEET  
OCCASIONALLY TO 7 FEET, THEN SUBSIDING TO 1 TO 3 FEET.    
TUESDAY  
EAST WINDS 5 TO 15 KNOTS. WAVES SUBSIDING TO CALM TO  
2 FEET.  
 
 
 
LSZ264-152000-  
LAKE SUPERIOR FROM UPPER ENTRANCE TO PORTAGE CANAL TO MANITOU  
ISLAND MI 5NM OFF SHORE TO THE US/CANADIAN BORDER-  
401 AM EDT FRI AUG 15 2025  
   
EARLY THIS MORNING  
SOUTH WINDS 10 TO 20 KNOTS. A SLIGHT CHANCE  
OF SHOWERS AND THUNDERSTORMS. WAVES 2 TO 4 FEET.    
TODAY  
SOUTH WINDS 10 TO 20 KNOTS VEERING SOUTHWEST IN THE  
AFTERNOON. A CHANCE OF SHOWERS AND A SLIGHT CHANCE OF  
THUNDERSTORMS THROUGH EARLY AFTERNOON. WAVES SUBSIDING TO 1 TO  
3 FEET.    
TONIGHT  
SOUTHWEST WINDS 5 TO 15 KNOTS VEERING WEST AFTER  
MIDNIGHT, THEN VEERING NORTH LATE. A SLIGHT CHANCE OF SHOWERS AND  
THUNDERSTORMS. WAVES SUBSIDING TO CALM TO 2 FEET.    
SATURDAY  
NORTH WINDS 5 TO 15 KNOTS. A SLIGHT CHANCE OF SHOWERS  
THROUGH EARLY AFTERNOON. WAVES BUILDING TO 1 TO 3 FEET, THEN  
SUBSIDING TO CALM TO 2 FEET.    
SATURDAY NIGHT  
NORTH WINDS 15 TO 25 KNOTS VEERING NORTHEAST  
AFTER MIDNIGHT. WAVES BUILDING TO 3 TO 6 FEET OCCASIONALLY TO  
8 FEET.    
SUNDAY  
EAST WINDS 15 TO 25 KNOTS DIMINISHING TO 10 TO 20 KNOTS  
BY MID AFTERNOON. WAVES SUBSIDING TO 2 TO 4 FEET.    
SUNDAY NIGHT  
EAST WINDS 5 TO 15 KNOTS INCREASING TO 10 TO  
20 KNOTS AFTER MIDNIGHT. A CHANCE OF SHOWERS AFTER MIDNIGHT.  
WAVES SUBSIDING TO CALM TO 2 FEET, THEN BUILDING TO 2 TO 4 FEET.    
MONDAY  
EAST WINDS 15 TO 25 KNOTS DIMINISHING TO 10 TO  
20 KNOTS. A CHANCE OF SHOWERS. WAVES BUILDING TO 3 TO 5 FEET  
OCCASIONALLY TO 7 FEET, THEN SUBSIDING TO 1 TO 3 FEET.    
TUESDAY  
EAST WINDS 5 TO 15 KNOTS BACKING NORTHWEST. WAVES  
SUBSIDING TO CALM TO 2 FEET.  
 
 
 
LSZ265-152000-  
LAKE SUPERIOR WEST OF LINE FROM MANITOU ISLAND TO MARQUETTE MI  
BEYOND 5NM FROM SHORE-  
401 AM EDT FRI AUG 15 2025  
   
