Small Craft Advisory 178, NWS Juneau, AK

799 
FZAK51 PAJK 222342
CWFAJK

Coastal Waters Forecast for Southeast Alaska
National Weather Service Juneau AK
342 PM AKDT Mon Mar 22 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.

PKZ098-231615-
342 PM AKDT Mon Mar 22 2021
.SYNOPSIS FOR SOUTHEAST ALASKA INNER CHANNELS COASTAL WATERS...
A front moves east across the gulf Monday night into Tuesday. 
High pressure moves in on Wednesday as ridging rebuilds across the
gulf. 

$$

PKZ011-231615-
Glacier Bay-
342 PM AKDT Mon Mar 22 2021

.TONIGHT...Light winds becoming NE 15 kt. Seas building to 3 ft
late. Snow late. 
.TUE...N wind 10 kt. Seas 3 ft in the morning then 2 ft or
less. Rain and snow. 
.TUE NIGHT...NW wind 15 kt. Seas 3 ft. 
.WED...S wind 10 kt. Seas 2 ft or less. 
.WED NIGHT...SE wind 10 kt. Seas 2 ft or less. 
.THU...S wind 15 kt. Seas building to 3 ft. 
.FRI...SE wind 15 kt. Seas building to 3 ft. 
.SAT...SE wind 15 kt. Seas 3 ft. 

$$

PKZ012-231615-
Northern Lynn Canal-
342 PM AKDT Mon Mar 22 2021

.TONIGHT...N wind 20 kt. Seas 4 ft. Snow late. 
.TUE...N wind 20 kt. Seas 4 ft. Snow and rain. 
.TUE NIGHT...N wind 20 kt. Gusts to 35 kt late. Seas 4 ft.
Rain showers in the evening. 
.WED...NW wind 15 kt. Seas 3 ft. 
.WED NIGHT...N wind 15 kt. Seas 3 ft. 
.THU...S wind 15 kt becoming SE 25 kt. Seas 5 ft. 
.FRI...S wind 20 kt. Seas 4 ft. 
.SAT...S wind 15 kt. Seas 4 ft. 

$$

PKZ013-231615-
Southern Lynn Canal-
342 PM AKDT Mon Mar 22 2021

.TONIGHT...N wind 20 kt. Seas 4 ft. Rain and snow showers. 
.TUE...N wind 15 kt. Seas 3 ft. Snow in the morning. Rain.
.TUE NIGHT...N wind 20 kt. Seas 4 ft. 
.WED...NW wind 10 kt. Seas 2 ft or less. 
.WED NIGHT...N wind 15 kt. Seas 3 ft. 
.THU...S wind 20 kt. Seas 4 ft. 
.FRI...SE wind 15 kt. Seas 3 ft. 
.SAT...SE wind 15 kt. Seas 3 ft. 

$$

PKZ021-231615-
Icy Strait-
342 PM AKDT Mon Mar 22 2021

.TONIGHT...E wind 15 kt. Seas 3 ft. Rain and snow showers. 
.TUE...E wind 15 kt. Seas 3 ft. Snow in the morning. Rain.
.TUE NIGHT...E wind 10 kt becoming W late. Seas 2 ft or less.
.WED...W wind 15 kt. Seas 3 ft. 
.WED NIGHT...W wind 10 kt. Seas 2 ft or less. 
.THU...S wind 15 kt. Seas 3 ft. 
.FRI...SE wind 20 kt. Seas 4 ft. 
.SAT...SE wind 15 kt. Seas 3 ft. 

$$

PKZ022-231615-
Cross Sound-
342 PM AKDT Mon Mar 22 2021

.TONIGHT...E wind 15 kt. Seas 7 ft. Rain and snow.
.TUE...E wind 20 kt. Seas 7 ft. Rain and snow. 
.TUE NIGHT...NE wind 15 kt. Seas 8 ft. Rain showers in the
evening. 
.WED...W wind 20 kt. Seas 10 ft. 
.WED NIGHT...W wind 10 kt. Seas 8 ft. SW swell. 
.THU...W wind 20 kt. Seas 7 ft. 
.FRI...SW wind 20 kt. Seas 7 ft. 
.SAT...W wind 15 kt becoming N. Seas 7 ft. 

$$

PKZ031-231615-
Stephens Passage-
342 PM AKDT Mon Mar 22 2021

...SMALL CRAFT ADVISORY TUESDAY...

