Small Craft Advisory 207, NWS Juneau, AK

258 
FZAK51 PAJK 061204
CWFAJK

Coastal Waters Forecast for Southeast Alaska
National Weather Service Juneau AK
404 AM AKDT Tue Apr 6 2021

Southeast Alaska Inside Waters from Dixon Entrance to Skagway

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent the average of the highest
one-third of the combined windwave and swell height.

PKZ098-070330-
404 AM AKDT Tue Apr 6 2021
.SYNOPSIS FOR SOUTHEAST ALASKA INNER CHANNELS COASTAL WATERS...
An area of low pressure over the NE Gulf will weaken as it tracks
SE through Wednesday. Outlook. A gale force low and front will 
move into the AK Gulf Thursday. 

$$

PKZ011-070330-
Glacier Bay-
404 AM AKDT Tue Apr 6 2021

.TODAY...S wind 10 kt. Seas 2 ft or less. Snow showers and rain
showers in the morning. 
.TONIGHT...S wind 15 kt becoming N late. Seas 3 ft. 
.WED...N wind 15 kt. Seas 3 ft. 
.WED NIGHT...NE wind 15 kt. Seas 3 ft. 
.THU...SE wind 20 kt becoming N. Seas 4 ft. 
.FRI...NW wind 20 kt. Seas 4 ft. 
.SAT...N wind 20 kt. Seas 4 ft. 

$$

PKZ012-070330-
Northern Lynn Canal-
404 AM AKDT Tue Apr 6 2021

...SMALL CRAFT ADVISORY LATE TONIGHT...

.TODAY...SW wind 20 kt diminishing in the afternoon. Seas 4 ft. 
Snow showers early in the morning. Rain showers. 
.TONIGHT...S wind 15 kt becoming N 30 kt late. Seas 3 ft building
to 6 ft late. 
.WED...N wind 30 kt. Seas 6 ft. 
.WED NIGHT...N wind 20 kt becoming S 15 kt late. Seas 4 ft. 
.THU...SE wind 15 kt becoming N. Seas 4 ft. 
.FRI...N wind 25 kt. Seas 5 ft. 
.SAT...N wind 25 kt becoming S 15 kt. Seas 4 ft. 

$$

PKZ013-070330-
Southern Lynn Canal-
404 AM AKDT Tue Apr 6 2021

...SMALL CRAFT ADVISORY LATE TONIGHT...

.TODAY...S wind 20 kt diminishing in the afternoon. Seas 4 ft. 
Snow showers early in the morning. Rain showers. 
.TONIGHT...S wind 15 kt becoming N 30 kt late. Gusts to 45 kt
late. Seas 3 ft building to 6 ft late. 
.WED...N wind 30 kt. Seas 6 ft. 
.WED NIGHT...N wind 15 kt becoming S late. Seas 3 ft. 
.THU...SE wind 25 kt. Seas 5 ft. 
.FRI...N wind 20 kt. Seas 4 ft. 
.SAT...N wind 20 kt becoming SE 10 kt. Seas 4 ft then 2 ft
or less. 

$$

PKZ021-070330-
Icy Strait-
404 AM AKDT Tue Apr 6 2021

.TODAY...SE wind 10 kt. Seas 2 ft or less. Rain showers and snow 
showers early in the morning. 
.TONIGHT...SE wind 10 kt becoming NW 15 kt late. Seas building to
3 ft late. 
.WED...NW wind 15 kt. Seas 3 ft in the morning then 2 ft or
less. 
.WED NIGHT...NE wind 15 kt. Seas 3 ft. 
.THU...E wind 25 kt. Seas 5 ft. 
.FRI...E wind 15 kt. Seas 3 ft. 
.SAT...E wind 15 kt. Seas 3 ft. 

