400
FXAK67 PAJK 041339
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
539 AM AKDT Sat May 4 2024

.SHORT TERM...Satellite imagery and surface analysis show a weak
front pushing into the NE gulf coast with the parent low still W
of AK peninsula. Models remain in good agreement with precip
chances increasing N to S through the day. Expect precip to start
over the NE gulf late this morning/early afternoon and spread E
and S overnight into Sunday. Changes to the forecast were to
adjust mass fields to current observations.

.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...VFR to MVFR conditions expected through the TAF
period with BKN to OVC cigs increasing today ahead of an
approaching system. Precipitation chances increase for PAYA by 18z
this afternoon, slowly trending eastward towards the rest of the
southeast TAF sites by 12z Sunday. Winds should remain 10kts or
less with isolated sustained winds up to 15kts possible.

&&


.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Frost Advisory until 9 AM AKDT this morning for AKZ319>321-325.
MARINE...None.

&&

$$

SHORT TERM...BC
LONG TERM....GFS
AVIATION...NM

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