318
FZUS63 KMQT 152001
GLFLS
OPEN LAKE FORECAST FOR LAKE SUPERIOR
NATIONAL WEATHER SERVICE MARQUETTE MI
401 PM 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. MONDAY INTO TUESDAY, A 29.9 INCH
LOW MAY MOVE THROUGH WISCONSIN INTO LOWER MICHIGAN WHILE 30.2. INCH
RIDGING STRETCHES ACROSS QUEBEC, ONTARIO, AND MANITOBA.
LSZ162-160800-
LAKE SUPERIOR WEST OF A LINE FROM SAXON HARBOR WI TO GRAND
PORTAGE MN BEYOND 5NM-
401 PM EDT FRI AUG 15 2025 /301 PM CDT FRI AUG 15 2025/
LATE THIS AFTERNOON
SOUTHWEST WINDS 10 TO 20 KNOTS. A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS. WAVES CALM TO 2 FEET.
TONIGHT
SOUTHWEST WINDS 5 TO 15 KNOTS VEERING WEST AFTER
MIDNIGHT, THEN VEERING NORTHEAST LATE. A CHANCE OF SHOWERS AND A
SLIGHT CHANCE OF THUNDERSTORMS. WAVES CALM TO 2 FEET.
SATURDAY
NORTHEAST WINDS 10 TO 20 KNOTS VEERING EAST LATE. A
CHANCE OF SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS. WAVES
BUILDING TO 2 TO 4 FEET.
SATURDAY NIGHT
NORTHEAST WINDS 10 TO 20 KNOTS INCREASING TO
15 TO 25 KNOTS AFTER MIDNIGHT. WAVES BUILDING TO 3 TO 5 FEET
OCCASIONALLY TO 7 FEET, THEN SUBSIDING TO 2 TO 4 FEET.
SUNDAY
EAST WINDS 20 TO 30 KNOTS. A SLIGHT CHANCE OF SHOWERS.
WAVES BUILDING TO 4 TO 8 FEET OCCASIONALLY TO 10 FEET.
SUNDAY NIGHT
EAST WINDS 20 TO 30 KNOTS DIMINISHING TO 15 TO
25 KNOTS AFTER MIDNIGHT. A CHANCE OF SHOWERS. WAVES SUBSIDING TO
2 TO 4 FEET.
MONDAY
EAST WINDS 10 TO 20 KNOTS BECOMING NORTHEAST 15 TO
25 KNOTS BY MID AFTERNOON. A CHANCE OF SHOWERS. WAVES 2 TO
4 FEET.
MONDAY NIGHT
NORTHEAST WINDS 10 TO 20 KNOTS. WAVES SUBSIDING
TO 1 TO 3 FEET.
TUESDAY
NORTHEAST WINDS 10 TO 20 KNOTS DIMINISHING TO 5 TO
15 KNOTS. WAVES SUBSIDING TO CALM TO 2 FEET.
WEDNESDAY
SOUTH WINDS 5 TO 15 KNOTS BACKING EAST. WAVES CALM
TO 2 FEET.
LSZ263-160800-
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 PM EDT FRI AUG 15 2025
LATE THIS AFTERNOON
SOUTHWEST WINDS 10 TO 20 KNOTS. A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS. WAVES 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 10 TO 20 KNOTS. A CHANCE OF SHOWERS
AND A SLIGHT CHANCE OF THUNDERSTORMS. WAVES BUILDING TO 2 TO
4 FEET.
SATURDAY NIGHT
NORTHEAST WINDS 10 TO 20 KNOTS INCREASING TO
15 TO 25 KNOTS AFTER MIDNIGHT. WAVES BUILDING TO 3 TO 5 FEET
OCCASIONALLY TO 7 FEET, THEN SUBSIDING TO 2 TO 4 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 10 TO 20 KNOTS. A CHANCE OF SHOWERS. WAVES
BUILDING TO 3 TO 5 FEET OCCASIONALLY TO 7 FEET, THEN SUBSIDING TO
2 TO 4 FEET.
MONDAY NIGHT
EAST WINDS 10 TO 20 KNOTS DIMINISHING TO 5 TO
15 KNOTS AFTER MIDNIGHT. WAVES SUBSIDING TO 1 TO 3 FEET.
TUESDAY
EAST WINDS 5 TO 15 KNOTS BACKING NORTHEAST. WAVES
SUBSIDING TO CALM TO 2 FEET.
