Marine Weather, NWS WFO Duluth, MN

Nearshore Forecast

692
FZUS53 KDLH 210309
NSHDLH

Nearshore Marine Forecast
National Weather Service Duluth MN
1009 PM CDT Tue May 20 2025

For waters within five 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.

LSZ140-141-211015-
Grand Portage to Grand Marais MN-
Grand Marais to Taconite Harbor MN-
1009 PM CDT Tue May 20 2025

...GALE WARNING IN EFFECT UNTIL 10 AM CDT WEDNESDAY...

.REST OF TONIGHT...Northeast wind 20 to 25 knots with gales to
around 35 knots. Cloudy. Waves 5 to 8 feet. Waves occasionally to
10 feet.
.WEDNESDAY...Northeast wind 20 to 25 knots. Gusts up to 35 knots
decreasing to 25 knots. Mostly cloudy. Waves 5 to 8 feet. Waves
occasionally to 10 feet.
.WEDNESDAY NIGHT...Northeast wind 10 to 15 knots. Gusts up to
20 knots in the late evening and overnight. Mostly cloudy in the
evening then clearing. Waves 2 to 4 feet subsiding to 1 to 3 feet
after midnight. A small craft advisory may be needed.
.THURSDAY...Northeast wind 10 to 15 knots. Gusts up to 20 knots
in the morning. Mostly sunny. Waves 1 to 2 feet.

$$

LSZ143-211015-
Silver Bay Harbor to Two Harbors MN-
1009 PM CDT Tue May 20 2025

...GALE WARNING IN EFFECT THROUGH WEDNESDAY AFTERNOON...

.REST OF TONIGHT...Northeast wind 20 to 25 knots. Gusts up to
30 knots increasing to 35 knots after midnight. Chance of rain
showers in the late evening and early morning, then slight chance
of rain showers toward daybreak. Waves 7 to 10 feet. Waves
occasionally to 13 feet.
.WEDNESDAY...Northeast wind 20 to 25 knots. Gusts up to 35 knots
decreasing to 30 knots late in the afternoon. Cloudy. Waves 6 to
9 feet. Waves occasionally to 12 feet.
.WEDNESDAY NIGHT...Northeast wind 10 to 15 knots. Gusts up to
25 knots early in the evening. Mostly cloudy in the evening then
becoming partly cloudy. Waves 4 to 6 feet subsiding to 1 to
2 feet. Waves occasionally to 8 feet. A small craft advisory may
be needed.
.THURSDAY...North wind 5 to 10 knots becoming east in the
afternoon. Mostly sunny. Waves 1 to 2 feet.

$$

LSZ142-211015-
Taconite Harbor to Silver Bay Harbor MN-
1009 PM CDT Tue May 20 2025

...GALE WARNING IN EFFECT UNTIL 10 AM CDT WEDNESDAY...

.REST OF TONIGHT...Northeast wind 20 to 25 knots with gales to
around 35 knots. Slight chance of rain showers in the late
evening and early morning. Waves 7 to 10 feet. Waves occasionally
to 12 feet.
.WEDNESDAY...Northeast wind 20 to 25 knots. Gusts up to 35 knots
decreasing to 25 knots. Mostly cloudy. Waves 5 to 8 feet. Waves
occasionally to 11 feet.
.WEDNESDAY NIGHT...North wind 5 to 10 knots. Gusts up to 20 knots
early in the evening. Mostly cloudy in the evening then becoming
partly cloudy. Waves 4 to 6 feet subsiding to 1 to 3 feet after
midnight. Waves occasionally to 7 feet. A small craft advisory
may be needed.
.THURSDAY...North wind 5 knots becoming east in the afternoon.
Mostly sunny. Waves 1 to 2 feet.

$$

LSZ144-211015-
Two Harbors to Duluth MN-
1009 PM CDT Tue May 20 2025

...GALE WARNING IN EFFECT THROUGH WEDNESDAY AFTERNOON...

