Area Forecast Discussion Issued by NWS Juneau, AK
000
FXAK67 PAJK 261329
AFDAJK
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
529 AM AKDT Tue Sep 26 2023
.SHORT TERM...Widespread precipitation will return to the
panhandle through Tuesday as a decaying occluded low currently
located west of Haida Gwaii slowly moves N. Although fog formed
during the overnight hours across parts of panhandle within a
clearing between frontal bands, with a few areas even seeing a
dense fog advisory through parts of the morning time frame, it
will prove to be short-lived. Precipitation has already begun
across the southern half of the panhandle - alongside lowering
cloud decks and increasing winds. The remainder of the area will
see rain moving in through the rest of the morning and afternoon
hours with the exception of Yakutat, which will avoid most of the
precip. At this time, am not expecting any significant flooding
concerns with this system, although some river rises are possible.
Although the low itself will weaken as it moves N, strong winds
over many land-based locations are still expected, particularly
across the southern panhandle. Small craft conditions are
anticipated for many of the outer coastal waters and central and
southern inner channels, alongside Lynn Canal. Gale force winds
are anticipated in Clarence Strait, as well as some of the outer
coastal waters. Temperatures will reach the upper 50s through the
day, with upper 40s or lower 50s expected for most locations near
sea level Tuesday night.
.LONG TERM.../Wednesday through Monday/...Continuing from the
short term, winds along the southern inner channels and outer
coast will begin to diminish by Wednesday afternoon/evening as
the low moves northward and continues to weaken and elongate. This
will allow rain showers to persist over a majority of the
panhandle through the day Wednesday with diminishing chances by
Thursday morning. The rate at which this system weakens and
dissipates is still uncertain, though by Friday showers should be
few and far between with the potential for clearing due to the
influence of a ridge pushing through from the south ahead of the
next system.
Heading into the weekend, conditions continue to look typical of
fall for SE Alaska with temperatures remaining mild to cool and
rain not off the table Friday, as of this forecast. Long range
models are then beginning to show the potential for a strong low
to move in from the northern pacific and push a gale force front
into the panhandle sometime Saturday into Sunday. EFI tables are
also trending upwards suggesting this could be another moderate to
heavy rain event, however uncertainty remains as to the duration
of this rain as well as the propagation of the front and
associated plume of moisture. Stay tuned for further updates
throughout the week as we monitor this system through the mid
range forecast period.
&&
.AVIATION.../Until 12Z Wednesday/...A low poised south of the
area will slowly approach the southern Panhandle through the TAF
period. A series of waves orbiting it will bring decent chances of
rain and breezy conditions, especially to the southern half of the
Panhandle. The break in the clouds and light winds between the waves
will cause patchy radiation fog formation over portions of the
central and northern Panhandle like Gustavus, Juneau, Hoonah,
Angoon, & Yakutat into Tuesday morning. Gusty SFC winds over the
southern Panhandle and LLWS magnitudes over that same area of up to
around 35 to 50 kt out of a southeasterly direction are possible
during the TAF timeframe associated with the approaching low and
associated waves.
&&
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Dense Fog Advisory until 8 AM AKDT this morning for AKZ324.
Strong Wind through late tonight for AKZ328-330-332.
MARINE...Gale Warning for PKZ036-641-661-662.
Small Craft Advisory for PKZ031-033>035-642>644-651-652-663-664-
671-672.
&&
$$
SHORT TERM...GFS
LONG TERM....STJ
AVIATION...JLC
Visit us at http://www.weather.gov/Juneau