WEDNESDAY
NORTH WINDS 5 TO 15 KNOTS VEERING SOUTH. WAVES CALM
TO 2 FEET.
LSZ264-160800-
LAKE SUPERIOR FROM UPPER ENTRANCE TO PORTAGE CANAL TO MANITOU
ISLAND MI 5NM OFF SHORE TO THE US/CANADIAN BORDER-
401 PM EDT FRI AUG 15 2025
LATE THIS AFTERNOON
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
NORTHEAST WINDS 5 TO 15 KNOTS BECOMING NORTH 10 TO
20 KNOTS IN THE AFTERNOON. A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. WAVES BUILDING TO 1 TO 3 FEET, THEN SUBSIDING TO
CALM TO 2 FEET.
SATURDAY NIGHT
NORTH WINDS 10 TO 20 KNOTS BECOMING NORTHEAST
15 TO 25 KNOTS 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. WAVES SUBSIDING TO
1 TO 3 FEET.
MONDAY
EAST WINDS 10 TO 20 KNOTS INCREASING TO 15 TO 25 KNOTS
BY MID AFTERNOON. A CHANCE OF SHOWERS. WAVES BUILDING TO 3 TO
5 FEET OCCASIONALLY TO 7 FEET, THEN SUBSIDING TO 2 TO 4 FEET.
MONDAY NIGHT
EAST WINDS 10 TO 20 KNOTS DIMINISHING TO 5 TO
15 KNOTS AFTER MIDNIGHT. WAVES SUBSIDING TO 1 TO 3 FEET.
TUESDAY
EAST WINDS 5 TO 15 KNOTS. WAVES SUBSIDING TO CALM TO
2 FEET.
WEDNESDAY
NORTHWEST WINDS 5 TO 15 KNOTS BACKING SOUTHWEST.
WAVES CALM TO 2 FEET.
LSZ265-160800-
LAKE SUPERIOR WEST OF LINE FROM MANITOU ISLAND TO MARQUETTE MI
BEYOND 5NM FROM SHORE-
401 PM EDT FRI AUG 15 2025
LATE THIS AFTERNOON
EAST WINDS 5 TO 15 KNOTS. A SLIGHT CHANCE
OF SHOWERS AND THUNDERSTORMS. WAVES CALM TO 2 FEET.
TONIGHT
SOUTH WINDS 5 TO 15 KNOTS VEERING WEST AFTER MIDNIGHT.
A CHANCE OF SHOWERS AND THUNDERSTORMS. WAVES CALM TO 2 FEET.
SATURDAY
NORTH WINDS 10 TO 20 KNOTS VEERING NORTHEAST IN THE
AFTERNOON, THEN BECOMING NORTH 15 TO 25 KNOTS LATE. A CHANCE OF
SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS. WAVES BUILDING TO
1 TO 3 FEET.
SATURDAY NIGHT
NORTH WINDS 10 TO 20 KNOTS BECOMING NORTHEAST
15 TO 25 KNOTS AFTER MIDNIGHT. WAVES SUBSIDING TO CALM TO 2 FEET,
THEN BUILDING TO 3 TO 5 FEET OCCASIONALLY TO 7 FEET.
SUNDAY
EAST WINDS 15 TO 25 KNOTS. WAVES SUBSIDING TO 1 TO
3 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
SOUTHEAST WINDS 15 TO 25 KNOTS BACKING EAST BY MID
AFTERNOON. A CHANCE OF SHOWERS. WAVES BUILDING TO 2 TO 4 FEET,
THEN SUBSIDING TO 1 TO 3 FEET.
MONDAY NIGHT
EAST WINDS 10 TO 20 KNOTS. WAVES SUBSIDING TO
CALM TO 2 FEET.
TUESDAY
EAST WINDS 10 TO 20 KNOTS DIMINISHING TO 5 TO
15 KNOTS. WAVES CALM TO 2 FEET.
WEDNESDAY
NORTH WINDS 5 TO 15 KNOTS VEERING SOUTH. WAVES CALM
TO 2 FEET.
