Small Craft Advisory 240, NWS Juneau, AK

618 
FZAK51 PAJK 242354
CWFAJK

Coastal Waters Forecast for Southeast Alaska
National Weather Service Juneau AK
354 PM AKDT Sat Apr 24 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.

PKZ098-251645-
354 PM AKDT Sat Apr 24 2021
.SYNOPSIS FOR SOUTHEAST ALASKA INNER CHANNELS COASTAL WATERS...
High pressure moves over the gulf Saturday afternoon and 
gradually slides southeast and weakens through the weekend into 
Monday. 

$$

PKZ011-251645-
Glacier Bay-
354 PM AKDT Sat Apr 24 2021

.TONIGHT...NW wind 15 kt in the evening, then NW 10 kt late. Seas
3 ft in the evening, then 2 ft or less.
.SUN...Winds light and variable. Seas 2 ft or less. 
.SUN NIGHT...Light winds. Seas 2 ft or less. 
.MON...S wind 10 kt. Seas 2 ft or less. 
.MON NIGHT...N wind 15 kt. Seas 3 ft. 
.TUE...NW wind 15 kt. Seas 3 ft. 
.WED...N wind 10 kt. Seas 2 ft or less. 
.THU...NW wind 10 kt becoming SE. Seas 2 ft or less. 

$$

PKZ012-251645-
Northern Lynn Canal-
354 PM AKDT Sat Apr 24 2021

.TONIGHT...N wind 15 kt. Seas 3 ft. 
.SUN...N wind 10 kt in the morning becoming light. Seas 2 ft
or less. 
.SUN NIGHT...Light winds becoming N 10 kt late. Seas 2 ft or
less. 
.MON...SE wind 15 kt. Seas 3 ft. 
.MON NIGHT...N wind 15 kt. Seas 3 ft. 
.TUE...N wind 20 kt. Seas 4 ft. 
.WED...N wind 15 kt. Seas 3 ft. 
.THU...N wind 15 kt becoming SE. Seas 3 ft. 

$$

PKZ013-251645-
Southern Lynn Canal-
354 PM AKDT Sat Apr 24 2021

.TONIGHT...N wind 15 kt. Seas 3 ft.
.SUN...N wind 10 kt in the morning becoming light. Seas 2 ft
or less. 
.SUN NIGHT...Light winds. Seas 2 ft or less. 
.MON...S wind 10 kt. Seas 2 ft or less. 
.MON NIGHT...N wind 15 kt. Seas 3 ft. 
.TUE...N wind 20 kt. Seas 4 ft. 
.WED...N wind 15 kt. Seas 3 ft. 
.THU...N wind 15 kt becoming S. Seas 3 ft. 

$$

PKZ021-251645-
Icy Strait-
354 PM AKDT Sat Apr 24 2021

.TONIGHT...W wind 10 kt, except NE 15 kt west of Point Adolphus. 
Seas 3 ft.
.SUN...W wind 10 kt in the morning becoming light. Seas 2 ft
or less. 
.SUN NIGHT...E wind 10 kt becoming light. Seas 2 ft or less. 
.MON...W wind 10 kt. Seas 2 ft or less. 
.MON NIGHT...E wind 15 kt. Seas 3 ft. 
.TUE...E wind 15 kt. Seas 3 ft. 
.WED...E wind 15 kt. Seas 3 ft. 
.THU...SE wind 10 kt. Seas 3 ft. 

$$

PKZ022-251645-
Cross Sound-
354 PM AKDT Sat Apr 24 2021

.TONIGHT...NE wind 15 kt. Seas 6 ft. 
.SUN...E wind 15 kt in the morning becoming light. Seas 5 ft. 
.SUN NIGHT...Light winds becoming W 10 kt late. Seas 4 ft. 
.MON...W wind 10 kt. Seas 5 ft. 
.MON NIGHT...E wind 20 kt. Seas 5 ft. 
.TUE...E wind 25 kt. Seas 6 ft. 
.WED...E wind 15 kt. Seas 6 ft. 
.THU...E wind 15 kt. Seas 5 ft. 

$$

PKZ031-251645-
Stephens Passage-
354 PM AKDT Sat Apr 24 2021

.TONIGHT...NW wind 15 kt. Seas 3 ft.
.SUN...N wind 10 kt in the morning becoming light. Seas 2 ft
or less. 
.SUN NIGHT...Light winds. Seas 2 ft or less. 
.MON...SE wind 10 kt. Seas 2 ft or less. 
.MON NIGHT...SE wind 15 kt. Seas 3 ft. 
.TUE...NE wind 15 kt. Seas 3 ft. 
.WED...SE wind 15 kt. Seas 3 ft. 
.THU...S wind 15 kt. Seas 4 ft. 

$$

PKZ032-251645-
Northern Chatham Strait-
354 PM AKDT Sat Apr 24 2021

.TONIGHT...N wind 15 kt. Seas 3 ft. 
.SUN...N wind 10 kt in the morning becoming light. Seas 2 ft
or less. 
.SUN NIGHT...N wind 10 kt in the evening becoming light. Seas
2 ft or less. 
.MON...Light winds. Seas 2 ft or less. 
.MON NIGHT...SE wind 15 kt. Seas 3 ft. 
.TUE...NE wind 15 kt. Seas 3 ft. 
.WED...SE wind 15 kt. Seas 3 ft. 
.THU...S wind 15 kt. Seas 3 ft. 

