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FXAK67 PAJK 050709 CCA
AFDAJK

Southeast Alaska Forecast Discussion...CORRECTED
National Weather Service Juneau AK
1109 PM AKDT Sat May 4 2024

.SHORT TERM...
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/Through Sunday night/...Rain has returned to
Southeast Alaska after a nice stretch of fine Spring weather.
An overcast moved over the northeast gulf coast overnight and rain
began in Yakutat around 8 am. Overcast conditions have been
spreading south and east in advance of the front & rain with only
locations south of Frederick Sound under nothing more extensive
than a thin, high cirrus layer as of mid day. By tomorrow morning,
all but the far northern inner channels and the southern outer
coast should be back in the rain. Sunday through Sunday night
should see at least periods of rain across the vast majority of
Southeast Alaska. The cloud cover will result in an increase in
overnight lows and a decrease in daytime highs for this short
term forecast period, which is not surprise. This will also
obviate the need for another frost advisory. Winds over land will
not be impactful either.


.LONG TERM...An active weather pattern continues as system after
system moves into the panhandle, with each one bringing concurrent
chances of rain and wind across the area.

Aloft, the upper level pattern has sharply departed from its
previous state of the past few weeks. The primary steering flow
which was directing systems to the south and away from the
panhandle will instead be directly overhead as a strong jet
streak developing along the E flank of a deepening trough over the
Bering Sea moves the primary area of upper level support over the
panhandle.

Closer to the surface, this will enable multiple waves to develop
and enter the panhandle. Lingering chances of precipitation
associated with onshore flow in the wake of a system from Sunday
will remain through Tuesday before another, stronger system
arrives later on Tuesday or Wednesday. This second system will
move up from the SW, moving around the broader area of upper level
troughing. Expect a surge of more widespread precipitation to be
possible with this system alongside the potential for small craft
winds for many locations and gale force winds potentially in the
gulf. Beyond this point operational guidance begins to falter as
model spread grows, but ensembles are indicative of another system
arriving immediately in the wake of the previous one, delivering
another round of rain and wind to SE AK, with the active weather
pattern likely to continue thereafter.

The primary changes to the forecast for next week were centered
around adding additional detail to the wind forecast, as timing is
slowly beginning to come into better agreement. Some changes to
the QPF forecast were made as well, based on better consensus
regarding the arrival of the main bands of precipitation across
the panhandle.
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&&

.AVIATION...Our extended period of VFR is gradually coming to an
end here in SE Alaska as a front moves in from the west tonight
bringing widespread rain and lower ceilings to much of the region
Sunday. MVFR will be moving into Yakutat over the next 6 hours
with IFR late tonight when the main area of rain moves in (lower
ceilings). Otherwise, we will trend airports down to MVFR through
late tonight into daybreak tomorrow for all except Ketchikan which
will more likely hang on to VFR into the afternoon Sunday before
dropping to MVFR as the more widespread rain moves in.

&&

.MARINE...
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Winds on the inside will be marginally impactful with
localized winds to 20 kts. Seas 4 ft or less. On the outside,
pre-frontal winds around 20 kts are expected with a small region
of 25 kt small craft winds west of Icy Bay this evening. Winds
will diminish to 10-15 kts and shift to the southwest post
frontal. Combined seas 5-6 ft through the night, but a
southwesterly long period swell of 8-9 ft will build in towards
the outer coast on Sunday night.
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&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ652-672.

&&

$$

SHORT TERM/MARINE...Fritsch
LONG TERM....GFS
AVIATION...JG

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