245
FXAK67 PAJK 031729
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
929 AM AKDT Sun Aug 3 2025

.UPDATE...
18z Aviation Discussion update.

&&

.PREV DISCUSSION......ISSUED AT 0537am...

SHORT TERM...An embedded low bringing precipitation across the
panhandle this morning is expected to move through a bit quicker
than previously expected. PoPs have been updated to show the trend
of this moisture moving through quicker and remaining more to the
south and further inland today. The highest potential for
precipitation remains inland in the southern panhandle with parts
of the central and northern panhandle dropping from likely to
chance of precipitation by this afternoon. Chances remain across
the majority of the panhandle until some showers are expected to
move into the northern panhandle from Canada later tonight,
increasing precipitation chances around Skagway and Haines. QPF
has largely remained the same despite this system moving through
quicker, with between 1.0 and 1.5 inches in 24 hours for the
southern panhandle, 0.5 to 0.75 inches in 24 hours for the central
panhandle, and only 0.15 to 0.3 inches in 24 hours expected for
the northern panhandle. Overall expecting moderate to heavy rain
for some parts along the southern and central panhandle, with
light rain across the rest of the panhandle as this wave of
moisture moves through.

Most of the wind concerns for today will be for the inner
channels and Gulf coastline as the shortwave moves through, while
being less impactful for most areas inland outside of possible
gusty conditions during showers. The only exception will be the
town of Skagway, which will begin to see some 15 to 20 kt winds
this afternoon into tonight as the pressure gradient to the north
tightens from a low over the Yukon Territory to the north.

LONG TERM... The remains of the frontal band moving through the
panhandle with higher pops that will be tapering off to chance by
late Tuesday afternoon. Wednesday is looking dry and that
continues to into Thursday. The dry weather is due to a ridge
moving across the eastern gulf and to the panhandle. Along with
this ridge, 850 mb temperatures are going to increase, in turn,
increasing temperatures at the surface. Above normal temperatures
are expected mid to late week. The NBM is showing maximum
temperatures in the low to mid 70s for many areas across the
panhandle.

Next weekend, a strong low over the western gulf and eastern
Bering Sea, moves towards the western Gulf. A front from that low
swings across the North Pacific and then into Western gulf and
toward the panhandle. With that low, there are starting to be
indications of a plume of moisture that is increasing IVT values
across the southern gulf. These higher IVT values reaching > 250
to 500 kg/m*s shows the chance of AR development. If this occurs,
we can see moderate to heavy rain over parts of the panhandle.
Currently this increase in moisture looks to be focused on
northern areas. We will continue to monitor the strong low and the
associated potential for heavy precipitation.

AVIATION...18z update.
A broad low stationary in the gulf over the last several days is
moving ashore this afternoon, bringing rain showers to the region
with MVFR in the central and southern Panhandle. Dynamics
associated with this feature, and cooler temperatures aloft, will
help drive instability Sunday afternoon leading to deeper
convection, largest threat will be reduction of conditions from
VFR to MVFR from VSBY of 3SM, CIGS AoB FL025, and RA BR. Higher
confidence for these heavier showers/TCU south of Frederick Sound.
By early Monday morning we anticipate MVFR to IFR from CIGS AoB
FL020 for most of the region, BECMG VFR by late morning.


MARINE...
Outside Waters: The embedded low moving up the eastern gulf this
morning continues to bring increased winds along the coast between
15 kt and 20 kt as the shortwave moves through. This will continue
to have a diminishing trend by the afternoon to predominantly 10
kt or less as the low weakens. Some areas of 15 kt winds will
remain coming out from Cross Sound until this afternoon, and some
increased winds west of Haida Gwaii later tonight as a low
approaches in the southern Gulf. Seas of 4 to 5 ft are expected
today into tonight. SW to W swell with wave period of 13 to 15
seconds expected.

Inside Waters: Some increases to 15 to 20 kt throughout the inner
channels as the shortwave moves through this morning, with
locations in Clarence Strait and near the ocean Entrances already
seeing winds around 15 kt. These increases to the winds will not
last, however, with most of the inner channels diminishing to
around 10 kt throughout the day once the shortwave passes. Problem
areas around Ship Island, Five Finger Islands, Rocky Island, Scull
Island, and Eldred Rock will likely remain closer to 15 kt for a
bit longer into the afternoon/evening as the shortwave moves
northward over the panhandle. Lynn Canal will stay increased at
around 15 kt from this afternoon into tonight as the pressure
gradient tightens over the northern panhandle due to a low
to the north over the Yukon Territory. Otherwise, the majority of
the inner channels are expected to return to calmer conditions
less than 10 kt as the low weakens offshore and dissipates by
later tonight.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.

&&

$$

SHORT TERM...STJ
LONG TERM....Bezenek
AVIATION...AP
MARINE...STJ

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