.REST OF TONIGHT...Northeast wind 20 to 25 knots with gales to
around 35 knots. Rain showers likely in the late evening and
early morning, then chance of rain showers toward daybreak. Waves
7 to 10 feet. Waves occasionally to 13 feet.
.WEDNESDAY...Northeast wind 20 to 25 knots. Gusts up to 35 knots
decreasing to 30 knots late in the afternoon. Slight chance of
rain showers in the morning. Waves 6 to 9 feet. Waves
occasionally to 12 feet.
.WEDNESDAY NIGHT...Northeast wind 15 to 20 knots with gusts to
around 25 knots becoming north 5 to 10 knots after midnight.
Mostly cloudy in the evening then becoming partly cloudy. Waves
4 to 6 feet subsiding to 1 to 2 feet. Waves occasionally to
8 feet. A small craft advisory may be needed.
.THURSDAY...Northeast wind 5 to 10 knots. Mostly sunny. Waves
1 to 2 feet.

$$

LSZ145-211015-
Duluth MN to Port Wing WI-
1009 PM CDT Tue May 20 2025

...GALE WARNING IN EFFECT THROUGH WEDNESDAY AFTERNOON...

.REST OF TONIGHT...Northeast wind up to 30 knots. Gusts up to
35 knots. Rain showers likely in the late evening and early
morning, then chance of rain showers toward daybreak. Waves 7 to
10 feet. Waves occasionally to 13 feet.
.WEDNESDAY...Northeast wind 20 to 25 knots. Gusts up to around 35
knots, then decreasing to 30 knots in the afternoon. Slight
chance of rain showers in the morning. Waves 6 to 9 feet. Waves
occasionally to 12 feet.
.WEDNESDAY NIGHT...Northeast wind 15 to 20 knots with gusts to
around 25 knots easing to 5 to 10 knots after midnight. Mostly
cloudy. Waves 4 to 6 feet subsiding to 1 to 3 feet. Waves
occasionally to 8 feet. A small craft advisory may be needed.
.THURSDAY...Northeast wind 5 to 10 knots. Mostly sunny. Waves
1 to 2 feet.

$$

LSZ146-211015-
Port Wing to Sand Island WI-
1009 PM CDT Tue May 20 2025

...GALE WARNING IN EFFECT UNTIL 1 AM CDT WEDNESDAY...

.REST OF TONIGHT...Northeast wind 20 to 25 knots with gusts to
around 30 knots. Chance of rain showers in the late evening and
early morning, then slight chance of rain showers toward
daybreak. Waves 6 to 9 feet. Waves occasionally to 11 feet.
.WEDNESDAY...Northeast wind 20 to 25 knots. Gusts up to around 30
knots. Cloudy. Waves 6 to 9 feet. Waves occasionally to 11 feet.
.WEDNESDAY NIGHT...Northeast wind 10 to 15 knots. Gusts up to
25 knots early in the evening. Mostly cloudy in the evening then
becoming partly cloudy. Waves 4 to 6 feet subsiding to 1 to
3 feet after midnight. Waves occasionally to 8 feet. A small
craft advisory may be needed.
.THURSDAY...Northeast wind 5 to 10 knots easing to 5 knots late
in the afternoon. Mostly sunny. Waves 1 to 2 feet.

$$

LSZ147-211015-
Sand Island to Bayfield WI-
1009 PM CDT Tue May 20 2025

...GALE WARNING IN EFFECT UNTIL 1 AM CDT WEDNESDAY...

.REST OF TONIGHT...Northeast wind 20 to 25 knots with gusts to
around 30 knots. Chance of rain showers in the late evening and
early morning, then slight chance of rain showers toward
daybreak. Waves 5 to 8 feet. Waves occasionally to 10 feet.
.WEDNESDAY...Northeast wind 20 to 25 knots. Gusts up to 30 knots
increasing to 35 knots in the late morning and early afternoon,
then decreasing to 30 knots late in the afternoon. Mostly cloudy.
Waves 5 to 8 feet. Waves occasionally to 10 feet. A gale warning
may be needed.
.WEDNESDAY NIGHT...Northeast wind 10 to 15 knots. Gusts up to
20 knots early in the evening. Mostly cloudy in the evening then
becoming partly cloudy. Waves 3 to 5 feet subsiding to 1 to
3 feet after midnight. Waves occasionally to 7 feet. A small
craft advisory may be needed.
.THURSDAY...North wind 5 to 10 knots becoming east in the
afternoon. Mostly sunny. Waves 1 to 2 feet.

$$

LSZ150-211015-
Outer Apostle Islands Beyond 5 NM from Mainland-
1009 PM CDT Tue May 20 2025

...GALE WARNING IN EFFECT UNTIL 1 AM CDT WEDNESDAY...

