Shipley Lake, Alaska Weather Forecast Discussion

494
FXAK67 PAJK 020548 AAA
AFDAJK
Southeast Alaska Forecast Discussion...UPDATED
National Weather Service Juneau AK
948 PM AKDT Wed Oct 1 2025
.UPDATE...Aviation section updated for 6z taf issuance.
&&
SHORT TERM...
Clearer skies, with some upper level cloud cover, will linger
across areas East of Yakutat through the overnight, setting the
stage for low temperatures to reach into the 30s across much of
the area, with below-freezing weather expected for many locations
- especially across the Icy Strait Corridor.
The break in the autumn pattern comes to a close through Thursday
as another system enters the panhandle. While the morning hours
on Thursday will still be largely on the drier side (except in
Yakutat), through the afternoon and evening hours, rain spreads
from NW to SE across the area. The track of the system`s parent
low, which dives NW out of the interior, would during winter
normally herald the arrival of a snow producing system. Given that
this is only early October, anticipate it be primarily a rain
event for most locations, although snow levels dropping down to
3,500 to 4,500ft will open up the opportunity for the termination
dust line to continue to work down the mountainside, especially
for the northern panhandle. The possibility of snow mixing down to
White Pass is possible and could result in a dusting to minor
accumulations for this area, particularly during heavier periods
of precipitation Thursday into Friday. Everywhere below 3,000ft is
expected to continue to see rain.
LONG TERM...
Friday begins just as a quick moving front moves off to the east
southeast, with copious ridging behind the front. WAA from 850-500
mb will help to strengthen the ridge, with 500 mb heights
reaching well above climatology for this time of year. With modest
onshore flow, not expecting much clearing with the exception of
around 6 hours post front, or Friday morning, but will definitely
result in reduced rain chances through Saturday morning. For winds
during Friday and Saturday, kept the southerly portion of the
panhandle behind the front mostly westerly to 10 knots at a
maximum, however, many areas will see lighter winds. The northern
end of the panhandle have a much higher likelihood (60% chance) to
see wind speeds from the south exceed 15 knots for longer, mostly
driven by leeside troughing from westerly wind aloft moving over
the Coast Mountains and troughing in the interior of Canada.
Chances diminish into the evening hours of Friday before picking
up again Sunday.
Sunday enters the uncertain portion of the forecast, as ensemble
guidance has the highest spread regarding how fast a new upper
trough will break down the currently set ridge during this time
range. The main source of uncertainty is actually in regards to a
strong low moving into the Bering Sea, which will have downstream
implications for breaking down the ridge. A weaker system will
keep a more progressive forecast, bringing more rain faster into
the panhandle proper, with a stronger system deepening the trough,
strengthening the downstream ridge, and keeping rain over Yakutat
longer. Therefore, there are wide gates over Yakutat for how much
rain to expect, with a higher likelihood (50%) between 1.5 and
3.5 inches in 48 hours, but lower chances (less than 15%) of
exceeding 5 inches in the same duration.
AVIATION.../through 06z Friday/
VFR conditions and lighter winds rule the panhandle this evening,
but change is coming. A front will be rolling in from the west
later tonight through Thursday night bringing rain and some winds
to the area. Yakutat will see the changes first with ceilings and
vis dropping to MVFR by 14z due to rainfall moving in. The
northern inner channels will start to see rain with lowering
ceilings and vis to MVFR around mid morning to midday. The front
will take some time to get to the southern panhandle as it fights
the ridge over the area, but rain should start to move into that
area by Thursday evening with the accompanying reduction in
ceilings and vis. Winds will also be on the increase, however max
winds will not occur for most areas until Thursday afternoon
(Yakutat) to Thursday night (rest of the panhandle) with max gusts
reaching 30 to 35 kt in some areas. Some low level wind shear
(mainly speed shear with 2000 ft agl winds reaching 30 to 35 kt
out of the SE) and turbulence may also be present during the
period of higher winds.
MARINE...
Outside: Through Wednesday night, the current NW flow pattern
shifts to a more SW direction as the ridge over the panhandle
breaks down and a front begins moving into the Gulf. Through
Thursday and Thursday night, winds turn out of the S as the front
moves into the area, with winds of 25 kt to 30 kt anticipated for
most areas, and gales (35 kt) for the far northern Gulf. Wave
heights rebuild across the area, reaching 12-15 feet Thursday
night for areas south of Cape Spencer, and 7-9 feet for areas
north of Cape Spencer. Swell is currently of the S to SE, but by
Thursday night, will be switching to SW.
Inside: Winds in the central and northern inner channels flip to
a more S direction through Wednesday night, with winds in the
southern channels following suit through the day on Thursday.
Winds during the daytime hours on Thursday build to 15 t o20 kt,
reaching 20 - 30 kt Thursday night as a front moves through. Wave
heights increase on Thursday to 3-4 feet, and Thursday night up to
4 to 6 ft, with higher heights at ocean entrances and in areas
with local tidal currents and influences (like Point Couverden).
&&
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gale Warning for PKZ652.
     Small Craft Advisory for PKZ012-022-643-644-651-661>664-671-672.
&&
$$
SHORT TERM...GFS
LONG TERM...NC
AVIATION...EAL
MARINE...GFS
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NWS AJK Office Area Forecast Discussion