$$

PKZ022-070330-
Cross Sound-
404 AM AKDT Tue Apr 6 2021

.TODAY...SW wind 15 kt. Seas 7 ft. Rain showers early in the 
morning. 
.TONIGHT...S wind 10 kt becoming E late. Seas 7 ft. 
.WED...NE wind 15 kt. Seas 6 ft. 
.WED NIGHT...NE wind 15 kt. Seas 5 ft. Rain and snow. 
.THU...E wind 25 kt. Seas 11 ft. 
.FRI...E wind 20 kt. Seas 12 ft. 
.SAT...E wind 15 kt. Seas 8 ft. 

$$

PKZ031-070330-
Stephens Passage-
404 AM AKDT Tue Apr 6 2021

.TODAY...S wind 15 kt. Seas 3 ft. Snow showers early in the
morning. Rain showers. 
.TONIGHT...SE wind 15 kt. Seas 3 ft. Rain showers and snow
showers in the evening. 
.WED...N wind 20 kt. Seas 4 ft. 
.WED NIGHT...N wind 15 kt. Seas 3 ft. 
.THU...SE gale to 35 kt. Seas 7 ft. 
.FRI...SE wind 20 kt becoming N. Seas 4 ft. 
.SAT...S wind 10 kt. Seas 3 ft. 

$$

PKZ032-070330-
Northern Chatham Strait-
404 AM AKDT Tue Apr 6 2021

...SMALL CRAFT ADVISORY LATE TONIGHT...

.TODAY...S wind 15 kt. Seas 3 ft. Rain showers. 
.TONIGHT...S wind 10 kt becoming N 25 kt late. Seas building to 5
ft late. 
.WED...NW wind 25 kt diminishing in the afternoon. Seas 5 ft. 
.WED NIGHT...NW wind 15 kt. Seas 3 ft. 
.THU...SE gale to 35 kt. Seas 7 ft. 
.FRI...SE wind 20 kt becoming N. Seas 4 ft. 
.SAT...S wind 15 kt. Seas 3 ft. 

$$

PKZ033-070330-
Southern Chatham Strait-
404 AM AKDT Tue Apr 6 2021

.TODAY...S wind 15 kt. Seas 3 ft, except 6 ft near ocean
entrances. Rain showers. 
.TONIGHT...S wind 15 kt. Seas building to 3 ft late. Near ocean
entrances, seas 7 ft. 
.WED...N wind 20 kt. Seas 4 ft, except 7 ft near ocean
entrances. 
.WED NIGHT...NW wind 15 kt. Seas 3 ft, except 7 ft near
ocean entrances. 
.THU...S wind 30 kt. Seas 7 ft. 
.FRI...S wind 20 kt becoming N 10 kt. Seas 4 ft then 2 ft or
less. 
.SAT...S wind 10 kt. Seas 2 ft or less. 

$$

PKZ034-070330-
Frederick Sound-
404 AM AKDT Tue Apr 6 2021

.TODAY...S wind 15 kt. Seas 3 ft. Rain showers. 
.TONIGHT...S wind 15 kt. Seas 3 ft in the evening then 2 ft or
less. 
.WED...N wind 15 kt. Seas 3 ft. 
.WED NIGHT...SE wind 15 kt. Seas 3 ft. 
.THU...SE gale to 35 kt. Seas 7 ft. 
.FRI...SE wind 20 kt becoming NW 10 kt. Seas 4 ft then 2 ft or
less. 
.SAT...SE wind 10 kt. Seas 2 ft or less. 

$$

PKZ035-070330-
Sumner Strait-
404 AM AKDT Tue Apr 6 2021

.TODAY...S wind 15 kt. Seas 3 ft. Rain showers. 
.TONIGHT...S wind 15 kt. Seas 2 ft or less, except 5 ft near
ocean entrances. Rain showers in the evening. 
.WED...W wind 10 kt. Seas 3 ft in the morning then 2 ft or
less. Near ocean entrances, seas 5 ft. 
.WED NIGHT...S wind 15 kt. Seas 3 ft, except 6 ft near
ocean entrances. 
.THU...S gale to 35 kt. Seas 7 ft. 
.FRI...S wind 20 kt becoming E 10 kt. Seas 4 ft then 2 ft or
less. 
.SAT...SE wind 10 kt. Seas 2 ft or less. 