.REST OF TONIGHT...Northeast wind 20 to 25 knots. Gusts up to
35 knots decreasing to 30 knots after midnight. Chance of rain
showers in the late evening and early morning, then slight chance
of rain showers toward daybreak. Waves 6 to 9 feet. Waves
occasionally to 12 feet.
.WEDNESDAY...Northeast wind 20 to 25 knots. Gusts up to 35 knots
decreasing to 30 knots late in the afternoon. Mostly cloudy.
Waves 6 to 9 feet. Waves occasionally to 12 feet. A gale warning
may be needed.
.WEDNESDAY NIGHT...Northeast wind 15 to 20 knots with gusts to
around 25 knots easing to 5 to 10 knots with gusts to around
20 knots in the late evening and overnight. Mostly cloudy in the
evening then becoming partly cloudy. Waves 4 to 7 feet subsiding
to 1 to 3 feet. Waves occasionally to 9 feet. A small craft
advisory may be needed.
.THURSDAY...North wind 5 to 10 knots becoming east in the
afternoon. Mostly sunny. Waves 1 to 3 feet.

$$

LSZ121-211015-
Chequamegon Bay-Bayfield to Oak Point WI-
1009 PM CDT Tue May 20 2025

...GALE WARNING IN EFFECT UNTIL 1 AM CDT WEDNESDAY...

.REST OF TONIGHT...Northeast wind 15 to 20 knots. Gusts up to
35 knots decreasing to 30 knots after midnight, then decreasing
to 25 knots toward daybreak. Chance of rain showers. Waves 1 to 3
feet.
.WEDNESDAY...Northeast wind 15 to 20 knots. Gusts up to 25 knots
increasing to 30 knots in the late morning and afternoon. Slight
chance of rain showers in the morning. Waves 1 to 3 feet.
.WEDNESDAY NIGHT...Northeast wind 10 to 15 knots. Gusts up to
25 knots early in the evening. Mostly cloudy in the evening then
becoming partly cloudy. Waves 1 to 3 feet.
.THURSDAY...Northeast wind 5 to 10 knots. Mostly sunny. Waves
1 foot or less.

$$

LSZ148-211015-
Oak Point to Saxon Harbor WI-
1009 PM CDT Tue May 20 2025

...GALE WARNING IN EFFECT UNTIL 1 AM CDT WEDNESDAY...

.REST OF TONIGHT...Northeast wind 15 to 20 knots. Gusts up to
35 knots decreasing to 30 knots after midnight, then decreasing
to 25 knots toward daybreak. Chance of rain showers. Waves 7 to 10
feet. Waves occasionally to 12 feet.
.WEDNESDAY...Northeast wind 20 to 25 knots. Gusts up to 25 knots
increasing to 30 knots in the late morning and afternoon. Slight
chance of rain showers in the morning. Waves 5 to 8 feet. Waves
occasionally to 11 feet. A small craft advisory may be needed.
.WEDNESDAY NIGHT...Northeast wind 15 to 20 knots with gusts to
around 25 knots easing to 5 to 10 knots with gusts to around
20 knots in the late evening and overnight. Mostly cloudy in the
evening then becoming partly cloudy. Waves 4 to 7 feet subsiding
to 1 to 3 feet. Waves occasionally to 9 feet. A small craft
advisory may be needed.
.THURSDAY...Northeast wind 5 to 10 knots. Mostly sunny. Waves
1 to 3 feet.

$$

Graphical marine forecasts are available online at:
weather.gov/greatlakes

Rothstein

Open Waters Forecast

509
FZUS63 KMQT 210207
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
Issued by National Weather Service Gaylord MI
1007 PM EDT Tue May 20 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...

A 29.6 inch low pressure resides over northern IL with 30.6 inch
surface high over the Hudson Bay. The surface low will remain
weaker and continue eastward towards southern MI Wednesday. It
will reside between Lk Erie and Lk Ontario Thursday. A 30.3inch
surface high will start to move south over the northern plains
on Thursday as well, building over western Lk Superior Friday.


LSZ162-211015-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1007 PM EDT Tue May 20 2025 /907 PM CDT Tue May 20 2025/

...GALE WARNING IN EFFECT THROUGH WEDNESDAY AFTERNOON...

