997
FZUS63 KMQT 170801
GLFLS
OPEN LAKE FORECAST FOR LAKE SUPERIOR
NATIONAL WEATHER SERVICE MARQUETTE MI
401 AM EDT THU SEP 17 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, A 29.8 INCH LOW OVER THE WESTERN HUDSON BAY IS
EXTENDING WEAK 30.2 INCH TROUGHING OVER LAKE SUPERIOR, WHICH IS
FLANKED BY 30.3 INCH HIGHS OVER QUEBEC AND SOUTHERN MANITOBA
RESPECTIVELY. THROUGHOUT TODAY, THE LOW AND ASSOCATED TROUGH WILL
PUSH EAST AND WEAKEN WHILE THE WESTERN HIGH WILL MOVE OVER THE
ONTARIO/MANITOBA LINE. THIS HIGH BUILDS TO 30.4 INCHES OVER NORTHERN
LAKE SUPERIOR AND NORTHERN ONTARIO BY FRIDAY MORNING AS A 29.9 INCH
LOW DEVELOPS OVER NEBRASKA. BY SATURDAY, THE HIGH WEAKENS TO 30.3
INCHES OVER QUEBEC AS THE LOW EXTENDS OVER IOWA. MEANWHILE, A 30.2
INCH HIGH BUILDS OVER THE CANADIAN PRAIRIE. THROUGHOUT THE WEEKEND,
THE PRAIRIES HIGH WILL BUILD TO 30.3 INCHES AS IT MOVES OVER
NORTHERN ONTARIO AS THE LOW PASSES SOUTH OF THE GREAT LAKES. THE
HIGH BUILDS TO 30.4 INCHES MONDAY AND EXPANDS OVER WESTERN QUEBEC
BEFORE BUILDING TO 30.5 INCHES OVER QUEBEC TUESDAY.
LSZ162-172000-
LAKE SUPERIOR WEST OF A LINE FROM SAXON HARBOR WI TO GRAND
PORTAGE MN BEYOND 5NM-
401 AM EDT THU SEP 17 2026 /301 AM CDT THU SEP 17 2026/
EARLY THIS MORNING
WEST WINDS 5 TO 15 KNOTS. WAVES CALM TO
2 FEET.
TODAY
WEST WINDS 5 TO 15 KNOTS BACKING SOUTHWEST IN THE
AFTERNOON. WAVES CALM TO 2 FEET.
TONIGHT
WEST WINDS 5 TO 15 KNOTS VEERING NORTHEAST AFTER
MIDNIGHT, THEN BECOMING EAST 10 TO 20 KNOTS LATE. WAVES BUILDING
TO 1 TO 3 FEET.
FRIDAY
EAST WINDS 10 TO 20 KNOTS INCREASING TO 15 TO 25 KNOTS
LATE. A SLIGHT CHANCE OF SHOWERS BY MID AFTERNOON. WAVES 1 TO
3 FEET.
FRIDAY NIGHT
EAST WINDS 10 TO 20 KNOTS. A CHANCE OF SHOWERS.
WAVES 1 TO 3 FEET.
SATURDAY
EAST WINDS 15 TO 25 KNOTS BACKING NORTHEAST BY MID
AFTERNOON. WAVES BUILDING TO 2 TO 4 FEET, THEN SUBSIDING TO CALM
TO 2 FEET.
SATURDAY NIGHT
NORTHEAST WINDS 10 TO 20 KNOTS INCREASING TO
15 TO 25 KNOTS AFTER MIDNIGHT. WAVES BUILDING TO 2 TO 4 FEET.
SUNDAY
NORTHEAST GALES TO 35 KNOTS BECOMING EAST 20 TO
30 KNOTS. WAVES BUILDING TO 3 TO 6 FEET OCCASIONALLY TO 8 FEET,
THEN SUBSIDING TO 1 TO 3 FEET.
MONDAY
EAST WINDS 20 TO 30 KNOTS DIMINISHING TO 15 TO
25 KNOTS. WAVES SUBSIDING TO CALM TO 2 FEET, THEN BUILDING TO
2 TO 4 FEET.
LSZ263-172000-
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 THU SEP 17 2026
EARLY THIS MORNING
SOUTHWEST WINDS 5 TO 15 KNOTS. WAVES CALM
TO 2 FEET.
TODAY
WEST WINDS 5 TO 15 KNOTS. WAVES CALM TO 2 FEET.
TONIGHT
WEST WINDS 5 TO 15 KNOTS VEERING NORTHEAST AFTER
MIDNIGHT, THEN VEERING EAST LATE. WAVES BUILDING TO 1 TO 3 FEET.
FRIDAY
EAST WINDS 5 TO 15 KNOTS INCREASING TO 10 TO 20 KNOTS
LATE. A SLIGHT CHANCE OF SHOWERS BY MID AFTERNOON. WAVES
SUBSIDING TO CALM TO 2 FEET, THEN BUILDING TO 1 TO 3 FEET.