$$

PKZ036-070330-
Clarence Strait-
404 AM AKDT Tue Apr 6 2021

.TODAY...S wind 15 kt. Seas building to 3 ft in the afternoon.
Rain showers. 
.TONIGHT...S wind 15 kt becoming NW 10 kt late. Seas 3 ft in the 
evening then 2 ft or less. Rain showers in the evening. 
.WED...NW wind 15 kt. Seas 3 ft. 
.WED NIGHT...NW wind 15 kt. Seas 3 ft. 
.THU...S wind 30 kt. Seas 7 ft. 
.FRI...SE wind 15 kt. Seas 6 ft subsiding to 3 ft. 
.SAT...S wind 10 kt. Seas building to 4 ft. 

$$

130 
FZAK51 PAJK 062337
CWFAJK

Coastal Waters Forecast for Southeast Alaska
National Weather Service Juneau AK
337 PM AKDT Tue Apr 6 2021

Southeast Alaska Inside Waters from Dixon Entrance to Skagway

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent the average of the highest
one-third of the combined windwave and swell height.

PKZ098-071830-
337 PM AKDT Tue Apr 6 2021
.SYNOPSIS FOR SOUTHEAST ALASKA INNER CHANNELS COASTAL WATERS...
An area of low pressure over the NE Gulf will weaken as it
tracks SE through Wednesday. A gale force low and front will
move into the AK Gulf Thursday then weaken through Friday.  

$$

PKZ011-071830-
Glacier Bay-
337 PM AKDT Tue Apr 6 2021

.TONIGHT...S wind 15 kt becoming NW 20 kt late. Seas building to 
4 ft. 
.WED...N wind 20 kt. Seas 4 ft.
.WED NIGHT...NE wind 10 kt becoming SE 15 kt late. Seas building
to 3 ft late. 
.THU...SE wind 25 kt. Gusts to 40 kt. Seas 5 ft. Rain and
snow. 
.THU NIGHT...SE wind 20 kt. Seas 4 ft. Rain with snow. 
.FRI...NW wind 20 kt. Seas 4 ft. 
.SAT...N wind 20 kt. Seas 4 ft. 
.SUN...SE wind 10 kt. Seas 2 ft or less. 

$$

PKZ012-071830-
Northern Lynn Canal-
337 PM AKDT Tue Apr 6 2021

...GALE WARNING LATE TONIGHT THROUGH WEDNESDAY...

.TONIGHT...S wind 20 kt becoming N 35 kt late. Seas 4 ft building
to 7 ft late. 
.WED...N wind 35 kt. Seas 7 ft. 
.WED NIGHT...N wind 20 kt. Gusts to 35 kt late. Seas 4 ft. 
.THU...SE wind 20 kt. Seas 4 ft. Rain with snow. 
.THU NIGHT...S wind 20 kt. Seas 4 ft. Rain with snow. 
.FRI...N wind 25 kt. Seas 5 ft. 
.SAT...N wind 25 kt becoming S 15 kt. Seas 4 ft. 
.SUN...S wind 10 kt. Seas 2 ft or less. 

$$

PKZ013-071830-
Southern Lynn Canal-
337 PM AKDT Tue Apr 6 2021

...GALE WARNING LATE TONIGHT THROUGH WEDNESDAY...