EARLY THIS MORNING  
SOUTH WINDS 10 TO 20 KNOTS. A SLIGHT CHANCE  
OF SHOWERS AND THUNDERSTORMS. WAVES 1 TO 3 FEET.    
TODAY  
SOUTH WINDS 10 TO 20 KNOTS BACKING EAST LATE. A SLIGHT  
CHANCE OF SHOWERS AND THUNDERSTORMS. WAVES SUBSIDING TO CALM TO  
2 FEET.    
TONIGHT  
SOUTHWEST WINDS 5 TO 15 KNOTS VEERING NORTHWEST LATE.  
A CHANCE OF SHOWERS AND THUNDERSTORMS. WAVES CALM TO 2 FEET.    
SATURDAY  
NORTH WINDS 10 TO 20 KNOTS. A SLIGHT CHANCE OF  
THUNDERSTORMS THROUGH EARLY AFTERNOON. A CHANCE OF SHOWERS. WAVES  
BUILDING TO 1 TO 3 FEET.    
SATURDAY NIGHT  
NORTH WINDS 15 TO 25 KNOTS VEERING NORTHEAST  
AFTER MIDNIGHT. WAVES BUILDING TO 3 TO 6 FEET OCCASIONALLY TO  
8 FEET.    
SUNDAY  
EAST WINDS 15 TO 25 KNOTS. WAVES SUBSIDING TO 2 TO  
4 FEET.    
SUNDAY NIGHT  
EAST WINDS 10 TO 20 KNOTS VEERING SOUTHEAST AFTER  
MIDNIGHT. A CHANCE OF SHOWERS. WAVES SUBSIDING TO CALM TO 2 FEET,  
THEN BUILDING TO 1 TO 3 FEET.    
MONDAY  
EAST WINDS 15 TO 25 KNOTS DIMINISHING TO 10 TO  
20 KNOTS. A CHANCE OF SHOWERS. WAVES BUILDING TO 2 TO 4 FEET,  
THEN SUBSIDING TO 1 TO 3 FEET.    
TUESDAY  
EAST WINDS 10 TO 20 KNOTS BECOMING NORTH 5 TO  
15 KNOTS. WAVES SUBSIDING TO CALM TO 2 FEET.  
 
 
 
LSZ266-152000-  
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 FRI AUG 15 2025  
   
EARLY THIS MORNING  
SOUTH WINDS 15 TO 25 KNOTS. A SLIGHT CHANCE  
OF SHOWERS AND THUNDERSTORMS. WAVES 3 TO 5 FEET OCCASIONALLY TO  
7 FEET SUBSIDING TO 2 TO 4 FEET.    
TODAY  
SOUTH WINDS 15 TO 25 KNOTS DIMINISHING TO 10 TO 20 KNOTS  
IN THE AFTERNOON. A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS  
THROUGH EARLY AFTERNOON. WAVES SUBSIDING TO 1 TO 3 FEET.    
TONIGHT  
SOUTH WINDS 10 TO 20 KNOTS VEERING SOUTHWEST AFTER  
MIDNIGHT, THEN BECOMING WEST 5 TO 15 KNOTS LATE. A CHANCE OF  
SHOWERS AND THUNDERSTORMS. WAVES SUBSIDING TO CALM TO 2 FEET.    
SATURDAY  
NORTH WINDS 10 TO 20 KNOTS. A CHANCE OF SHOWERS AND A  
SLIGHT CHANCE OF THUNDERSTORMS. WAVES BUILDING TO 1 TO 3 FEET.    
SATURDAY NIGHT  
NORTH WINDS 15 TO 25 KNOTS VEERING NORTHEAST  
AFTER MIDNIGHT. WAVES BUILDING TO 3 TO 6 FEET OCCASIONALLY TO  
8 FEET.    
SUNDAY  
NORTHEAST WINDS 15 TO 25 KNOTS DIMINISHING TO 10 TO  
20 KNOTS BY MID AFTERNOON. WAVES SUBSIDING TO 2 TO 4 FEET.    
SUNDAY NIGHT  
EAST WINDS 10 TO 20 KNOTS VEERING SOUTHEAST AFTER  
MIDNIGHT. A CHANCE OF SHOWERS AFTER MIDNIGHT. WAVES SUBSIDING TO  
CALM TO 2 FEET, THEN BUILDING TO 2 TO 4 FEET.    
MONDAY  
EAST WINDS 15 TO 25 KNOTS DIMINISHING TO 10 TO  
20 KNOTS. A CHANCE OF SHOWERS. WAVES SUBSIDING TO 1 TO 3 FEET.    
TUESDAY  
EAST WINDS 10 TO 20 KNOTS BECOMING NORTHEAST 5 TO  
15 KNOTS. WAVES SUBSIDING TO CALM TO 2 FEET.  
 