.LATE THIS AFTERNOON...Northeast gales to 45 knots. A chance of
rain showers. Waves 11 to 15 feet occasionally to 19 feet
subsiding to 10 to 14 feet occasionally to 18 feet.
.TONIGHT...East gales to 40 knots becoming northeast gales to
35 knots late. A chance of rain showers. Waves subsiding to 5 to
8 feet occasionally to 10 feet, then building to 6 to 9 feet
occasionally to 11 feet.
.WEDNESDAY...Northeast gales to 35 knots diminishing to 20 to
30 knots in the afternoon. A slight chance of rain showers
through early afternoon. Waves building to 7 to 10 feet
occasionally to 13 feet, then subsiding to 4 to 7 feet
occasionally to 9 feet.
.WEDNESDAY NIGHT...Northeast winds 10 to 20 knots backing north
after midnight. Waves subsiding to 1 to 3 feet.
.THURSDAY...North winds 10 to 20 knots becoming east 5 to
15 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.THURSDAY NIGHT...North winds 5 to 15 knots. Waves calm to
2 feet.
.FRIDAY...North winds 5 to 15 knots veering south by mid
afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...East winds 5 to 15 knots backing north after
midnight. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots backing northeast. Waves
calm to 2 feet.
.SUNDAY...Northeast winds 5 to 15 knots backing northwest. Waves
calm to 2 feet.

$$

LSZ263-211015-
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-
1007 PM EDT Tue May 20 2025

...GALE WARNING IN EFFECT UNTIL 10 PM EDT THIS EVENING...

.LATE THIS AFTERNOON...East gales to 40 knots. A slight chance of
rain showers. Waves 9 to 12 feet occasionally to 15 feet
subsiding to 8 to 11 feet occasionally to 14 feet.
.TONIGHT...East gales to 35 knots diminishing to 20 to 30 knots
after midnight. A slight chance of rain showers through midnight.
Waves subsiding to 3 to 6 feet occasionally to 8 feet, then
building to 5 to 8 feet occasionally to 10 feet.
.WEDNESDAY...Northeast winds 20 to 30 knots. Waves building to
6 to 9 feet occasionally to 11 feet, then subsiding to 4 to
7 feet occasionally to 9 feet.
.WEDNESDAY NIGHT...Northeast winds 10 to 20 knots diminishing to
5 to 15 knots after midnight, then backing north late. Waves
subsiding to 2 to 4 feet.
.THURSDAY...North winds 10 to 20 knots. Waves subsiding to 1 to
3 feet.
.THURSDAY NIGHT...North winds 10 to 20 knots. Waves 1 to 3 feet.
.FRIDAY...North winds 5 to 15 knots. Waves subsiding to calm to
2 feet.
.FRIDAY NIGHT...Northwest winds 5 to 15 knots veering north after
midnight. Waves calm to 2 feet.
.SATURDAY...Northeast winds 5 to 15 knots backing north. Waves
calm to 2 feet.
.SUNDAY...North winds 5 to 15 knots backing west. Waves calm to
2 feet.

$$

LSZ264-211015-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1007 PM EDT Tue May 20 2025

.LATE THIS AFTERNOON...East winds 20 to 25 knots. Waves 4 to 7
feet occasionally to 9 feet subsiding to 3 to 5 feet occasionally
to 7 feet.
.TONIGHT...East winds 20 to 30 knots. Waves subsiding to 2 to
4 feet, then building to 5 to 8 feet occasionally to 10 feet.
.WEDNESDAY...Northeast winds 20 to 30 knots diminishing to 15 to
25 knots in the afternoon. Waves subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...Northeast winds 10 to 20 knots backing north
late. Waves subsiding to 1 to 3 feet, then building to 2 to
4 feet.
.THURSDAY...North winds 10 to 20 knots. Waves subsiding to 1 to
3 feet.
.THURSDAY NIGHT...North winds 10 to 20 knots. Waves building to
2 to 4 feet.
.FRIDAY...North winds 5 to 15 knots. Waves subsiding to calm to
2 feet.
.FRIDAY NIGHT...Northwest winds 5 to 15 knots veering north after
midnight. Waves calm to 2 feet.
.SATURDAY...North winds 5 to 15 knots becoming northwest less
than 10 knots. Waves calm to 2 feet.
.SUNDAY...North winds 5 to 15 knots becoming northwest less than
10 knots. Waves calm to 2 feet.

$$

LSZ265-211015-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1007 PM EDT Tue May 20 2025