.TONIGHT...Variable wind 10 kt becoming SE 20 kt. Seas building 
to 4 ft. Snow showers in the evening. Rain and snow late. 
.TUE...SE wind 25 kt diminishing to 15 kt in the afternoon.
Gusts to 40 kt in the morning. Seas 5 ft subsiding to 3 ft. Snow 
in the morning. Rain.
.TUE NIGHT...SE wind 15 kt becoming N late. Seas 3 ft. 
.WED...NW wind 10 kt. Seas 2 ft or less. 
.WED NIGHT...NW wind 10 kt. Seas 2 ft or less. 
.THU...S wind 15 kt. Seas building to 3 ft. 
.FRI...SE wind 15 kt. Seas 3 ft. 
.SAT...S wind 20 kt. Seas 4 ft. 

$$

PKZ032-231615-
Northern Chatham Strait-
342 PM AKDT Mon Mar 22 2021

.TONIGHT...SE wind 15 kt. Gusts to 35 kt late. Seas 3 ft. Snow 
showers in the evening. Rain and snow late. 
.TUE...SE wind 20 kt. Gusts to 35 kt in the morning. Seas
4 ft. Rain.
.TUE NIGHT...SE wind 10 kt becoming N late. Seas 2 ft or
less. 
.WED...NW wind 10 kt. Seas 2 ft or less. 
.WED NIGHT...N wind 10 kt. Seas 2 ft or less. 
.THU...S wind 15 kt. Seas building to 3 ft. 
.FRI...S wind 15 kt. Seas 3 ft. 
.SAT...SW wind 10 kt. Seas 3 ft. 

$$

PKZ033-231615-
Southern Chatham Strait-
342 PM AKDT Mon Mar 22 2021

.TONIGHT...Variable wind 10 kt becoming SE 20 kt late. Gusts to 
35 kt late. Seas building to 4 ft late. Near ocean entrances, seas
8 ft. Rain.
.TUE...S wind 20 kt. Gusts to 35 kt in the morning. Seas
4 ft, except 9 ft near ocean entrances. Rain.
.TUE NIGHT...NW wind 10 kt. Seas 2 ft or less, except 9 ft
near ocean entrances. Rain showers in the evening. 
.WED...NW wind 10 kt. Seas 2 ft or less, except 12 ft near
ocean entrances. 
.WED NIGHT...N wind 10 kt. Seas 2 ft or less, except 10 ft
near ocean entrances. 
.THU...S wind 10 kt. Seas 2 ft or less. 
.FRI...S wind 15 kt. Seas building to 3 ft. 
.SAT...S wind 15 kt. Seas 3 ft. 

$$

PKZ034-231615-
Frederick Sound-
342 PM AKDT Mon Mar 22 2021

.TONIGHT...SE wind 10 kt becoming 20 kt late. Gusts to 35 kt 
late. Seas building to 4 ft late. Rain.
.TUE...SE wind 20 kt. Gusts to 35 kt in the morning. Seas
4 ft. Rain.
.TUE NIGHT...SE wind 10 kt becoming W late. Seas 2 ft or
less. Rain showers in the evening. 
.WED...N wind 10 kt. Seas 2 ft or less. 
.WED NIGHT...N wind 10 kt. Seas 2 ft or less. 
.THU...S wind 10 kt. Seas 2 ft or less. 
.FRI...SE wind 15 kt. Seas building to 3 ft. 
.SAT...S wind 20 kt. Seas 4 ft. 

$$

PKZ035-231615-
Sumner Strait-
342 PM AKDT Mon Mar 22 2021

...SMALL CRAFT ADVISORY TUESDAY...

.TONIGHT...Variable wind 10 kt becoming SE 15 kt late. Gusts to 
35 kt late. Seas 2 ft or less in the evening, then 4 ft late. 
Near ocean entrances, seas 6 ft. Rain late. 
.TUE...S wind 25 kt. Seas 5 ft, except 7 ft near ocean entrances.
Rain.
.TUE NIGHT...E wind 15 kt becoming NW late. Seas 3 ft in the
evening then 2 ft or less. Near ocean entrances, seas 7 ft. Rain
showers in the evening. 
.WED...NW wind 15 kt. Seas 3 ft, except 9 ft near ocean
entrances. 
.WED NIGHT...NW wind 15 kt. Seas 3 ft, except 8 ft near
ocean entrances. 
.THU...NW wind 10 kt becoming E. Seas 2 ft or less. 
.FRI...SE wind 10 kt. Seas building to 3 ft. 
.SAT...S wind 15 kt. Seas 3 ft. 

$$

PKZ036-231615-
Clarence Strait-
342 PM AKDT Mon Mar 22 2021

...SMALL CRAFT ADVISORY TUESDAY...

