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FXAK67 PAJK 032304
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
304 PM AKDT Fri May 3 2024

.SHORT TERM.../Through Saturday night/...The short range forecast
will feature a changing weather pattern for Southeast Alaska.
After a nice stretch of mostly dry and slightly warmer than normal
Spring weather, a front will approach from the west on Saturday,
spreading east and south through Saturday night. For some SEAK
locations, this will be the first measurable precipitation in well
over a week. Saturday`s daytime highs and overnight lows will likely
be the warmest of this dry spell, but that will change with a return
of the clouds and rain and heading into the medium range forecast
period. Even so, overnight temps tonight still warrant a frost
advisory for much of the northern Panhandle.

.LONG TERM...An active weather pattern returns in full swing to SE
AK 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 will sharply depart 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 move 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. The first wave, on Sunday, will be
associated with an occluding system moving out of the NW which
will cross the Gulf and dissipate over the panhandle, but not
before bringing with it a return to more abundant precipitation.
For more information on this system, refer to the short term
forecast discussion. Lingering chances of precipitation associated
with onshore flow 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.

This will bring temperatures more in lockstep with normal values
as high temperatures return to the 50s, in departure of the 60s
enjoyed during the previous week. The main changes to the forecast
were significant increases in wind speeds and wave heights, along
with some refinement to the QPF forecast, though exact timing for
these remains difficult to precisely determine this far out.
Likewise, increased PoP chances through the second half of the
upcoming week given the growing agreement between operational
models on at least two systems arriving after the Sunday system.
Minor changes were made to temperatures and cloud cover. Minor
adjustments made to temperatures to capture the diminished diurnal
trends.


&&

.AVIATION...Another day of VFR conditions today and tonight with
some increasing cloud cover overnight and into late Saturday. CIG
expected to be above 5k. Offshore and northerly flow with sea breeze
activity continue with no LLWS issues expected.

&&

.MARINE...Winds remain rather light and the northerly 15 to 20
kts experienced over Lynn Canal and Stephens Passage have already
eased as of early this afternoon and are not expected to return
tomorrow or tomorrow night. On the outside, pre-frontal winds
expected to be 20 kts or less, even near the coast west of Icy Bay
where barrier jet enhanced winds typically form. Based on present
combined sea heights being reported by the offshore moored buoy
network, the short term sea state forecast was diminished slightly
to below small craft criteria, so no marine hazards have been
included with the afternoon forecast issuance.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Frost Advisory from 1 AM to 9 AM AKDT Saturday for AKZ319>321-
     325.
MARINE...None.

&&

$$

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

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