 
 
LSZ267-152000-  
LAKE SUPERIOR FROM GRAND MARAIS MI TO WHITEFISH POINT MI 5NM OFF  
SHORE TO THE US/CANADIAN BORDER-  
401 AM EDT FRI AUG 15 2025  
   
EARLY THIS MORNING  
SOUTH WINDS 15 TO 25 KNOTS. WAVES 1 TO  
3 FEET.    
TODAY  
SOUTH WINDS 15 TO 25 KNOTS DIMINISHING TO 10 TO 20 KNOTS  
LATE. WAVES SUBSIDING TO CALM TO 2 FEET.    
TONIGHT  
SOUTH WINDS 15 TO 25 KNOTS BECOMING SOUTHWEST 10 TO  
20 KNOTS AFTER MIDNIGHT, THEN VEERING WEST LATE. A CHANCE OF  
SHOWERS AND THUNDERSTORMS. WAVES BUILDING TO 1 TO 3 FEET, THEN  
SUBSIDING TO CALM TO 2 FEET.    
SATURDAY  
NORTHWEST WINDS 5 TO 15 KNOTS BECOMING NORTH 10 TO  
20 KNOTS LATE. A CHANCE OF SHOWERS AND A SLIGHT CHANCE OF  
THUNDERSTORMS. WAVES BUILDING TO 1 TO 3 FEET.    
SATURDAY NIGHT  
NORTH WINDS 15 TO 25 KNOTS VEERING NORTHEAST  
AFTER MIDNIGHT. WAVES BUILDING TO 3 TO 5 FEET OCCASIONALLY TO  
7 FEET.    
SUNDAY  
NORTHEAST WINDS 10 TO 20 KNOTS. WAVES SUBSIDING TO CALM  
TO 2 FEET.    
SUNDAY NIGHT  
EAST WINDS 10 TO 20 KNOTS BECOMING SOUTHEAST  
15 TO 25 KNOTS AFTER MIDNIGHT. WAVES BUILDING TO 2 TO 4 FEET.    
MONDAY  
SOUTHEAST WINDS 15 TO 25 KNOTS BACKING EAST. A CHANCE  
OF SHOWERS. WAVES SUBSIDING TO 1 TO 3 FEET.    
TUESDAY  
EAST WINDS 10 TO 20 KNOTS BACKING NORTHEAST. WAVES  
SUBSIDING TO CALM TO 2 FEET.  
 
 
 
LSZ261-151400-  
MAFOR 1509/  
SUPERIOR WEST 13520 13510 11600 11700. A CHANCE OF SHOWERS AND  
THUNDERSTORMS THIS MORNING AND OVERNIGHT. WAVES 1 TO 3 FEET  
TODAY. WAVES 2 FEET OR LESS TONIGHT.  
 
SUPERIOR NORTH CENTRAL 11420 11430 13520 12510 11710. A CHANCE OF  
SHOWERS AND THUNDERSTORMS EARLY THIS MORNING. WAVES 2 TO 4 FEET  
TODAY. WAVES 1 TO 3 FEET TONIGHT.  
 
SUPERIOR SOUTH CENTRAL 13420 11410 11310 12510 11600. A CHANCE OF  
SHOWERS AND THUNDERSTORMS OVERNIGHT. WAVES 1 TO 3 FEET TODAY.  
WAVES 2 FEET OR LESS TONIGHT.  
 
SUPERIOR EAST 11420 12430 13420 11520 11510. A CHANCE OF SHOWERS  
AND THUNDERSTORMS OVERNIGHT. WAVES 2 TO 4 FEET SUBSIDING TO 1 TO  
3 FEET TODAY. WAVES 2 TO 3 FEET TONIGHT.  
 
 
 
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  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab MI Page
Main Text Page