970
FZUS63 KMQT 151401
GLFLS
OPEN LAKE FORECAST FOR LAKE SUPERIOR
NATIONAL WEATHER SERVICE MARQUETTE MI
1001 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 IS DIGGING INTO WESTERN LAKE SUPERIOR
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-
1001 AM EDT FRI AUG 15 2025 /901 AM CDT FRI AUG 15 2025/
REST OF TODAY
SOUTHWEST WINDS 15 TO 25 KNOTS DIMINISHING TO
5 TO 15 KNOTS. A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS BY
MID AFTERNOON. WAVES 1 TO 3 FEET 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. A SLIGHT CHANCE OF SHOWERS. 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-
1001 AM EDT FRI AUG 15 2025
REST OF TODAY
SOUTHWEST WINDS 10 TO 20 KNOTS. A SLIGHT CHANCE
OF SHOWERS AND THUNDERSTORMS BY MID AFTERNOON. WAVES 2 TO 4 FEET
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. A SLIGHT CHANCE OF SHOWERS
BY MID AFTERNOON. 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-
1001 AM EDT FRI AUG 15 2025
REST OF TODAY
SOUTHWEST WINDS 10 TO 20 KNOTS. A SLIGHT CHANCE
OF SHOWERS AND THUNDERSTORMS. WAVES 2 TO 4 FEET 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-
1001 AM EDT FRI AUG 15 2025
REST OF TODAY
SOUTH WINDS 10 TO 20 KNOTS BACKING EAST LATE. A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS BY MID AFTERNOON.
WAVES CALM TO 2 FEET.
TONIGHT
SOUTHWEST WINDS 5 TO 15 KNOTS VEERING NORTHWEST LATE.
A CHANCE OF SHOWERS AND THUNDERSTORMS. PATCHY FOG AFTER MIDNIGHT.
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-
1001 AM EDT FRI AUG 15 2025
REST OF TODAY
SOUTH WINDS 15 TO 25 KNOTS DIMINISHING TO 10 TO
20 KNOTS IN THE AFTERNOON. A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS BY MID AFTERNOON. WAVES 2 TO 4 FEET 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. PATCHY FOG AFTER MIDNIGHT. WAVES
SUBSIDING TO CALM TO 2 FEET.
SATURDAY
NORTH WINDS 10 TO 20 KNOTS. PATCHY FOG THROUGH EARLY
AFTERNOON. 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-
1001 AM EDT FRI AUG 15 2025
REST OF TODAY
SOUTH WINDS 15 TO 25 KNOTS DIMINISHING TO 10 TO
20 KNOTS LATE. WAVES 1 TO 3 FEET 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. PATCHY FOG AFTER MIDNIGHT. 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. PATCHY FOG THROUGH EARLY AFTERNOON. 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.
LSZ261-152000-
MAFOR 1515/
SUPERIOR WEST 11520 13510 11600 11700 11110 11120. A CHANCE OF
SHOWERS AND THUNDERSTORMS OVERNIGHT AND SATURDAY MORNING. WAVES 1
TO 3 FEET THIS AFTERNOON. WAVES 2 FEET OR LESS TONIGHT AND
SATURDAY MORNING.
SUPERIOR NORTH CENTRAL 13520 12510 11710 12810. A CHANCE OF
THUNDERSTORMS SATURDAY MORNING. WAVES 2 TO 4 FEET THIS AFTERNOON.
WAVES 1 TO 3 FEET TONIGHT AND SATURDAY MORNING.
SUPERIOR SOUTH CENTRAL 11420 11410 11310 12510 11600 11710 11810.
A CHANCE OF SHOWERS AND THUNDERSTORMS OVERNIGHT. A CHANCE OF
SHOWERS SATURDAY MORNING. WAVES 1 TO 3 FEET THIS AFTERNOON. WAVES
2 FEET OR LESS TONIGHT AND SATURDAY MORNING.
SUPERIOR EAST 11430 13420 11520 11510 11610 11700. A CHANCE OF
SHOWERS AND THUNDERSTORMS OVERNIGHT AND SATURDAY MORNING. WAVES 2
TO 4 FEET SUBSIDING TO 1 TO 3 FEET THIS AFTERNOON. WAVES 1 TO 3
FEET TONIGHT AND SATURDAY MORNING.
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
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