430
FXAK67 PAJK 051739
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
939 AM AKDT Sun May 5 2024

.UPDATE...Update to aviation discussion to include the 18z TAF
issuance.

&&

.SHORT TERM...Satellite imagery and surface analysis depict low
pressure system over the SW gulf with an occluded boundary across
the NE gulf coast stretching SE just off the outer coast early
this morning. Sat derived rain rates indicate precip over much of
the panhandle early this morning, but with the relatively dry BL,
reports have been mainly limited to the NE gulf coast overnight.
Precip has spread into the Icy Strait corridor attm and expect BL
to continue saturate with precip becoming more widespread through
the early morning. Precip will persist through the day with
rainfall totals ranging from 0.25-0.75" through Mon morning.

.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.

&&

.AVIATION...This morning, periods of MVFR conditions are being
reported as the band of rain tracks northward. Behind the front,
isolated periods and areas of MVFR are possible where the rain
showers are, but overall, VFR conditions should return to SE AK
this afternoon with VFR lasting into tonight.

&&

.MARINE...Generally light to gentle southerly breezes over the
inner channels this will become moderate to fresh southerlies Sun
morning and persist into the evening before diminishing. Over the
gulf, fresh E to SE winds will prevail with a SW swell building
combined seas to 8-10ft tonight. Conditions will ease Mon into Tue
before deteriorating Tue into Wed as another low moves into the
gulf bringing near gales to gales over the gulf along with
building seas. Inner channels will see fresh to strong winds in
response to the tightening pressure gradient.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ641>644-651-652-661>664-671-672.

&&

$$

SHORT TERM...BC
LONG TERM....GFS
AVIATION...GJS
MARINE...BC

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