FRIDAY NIGHT
EAST WINDS 10 TO 20 KNOTS BECOMING SOUTHEAST 5 TO
15 KNOTS AFTER MIDNIGHT. A CHANCE OF SHOWERS. WAVES SUBSIDING TO
CALM TO 2 FEET.
SATURDAY
EAST WINDS 5 TO 15 KNOTS BECOMING NORTHEAST 10 TO
20 KNOTS BY MID AFTERNOON. WAVES CALM TO 2 FEET.
SATURDAY NIGHT
NORTHEAST WINDS 10 TO 20 KNOTS INCREASING TO
15 TO 25 KNOTS AFTER MIDNIGHT. WAVES BUILDING TO 2 TO 4 FEET.
SUNDAY
NORTHEAST WINDS 20 TO 30 KNOTS VEERING EAST. WAVES
BUILDING TO 3 TO 6 FEET OCCASIONALLY TO 8 FEET, THEN SUBSIDING TO
CALM TO 2 FEET.
MONDAY
EAST WINDS 15 TO 25 KNOTS VEERING SOUTHEAST. WAVES
BUILDING TO 1 TO 3 FEET, THEN SUBSIDING TO CALM TO 2 FEET.
LSZ264-172000-
LAKE SUPERIOR FROM UPPER ENTRANCE TO PORTAGE CANAL TO MANITOU
ISLAND MI 5NM OFF SHORE TO THE US/CANADIAN BORDER-
401 AM EDT THU SEP 17 2026
EARLY THIS MORNING
SOUTHWEST WINDS 5 TO 15 KNOTS. WAVES CALM
TO 2 FEET.
TODAY
WEST WINDS 5 TO 15 KNOTS. WAVES CALM TO 2 FEET.
TONIGHT
NORTH WINDS 5 TO 15 KNOTS VEERING EAST LATE. WAVES
BUILDING TO 1 TO 3 FEET.
FRIDAY
EAST WINDS 5 TO 15 KNOTS. WAVES SUBSIDING TO CALM TO
2 FEET.
FRIDAY NIGHT
SOUTHEAST WINDS 10 TO 20 KNOTS DIMINISHING TO
5 TO 15 KNOTS AFTER MIDNIGHT. WAVES CALM TO 2 FEET.
SATURDAY
SOUTHEAST WINDS 5 TO 15 KNOTS BACKING EAST BY MID
AFTERNOON. WAVES CALM TO 2 FEET.
SATURDAY NIGHT
EAST WINDS 5 TO 15 KNOTS BECOMING NORTH 15 TO
25 KNOTS AFTER MIDNIGHT. WAVES BUILDING TO 1 TO 3 FEET.
SUNDAY
NORTHEAST WINDS 15 TO 25 KNOTS BECOMING EAST 5 TO
15 KNOTS. WAVES BUILDING TO 2 TO 4 FEET, THEN SUBSIDING TO CALM
TO 2 FEET.
MONDAY
EAST WINDS 5 TO 15 KNOTS VEERING SOUTHEAST. WAVES
BUILDING TO 1 TO 3 FEET, THEN SUBSIDING TO CALM TO 2 FEET.
LSZ265-172000-
LAKE SUPERIOR WEST OF LINE FROM MANITOU ISLAND TO MARQUETTE MI
BEYOND 5NM FROM SHORE-
401 AM EDT THU SEP 17 2026
EARLY THIS MORNING
SOUTHWEST WINDS 10 TO 20 KNOTS. A SLIGHT
CHANCE OF SHOWERS. WAVES CALM TO 2 FEET.
TODAY
WEST WINDS 5 TO 15 KNOTS BECOMING NORTHWEST 10 TO
20 KNOTS LATE. WAVES CALM TO 2 FEET.
TONIGHT
NORTHWEST WINDS 10 TO 20 KNOTS VEERING NORTHEAST AFTER
MIDNIGHT. WAVES BUILDING TO 1 TO 3 FEET.
FRIDAY
EAST WINDS 10 TO 20 KNOTS INCREASING TO 15 TO 25 KNOTS
LATE. WAVES 1 TO 3 FEET.
FRIDAY NIGHT
SOUTHEAST WINDS 15 TO 25 KNOTS DIMINISHING TO
10 TO 20 KNOTS AFTER MIDNIGHT. A SLIGHT CHANCE OF SHOWERS AFTER
MIDNIGHT. WAVES SUBSIDING TO CALM TO 2 FEET.
SATURDAY
SOUTHEAST WINDS 15 TO 25 KNOTS BECOMING EAST 10 TO
20 KNOTS BY MID AFTERNOON. WAVES BUILDING TO 1 TO 3 FEET, THEN
SUBSIDING TO CALM TO 2 FEET.
SATURDAY NIGHT
EAST WINDS 10 TO 20 KNOTS BECOMING NORTH 15 TO
25 KNOTS AFTER MIDNIGHT. WAVES BUILDING TO 1 TO 3 FEET.
SUNDAY
NORTHEAST WINDS 20 TO 30 KNOTS BECOMING EAST 15 TO
25 KNOTS. WAVES BUILDING TO 3 TO 5 FEET OCCASIONALLY TO 7 FEET,
THEN SUBSIDING TO 1 TO 3 FEET.