$$

PKZ033-251645-
Southern Chatham Strait-
354 PM AKDT Sat Apr 24 2021

.TONIGHT...N wind 15 kt. Seas 3 ft.
.SUN...N wind 15 kt. Seas 3 ft. 
.SUN NIGHT...N wind 10 kt in the evening becoming light. Seas
2 ft or less, except 4 ft near ocean entrances. 
.MON...Light winds. Seas 2 ft or less, except 4 ft near ocean
entrances. 
.MON NIGHT...S wind 10 kt. Seas 2 ft or less, except 5 ft near
ocean entrances. 
.TUE...NE wind 15 kt. Seas 3 ft. 
.WED...SE wind 15 kt. Seas 3 ft. 
.THU...S wind 15 kt. Seas 3 ft. 

$$

PKZ034-251645-
Frederick Sound-
354 PM AKDT Sat Apr 24 2021

.TONIGHT...E wind 10 kt. Seas 2 ft or less. 
.SUN...E wind 10 kt in the morning becoming light. Seas 2 ft
or less. 
.SUN NIGHT...Light winds. Seas 2 ft or less. 
.MON...E wind 10 kt. Seas 2 ft or less. 
.MON NIGHT...E wind 10 kt. Seas 2 ft or less. 
.TUE...E wind 20 kt. Seas 4 ft. 
.WED...E wind 15 kt. Seas 3 ft. 
.THU...E wind 20 kt becoming S. Seas 4 ft. 

$$

PKZ035-251645-
Sumner Strait-
354 PM AKDT Sat Apr 24 2021

.TONIGHT...E wind 10 kt. Seas 2 ft or less. 
.SUN...E wind 10 kt. Seas 2 ft or less. 
.SUN NIGHT...E wind 10 kt in the evening becoming light. Seas
2 ft or less, except 4 ft near ocean entrances. 
.MON...Light winds. Seas 2 ft or less. 
.MON NIGHT...SE wind 10 kt. Seas 2 ft or less. 
.TUE...E wind 15 kt. Seas 3 ft. 
.WED...E wind 15 kt. Seas 3 ft. 
.THU...S wind 15 kt. Seas 3 ft. 

$$

PKZ036-251645-
Clarence Strait-
354 PM AKDT Sat Apr 24 2021

.TONIGHT...NW wind 10 kt. Seas 2 ft or less. 
.SUN...NW wind 10 kt. Seas 2 ft or less. 
.SUN NIGHT...NW wind 10 kt. Seas 2 ft or less. 
.MON...S wind 10 kt. Seas 2 ft or less. 
.MON NIGHT...S wind 10 kt. Seas 2 ft or less, except 5 ft near
ocean entrances. 
.TUE...SE wind 20 kt. Seas 5 ft. 
.WED...SE wind 20 kt. Seas 5 ft. 
.THU...S wind 20 kt. Seas 5 ft, except 7 ft near ocean entrances.

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
503 AM AKDT Sat Apr 24 2021

.SHORT TERM...The forecast has had minimal changes done to it this
morning. Clear and dry remain the short and sweet forecast,
however changes are looming and can be seen in the minor
alterations of the upper level pattern through the weekend.
Temperatures will be similar today compared to yesterday with
highs above normal highs and the lows below the normals for the
day. The dry air over Southeast Alaska is allowing for a wider
diurnal range.

The closed high over the interior of the state is weakening back
into a narrowing upper ridge from the eastern gulf into the
interior of the state by late Sunday night. A pair of upper
troughs will, starting late Sunday, will be advancing on the ridge
to wear it down. The second trough is moving about an upper level
low that is anchored over northern Canada west of Hudson Bay.
Will need to keep an eye these trough over the next few forecast
cycles to see how they will interact with each other.

Winds primarily under 20 kt for the marine areas with the
'windiest' area being Lynn Canal. Forecast confidence remains
above average through the weekend.

.LONG TERM.../Mon through Sat as of 10 pm Fri/ Little in the way
of changes compared to the previous forecast for the upper level
pattern through next week. Still looking at a pair of upper lows
replacing the upper high that has dominated the area over the last
week or two.

For the panhandle, that means increasing confidence in a more
active scenario starting up Tue into Thu as a pair of fronts
advance on the area. Front number one takes aim at the southern
panhandle Tue and will try to make headway farther north into Wed.
However, there is an upper level short wave dropping down from
the north at the same time bringing cooler air and higher surface
pressures to the southern Yukon (with the possibility of some of
that spilling over the coast mountains). Guidance is handling how
much effect this short wave has on the incoming front
differently. Some are stalling the front over the central
panhandle, while others (the majority) show a brief stall before
northward movement resumes to get the rest of the panhandle wet on
Wed. In either case the southern panhandle gets wet with some
breezy conditions Tue into Wed regardless so higher pops and QPF
expected there while for the north we are going with likely pops
and lower QPF to reflect the uncertainty still present. Another
factor that could result in lower possibilities and/or amounts of
rainfall for the north is the weak outflow that will be going on
at the time both from the upper short wave that is dropping in
from the north and the orientation of the front coming up from the
south. This may result in a drier airmass in the area that could
make precipitation difficult at least initially on Wed for the
north.

Farther out, the panhandle will see another front moving up from
the south to replace the first one with most guidance trending
wetter for most of the panhandle by Thu. This feature is looking
more moisture laden then the first one and integrated vapor
transport guidance shows the possibility of a minor to mod
atmospheric river aimed at the southern panhandle at that time
(though briefly). However, timing and placement of the front is
still in flux at this time and though the presents of
precipitation in the area seems rather certain at this time the
intensity of it (as well as the timing of when that intensity will
be the highest) is average confidence at best. We will continue to
refine the forecast as we get closer.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.

&&

Bezenek/EAL

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