LSZ266-160800-
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 PM EDT FRI AUG 15 2025
LATE THIS AFTERNOON
SOUTH WINDS 10 TO 20 KNOTS. A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS. WAVES 1 TO 3 FEET.
TONIGHT
SOUTH WINDS 10 TO 20 KNOTS BECOMING SOUTHWEST 5 TO
15 KNOTS AFTER MIDNIGHT, THEN VEERING WEST 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. A
SLIGHT CHANCE OF THUNDERSTORMS BY MID AFTERNOON. 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 1 TO 3 FEET.
SUNDAY NIGHT
EAST WINDS 10 TO 20 KNOTS VEERING SOUTHEAST AFTER
MIDNIGHT. WAVES SUBSIDING TO CALM TO 2 FEET, THEN BUILDING TO
2 TO 4 FEET.
MONDAY
SOUTHEAST WINDS 15 TO 25 KNOTS BACKING EAST BY MID
AFTERNOON. A CHANCE OF SHOWERS. WAVES 2 TO 4 FEET.
MONDAY NIGHT
EAST WINDS 10 TO 20 KNOTS. 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.
WEDNESDAY
NORTH WINDS 5 TO 15 KNOTS. WAVES CALM TO 2 FEET.
LSZ267-160800-
LAKE SUPERIOR FROM GRAND MARAIS MI TO WHITEFISH POINT MI 5NM OFF
SHORE TO THE US/CANADIAN BORDER-
401 PM EDT FRI AUG 15 2025
LATE THIS AFTERNOON
SOUTH WINDS 10 TO 20 KNOTS. WAVES CALM TO
2 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
BUILDING TO 1 TO 3 FEET, THEN SUBSIDING TO CALM TO 2 FEET.
SATURDAY
WEST WINDS 5 TO 15 KNOTS VEERING NORTHWEST IN THE
AFTERNOON, THEN BECOMING NORTH 10 TO 20 KNOTS LATE. PATCHY FOG
THROUGH EARLY AFTERNOON. A CHANCE OF SHOWERS AND A SLIGHT CHANCE
OF THUNDERSTORMS. WAVES CALM TO 2 FEET.
SATURDAY NIGHT
NORTH WINDS 10 TO 20 KNOTS BECOMING NORTHEAST
15 TO 25 KNOTS AFTER MIDNIGHT. A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS THROUGH 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 BY MID
AFTERNOON. A CHANCE OF SHOWERS. WAVES SUBSIDING TO 1 TO 3 FEET.
MONDAY NIGHT
EAST WINDS 10 TO 20 KNOTS. A CHANCE OF SHOWERS.
WAVES SUBSIDING TO CALM TO 2 FEET.
TUESDAY
EAST WINDS 10 TO 20 KNOTS BACKING NORTHEAST. WAVES
CALM TO 2 FEET.
WEDNESDAY
NORTH WINDS 10 TO 20 KNOTS DIMINISHING TO 5 TO
15 KNOTS. WAVES CALM TO 2 FEET.
LSZ261-160200-
MAFOR 1521/
SUPERIOR WEST 11510 11500 11600 11700 11110 13120. A CHANCE OF
SHOWERS AND THUNDERSTORMS OVERNIGHT. A CHANCE OF SHOWERS
SATURDAY. WAVES 2 FEET OR LESS TONIGHT. WAVES 1 TO 3 FEET
BUILDING TO 2 TO 4 FEET SATURDAY.
SUPERIOR NORTH CENTRAL 11520 12510 11710 11810 12110 11820. WAVES
2 TO 4 FEET SUBSIDING TO 1 TO 3 FEET TONIGHT. WAVES 1 TO 2 FEET
SATURDAY.
SUPERIOR SOUTH CENTRAL 11310 11400 11500 11600 11700 11810 11110
11820. A CHANCE OF SHOWERS AND THUNDERSTORMS OVERNIGHT. A CHANCE
OF SHOWERS SATURDAY. WAVES 2 FEET OR LESS.
SUPERIOR EAST 12420 12510 11600 11700 11800 11810. A CHANCE OF
SHOWERS AND THUNDERSTORMS OVERNIGHT. A CHANCE OF SHOWERS AND
THUNDERSTORMS SATURDAY MORNING, THEN A CHANCE OF SHOWERS SATURDAY
AFTERNOON. WAVES 1 TO 3 FEET.
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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