MONDAY
EAST WINDS 15 TO 25 KNOTS BECOMING SOUTHEAST 10 TO
20 KNOTS. WAVES SUBSIDING TO CALM TO 2 FEET.
LSZ266-172000-
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 THU SEP 17 2026
EARLY THIS MORNING
SOUTHWEST WINDS 5 TO 15 KNOTS. A SLIGHT
CHANCE OF SHOWERS. WAVES CALM TO 2 FEET.
TODAY
WEST WINDS 5 TO 15 KNOTS VEERING NORTHWEST IN THE
AFTERNOON. WAVES CALM TO 2 FEET.
TONIGHT
NORTH WINDS 10 TO 20 KNOTS VEERING NORTHEAST LATE.
WAVES BUILDING TO 1 TO 3 FEET.
FRIDAY
EAST WINDS 10 TO 20 KNOTS DIMINISHING TO 5 TO 15 KNOTS
IN THE AFTERNOON. WAVES SUBSIDING TO CALM TO 2 FEET.
FRIDAY NIGHT
EAST WINDS 5 TO 15 KNOTS BECOMING SOUTHEAST 10 TO
20 KNOTS AFTER MIDNIGHT. A SLIGHT CHANCE OF SHOWERS AFTER
MIDNIGHT. WAVES CALM TO 2 FEET.
SATURDAY
SOUTHEAST WINDS 10 TO 20 KNOTS BECOMING EAST 5 TO
15 KNOTS BY MID AFTERNOON. WAVES BUILDING TO 1 TO 3 FEET, THEN
SUBSIDING TO CALM TO 2 FEET.
SATURDAY NIGHT
EAST WINDS 5 TO 15 KNOTS BECOMING NORTH 15 TO
25 KNOTS AFTER MIDNIGHT. WAVES BUILDING TO 1 TO 3 FEET.
SUNDAY
NORTHEAST WINDS 20 TO 30 KNOTS BECOMING EAST 15 TO
25 KNOTS. WAVES BUILDING TO 3 TO 5 FEET OCCASIONALLY TO 7 FEET,
THEN SUBSIDING TO 2 TO 4 FEET.
MONDAY
EAST WINDS 5 TO 15 KNOTS. WAVES SUBSIDING TO CALM TO
2 FEET.
LSZ267-172000-
LAKE SUPERIOR FROM GRAND MARAIS MI TO WHITEFISH POINT MI 5NM OFF
SHORE TO THE US/CANADIAN BORDER-
401 AM EDT THU SEP 17 2026
EARLY THIS MORNING
SOUTH WINDS 5 TO 15 KNOTS. A SLIGHT CHANCE
OF SHOWERS. WAVES CALM TO 2 FEET.
TODAY
SOUTHWEST WINDS 5 TO 15 KNOTS VEERING WEST IN THE
AFTERNOON, THEN BECOMING NORTHWEST 10 TO 20 KNOTS LATE. WAVES
CALM TO 2 FEET.
TONIGHT
NORTHWEST WINDS 10 TO 20 KNOTS VEERING NORTHEAST LATE.
WAVES BUILDING TO 1 TO 3 FEET.
FRIDAY
EAST WINDS 10 TO 20 KNOTS DIMINISHING TO 5 TO 15 KNOTS
IN THE AFTERNOON, THEN BACKING NORTHEAST LATE. WAVES SUBSIDING TO
CALM TO 2 FEET.
FRIDAY NIGHT
EAST WINDS 5 TO 15 KNOTS VEERING SOUTHEAST AFTER
MIDNIGHT. WAVES CALM TO 2 FEET.
SATURDAY
SOUTHEAST WINDS 10 TO 20 KNOTS. WAVES BUILDING TO
1 TO 3 FEET, THEN SUBSIDING TO CALM TO 2 FEET.
SATURDAY NIGHT
EAST WINDS 5 TO 15 KNOTS BACKING NORTH AFTER
MIDNIGHT. WAVES CALM TO 2 FEET.
SUNDAY
NORTH WINDS 10 TO 20 KNOTS BECOMING EAST 15 TO
25 KNOTS. WAVES BUILDING TO 2 TO 4 FEET, THEN SUBSIDING TO 1 TO
3 FEET.
MONDAY
EAST WINDS 5 TO 15 KNOTS INCREASING TO 10 TO 20 KNOTS.
WAVES SUBSIDING TO CALM TO 2 FEET.
LSZ261-171400-
MAFOR 1709/
SUPERIOR WEST 13600 12500 11600 11810 11120. WAVES 2 FEET OR
LESS.
SUPERIOR NORTH CENTRAL 11510 14610 11710 12110. WAVES 1 TO 3
FEET.
SUPERIOR SOUTH CENTRAL 11510 11610 11710 11700 12710 11820 11120.
WAVES 2 FEET OR LESS.
SUPERIOR EAST 11400 11500 11600 11610 12710 11810 11110. WAVES 1
FOOT OR LESS TODAY. WAVES 1 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
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