.TONIGHT...S wind 20 kt becoming N 35 kt late. Seas 4 ft building
to 7 ft late. 
.WED...N wind 35 kt. Seas 7 ft. 
.WED NIGHT...N wind 15 kt becoming SE late. Seas 3 ft. 
.THU...SE wind 30 kt. Seas 6 ft. Rain with snow. 
.THU NIGHT...SE wind 20 kt. Seas 4 ft. Rain.
.FRI...N wind 20 kt. Seas 4 ft. 
.SAT...N wind 20 kt becoming SE 10 kt. Seas 4 ft then 2 ft
or less. 
.SUN...SE wind 10 kt. Seas 2 ft or less. 

$$

PKZ021-071830-
Icy Strait-
337 PM AKDT Tue Apr 6 2021

.TONIGHT...SE wind 10 kt becoming NW 20 kt late. Seas building to
4 ft late. 
.WED...NW wind 20 kt diminishing. Seas 4 ft in the morning then 2
ft or less.
.WED NIGHT...NW wind 10 kt becoming SE 15 kt late. Seas building
to 3 ft late. 
.THU...E wind 30 kt. Seas 6 ft. Rain with snow. 
.THU NIGHT...E wind 20 kt. Seas 4 ft. Rain.
.FRI...E wind 15 kt. Seas 3 ft. 
.SAT...E wind 15 kt. Seas 3 ft. 
.SUN...SE wind 10 kt. Seas 2 ft or less. 

$$

PKZ022-071830-
Cross Sound-
337 PM AKDT Tue Apr 6 2021

.TONIGHT...W wind 10 kt becoming E 20 kt late. Seas 7 ft. 
.WED...NE wind 20 kt. Seas 7 ft. 
.WED NIGHT...Light winds becoming E 20 kt late. Seas 5 ft.
Rain and snow late. 
.THU...E gale to 35 kt. Seas 11 ft. Rain and snow. 
.THU NIGHT...E wind 25 kt. Seas 13 ft. Rain.
.FRI...E wind 25 kt diminishing to 15 kt. Seas 12 ft. 
.SAT...E wind 15 kt. Seas 8 ft. 
.SUN...E wind 15 kt. Seas 9 ft. 

$$

PKZ031-071830-
Stephens Passage-
337 PM AKDT Tue Apr 6 2021

...SMALL CRAFT ADVISORY WEDNESDAY...

.TONIGHT...S wind 15 kt becoming NW 20 kt late. Seas 4 ft. Rain
showers in the evening. 
.WED...N wind 25 kt. Seas 5 ft. 
.WED NIGHT...N wind 15 kt becoming SE late. Seas 3 ft. 
.THU...SE gale to 35 kt. Seas 7 ft. Rain with snow. 
.THU NIGHT...SE wind 30 kt. Gusts to 45 kt. Seas 6 ft. Rain.
.FRI...SE wind 25 kt becoming N 15 kt. Seas 4 ft. 
.SAT...S wind 10 kt. Seas 3 ft. 
.SUN...S wind 10 kt. Seas building to 3 ft. 

$$

PKZ032-071830-
Northern Chatham Strait-
337 PM AKDT Tue Apr 6 2021

...SMALL CRAFT ADVISORY LATE TONIGHT THROUGH WEDNESDAY...

.TONIGHT...S wind 15 kt becoming N 25 kt late. Seas 3 ft then 5 
ft late. Rain showers early in the evening. 
.WED...NW wind 25 kt. Gusts to 40 kt. Seas 5 ft. 
.WED NIGHT...NW wind 15 kt becoming SE late. Seas 3 ft. 
.THU...SE gale to 35 kt. Seas 7 ft. Rain and snow. 
.THU NIGHT...SE wind 30 kt. Gusts to 45 kt. Seas 6 ft. Rain.
.FRI...SE wind 20 kt becoming N. Seas 4 ft. 
.SAT...S wind 15 kt. Seas 3 ft. 
.SUN...S wind 10 kt. Seas 2 ft or less. 

$$

PKZ033-071830-
Southern Chatham Strait-
337 PM AKDT Tue Apr 6 2021

...SMALL CRAFT ADVISORY WEDNESDAY...