.LATE THIS AFTERNOON...East winds 20 to 25 knots. Waves 4 to 7
feet occasionally to 9 feet subsiding to 3 to 6 feet occasionally
to 8 feet.
.TONIGHT...East winds 15 to 25 knots increasing to 20 to 30 knots
late. Waves subsiding to 2 to 4 feet, then building to 4 to
7 feet occasionally to 9 feet.
.WEDNESDAY...East winds 20 to 30 knots backing northeast in the
afternoon, then diminishing to 15 to 25 knots late. Waves
subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...Northeast winds 10 to 20 knots becoming north
15 to 25 knots late. Waves subsiding to 1 to 3 feet, then
building to 2 to 4 feet.
.THURSDAY...North winds 15 to 25 knots. Waves 2 to 4 feet.
.THURSDAY NIGHT...North winds 10 to 20 knots. Waves subsiding to
1 to 3 feet.
.FRIDAY...North winds 10 to 20 knots. Waves subsiding to calm to
2 feet.
.FRIDAY NIGHT...Northwest winds 10 to 20 knots diminishing to
5 to 15 knots after midnight. Waves calm to 2 feet.
.SATURDAY...North winds 5 to 15 knots backing northwest. Waves
calm to 2 feet.
.SUNDAY...North winds 5 to 15 knots backing northwest. Waves calm
to 2 feet.

$$

LSZ266-211015-
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-
1007 PM EDT Tue May 20 2025

.LATE THIS AFTERNOON...East winds 20 to 25 knots. Waves 3 to 6
feet occasionally to 8 feet.
.TONIGHT...East winds 15 to 25 knots increasing to 20 to 30 knots
after midnight. Waves subsiding to 2 to 4 feet, then building to
4 to 7 feet occasionally to 9 feet.
.WEDNESDAY...Northeast winds 20 to 30 knots diminishing to 15 to
25 knots in the afternoon. Waves subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...Northeast winds 15 to 25 knots backing north
late. Waves 2 to 4 feet.
.THURSDAY...North winds 15 to 25 knots. A slight chance of rain
showers. Waves building to 3 to 5 feet occasionally to 7 feet.
.THURSDAY NIGHT...North winds 15 to 25 knots. A chance of rain
showers. Waves subsiding to 2 to 4 feet.
.FRIDAY...North winds 15 to 25 knots becoming northwest 10 to
20 knots by mid afternoon. Waves 2 to 4 feet.
.FRIDAY NIGHT...Northwest winds 10 to 20 knots veering north
after midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...Northwest winds 10 to 20 knots diminishing to 5 to
15 knots. Waves calm to 2 feet.
.SUNDAY...Northwest winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ267-211015-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1007 PM EDT Tue May 20 2025

.LATE THIS AFTERNOON...Northeast winds 10 to 20 knots. Waves 1 to
3 feet subsiding to calm to 2 feet.
.TONIGHT...East winds 15 to 25 knots backing northeast late.
Waves building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...Northeast winds 15 to 25 knots. Waves subsiding to
2 to 4 feet.
.WEDNESDAY NIGHT...Northeast winds 15 to 25 knots backing north
late. Waves 2 to 4 feet.
.THURSDAY...North winds 15 to 25 knots. A slight chance of rain
showers. Waves 2 to 4 feet.
.THURSDAY NIGHT...North winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. A chance of rain showers. Waves 2 to
4 feet.
.FRIDAY...North winds 10 to 20 knots backing northwest by mid
afternoon. A chance of rain showers. Waves 2 to 4 feet.
.FRIDAY NIGHT...Northwest winds 10 to 20 knots veering north
after midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...Northwest winds 10 to 20 knots. Waves calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots diminishing to 5 to
15 knots. Waves calm to 2 feet.

$$
LSZ261-211015-
MAFOR 2103/
Superior West...GALE WARNING IN EFFECT...11240 11250 13150 12140
11110. Waves omitted due to the lake being mostly ice covered.

Superior North Central 12240 13140 12130 11120. Waves omitted due
to the lake being mostly ice covered.

Superior South Central 11230 13240 11140 11130 11120 11110. Waves
omitted due to the lake being mostly ice covered.

Superior East 11240 13140 13130 11120. Waves omitted due to the
lake being mostly ice covered.

$$

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

Beach Hazards

This product is only issued between May 26th and October 1st.

Other Information

Great Lakes Water Levels and Forecasts - Provided by USACE

GLERL - NOAA Great Lakes Forecast System

NWS Marine Homepage

Cold Water Safety

Park Point Beach Information

Paddle Safe Twin Ports