.TONIGHT...SE wind 10 kt becoming 20 kt. Seas building to 4 ft. 
Near ocean entrances, seas 5 ft. Rain late. 
.TUE...SE wind 25 kt. Seas 7 ft, except 10 ft near ocean
entrances. Rain.
.TUE NIGHT...SE wind 15 kt. Seas 5 ft, except 8 ft near ocean
entrances. Rain showers in the evening. 
.WED...NW wind 15 kt. Seas 3 ft, except 8 ft near ocean
entrances. 
.WED NIGHT...NW wind 15 kt. Seas 3 ft, except 8 ft near
ocean entrances. 
.THU...NW wind 10 kt. Seas 2 ft or less. 
.FRI...SE wind 10 kt. Seas building to 3 ft. 
.SAT...S wind 20 kt. Seas 5 ft. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
609 AM AKDT Mon Mar 22 2021

.SHORT TERM.../Through Tuesday night/...Now 2 days into Spring and
a large part of Southeast Alaska continues to get steady snowfall.
The snow total at the weather office for yesterday was over three
inches and more is on the way. The primary reason for this
continues to be the fact that the jet stream remains well to our
south, leaving us on the cold side. The daily climate messages for
3 of our 4 climate stations confirm this; below normal
temperatures. Colder low level air sweeping across the Gulf will
keep temperatures at or below normal for one more day. Thus where
showers do occur, look for rain changing back to snow as we head
into Monday night. However, late Monday night, the next weather
front will approach the panhandle from the southwest. While there
will be more snow associated with this system, there will also be
a warmer low level airmass that will move in from the west as
well. That's the good news. The less than good news is that this
warmer airmass will only clip the southern part of the Panhandle.
This will also be where the highest QPF values will be. So, while
the northern Panhandle is receiving another 1 to 3 inches of snow
on Tuesday, the southern half will receive less than an inch of
snow, but as much as 2 inches of rain.

The Tuesday front also represents the farthest north excursion of
the jet stream, when all of the Panhandle will be briefly either
under the core of the jet or on the warmer south side. A sharp,
positively tilted upper trough will displace the jet to the south
once again by Tuesday afternoon.

.LONG TERM.../Wednesday through Monday as of 10 PM Sunday/...The
models are in pretty good agreement for the majority of the long
term forecast period. They tend to diverge a bit from Sunday,
onward. A ridge over the Gulf will bring westerly onshore flow.
This will bring convective showery activity to the region due to
topographic uplift. That trend will dominate over southeast Alaska
until around Thursday afternoon into Friday when the ridge axis
over the Gulf tilts eastward and a weak storm system looks to
approach the northern Panhandle from the west, bringing increased
chances of precipitation and bringing some enhanced northerly
gradient winds up to small craft over the Lynn Canal area for the
Thursday afternoon into Friday timeframe. There is a chance that a
small convergence zone may setup over the Juneau area and the Icy
Strait corridor to bring some enhanced precipitation for several
hours to the area. A subsequent frontal system looks to move into
the area after that, but model agreement is not as great on the
location, speed, and strength of that system. They do look to
agree that the system will have a long southwesterly moisture
fetch from the central Pacific giving ample moisture supply and an
increased likelihood of appreciable precipitation. Model Integrated
Water Vapor Transport(IVT) values for that system look to approach
600 kg/(ms) as it approaches the Panhandle. Generally, the good
news is that temperatures look to be starting to moderate a bit on
average across southeast Alaska as Spring has officially arrived.
An EC/GFS/NAM/Canadian blend was used to get good average
forecast output for approximately the first 2/3 of the long term
as they were in relatively good agreement. For about the last bit
of the long term, the forecast was gently phased toward WPC due to
decreased forecast confidence.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ022-041>043-051-052.

&&

Fritsch/PRB/JLC

Visit us at http://www.weather.gov/Juneau