.TONIGHT...S wind 15 kt becoming NW late. Seas 3 ft. Near ocean 
entrances, seas 7 ft. 
.WED...N wind 25 kt. Seas 5 ft, except 7 ft near ocean
entrances. 
.WED NIGHT...NW wind 15 kt becoming S late. Seas 3 ft,
except 7 ft near ocean entrances. 
.THU...SE gale to 40 kt. Seas 8 ft, except 13 ft near ocean 
entrances. Rain and snow. 
.THU NIGHT...S wind 30 kt. Seas 6 ft, except 15 ft near
ocean entrances. Rain.
.FRI...S wind 20 kt becoming N 10 kt. Seas 4 ft then 2 ft or
less. 
.SAT...S wind 10 kt. Seas 2 ft or less. 
.SUN...S wind 15 kt. Seas building to 3 ft. 

$$

PKZ034-071830-
Frederick Sound-
337 PM AKDT Tue Apr 6 2021

.TONIGHT...S wind 15 kt becoming NW late. Seas 3 ft. Rain showers
early in the evening. 
.WED...N wind 20 kt. Seas 4 ft. 
.WED NIGHT...NW wind 15 kt becoming SE late. Seas 3 ft. 
.THU...SE gale to 35 kt. Seas 7 ft. Rain and snow. 
.THU NIGHT...SE wind 30 kt. Gusts to 45 kt. Seas 6 ft. Rain.
.FRI...SE wind 25 kt becoming NW 10 kt. Seas 5 ft then 2 ft or
less. 
.SAT...SE wind 10 kt. Seas 2 ft or less. 
.SUN...S wind 15 kt. Seas 3 ft. 

$$

PKZ035-071830-
Sumner Strait-
337 PM AKDT Tue Apr 6 2021

.TONIGHT...SW wind 10 kt. Seas 2 ft or less. Near ocean 
entrances, seas 6 ft. Rain showers early in the evening. 
.WED...W wind 15 kt. Seas 3 ft, except 6 ft near ocean
entrances. 
.WED NIGHT...NW wind 15 kt becoming E late. Seas 3 ft,
except 6 ft near ocean entrances. 
.THU...E gale to 35 kt. Seas 7 ft, except 10 ft near ocean 
entrances. Rain with snow. 
.THU NIGHT...S gale to 35 kt. Gusts to 45 kt. Seas 7 ft, except 
12 ft near ocean entrances. Rain.
.FRI...S wind 20 kt becoming E 10 kt. Seas 4 ft then 2 ft or
less. 
.SAT...SE wind 10 kt. Seas 2 ft or less. 
.SUN...S wind 15 kt. Seas building to 3 ft. 

$$

PKZ036-071830-
Clarence Strait-
337 PM AKDT Tue Apr 6 2021

.TONIGHT...S wind 15 kt becoming NW late. Seas 3 ft. Rain showers
in the evening. 
.WED...NW wind 15 kt. Seas 3 ft. 
.WED NIGHT...NW wind 15 kt. Seas 3 ft. 
.THU...SE gale to 40 kt. Seas 10 ft. Rain.
.THU NIGHT...S gale to 35 kt. Gusts to 45 kt. Seas 9 ft, except 
12 ft near ocean entrances. Rain.
.FRI...SE wind 15 kt. Seas 4 ft. 
.SAT...S wind 10 kt. Seas building to 4 ft. 
.SUN...S wind 15 kt. Seas 5 ft. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
246 PM AKDT Mon Apr 5 2021

.SHORT TERM.../Through Wednesday/ Residual rain showers persisted
across much of the Panhandle Monday from Juneau and Gustavus
southward in southwesterly flow spawned by a Panhandle ridge. An
impulse in the 500 flow pattern has enhanced showers along the
coast and Coast Mountains, but as it passes southeast, intensity
should ease into Monday night. What does arrive this evening is a
fresh lobe of colder air aloft (models coalescing around -8 C at
850 mb). Thus, we fully expect rain showers to once again mix
with or transition to snow showers late tonight. Instability will
increase overnight, but 850-500mb lapse rates do not impress, so
we are not looking at heavier showers. The best chance of
accumulations will be early Tuesday morning as a weak short-wave
crosses Glacier Bay into the Lynn Canal area. Should it manage to
drop south and form a convergence zone of sorts, then we could
have a couple inches of accumulation in Juneau. But confidence is
low. Upper Lynn Canal should be deprived of the moisture found
further south, hence no snow issues are expected here except maybe
an inch or two along the highways. South and coast-ward from
Juneau, temperatures should remain more marginal for
accumulations. Regarding winds, a weakening ridge over the
Panhandle should lessen Skagway and Lynn Canal breeziness through
this evening and drop the Inner Channels to a mild 15 kt.

A stronger shortwave digs southeast across the central gulf on
Tuesday on its way to enhance showers across the southern
Panhandle Tuesday afternoon and evening. Thicknesses will be
marginal for snow, especially given long-trajectory cold air
across the open water, but we have a better chance for snow mixing
into the southern Panhandle Tuesday night than Monday night for
this reason. Meanwhile, a semi-permanent surface low in the
northern gulf (often a fixture in colder, but near zonal northwest
flow aloft over the gulf), will slowly track east and south to lie
offshore of Cross Sound on Tuesday. While this will help focus
showers on the southern and central Panhandle, it should also
lower wind speeds through the Inner Channels even more so from
Tuesday leading into Tuesday night. Lighter winds tend to be more
favorable for snowmelt cooling processes to reach the surface.

Tuesday night should also offer a transition. As the low pulls
into the central Panhandle, northerly winds develop in Lynn Canal
and expand southward into the central Inner Channels through the
night. Gradients and some weak cold air advection imply small
craft northerlies Wednesday morning with lighter north winds of
around 15 kt for the central channels. Far to the south, we expect
the northerly transition sometime mid Wednesday morning. With
northerly surface flow along with more northwest flow aloft from
the Wrangell St. Elias Range and the Alaskan Interior, showers
will retreat southward through Wednesday such that skies become
sunny by the afternoon for much of the north and central
Panhandle. But the break is all too small, as a stronger system
readies to impact the gulf Wednesday night. For more on that, read
below.

.LONG TERM.../Wednesday through Sunday/ As of 10pm Sunday. Behind
the departing trough ridging will begin to rebuild ahead of a
system moving in from the western gulf on Thursday. This system
has the potential to be a high impact event, but pinning down
exact details continues to remain a challenge. Notably enough,
both operational and ensemble suites have continued to differ from
run to run on the track of the system. There has been a general
trend towards moving the system northward, with there being some
indications that the center of the low could pass near the Icy
Strait Corridor. This has only increased uncertainty as late
season cold air wrapping around the N flank of the low could
result in substantial accumulating snow. Consequently, minor
shifts in the track of the low could mean the difference between
much of the panhandle receiving a late season wintry blast, or the
area receiving additional rainfall. The system also has the
potential to bring breezy conditions across the panhandle and the
channels, and all of these elements will need to be closely
monitored as more data becomes available.

The system will likely remain around the area for some time. There
is a possibility of some clearing for Saturday should the system
depart through Friday night as the Euro depicts. On the other
hand, the GFS ensemble shows a slower moving trough aloft
resulting in the low all but stalling over the Gulf for a time.
Should this scenario play out, it is entirely possible that the
system may not depart until Sunday, ahead of another approaching
system which models have begun to depict.

Due to model inconsistencies, there is lower forecast confidence
overall, with the rain/snow line and the exact track of the
Thursday low remaining the primary areas of concern.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind until 10 PM AKDT this evening for AKZ018.
MARINE...Small Craft Advisory for PKZ012-022-041>043-051-052.

&&

JWA/GFS

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