591
FXAK67 PAJK 242352
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
252 PM AKST Fri Jan 24 2025

.SHORT TERM...Good news, synoptic flow pattern continues to
progress as previously forecast with high pressure building into
the gulf, shielding SE AK from any significant surface systems.
Bad news, the originally advertised drying trend proved to be a
bit too optimistic. Northwesterly flow aloft rotating over the
northern edge of the ridge is still transporting enough moisture
in the mid to upper levels to maintain higher level cloud cover.
In addition, a marine layer has formed and pushed in at lower
levels due to the persistent onshore flow and is being maintained
by the moisture and subsequent inversion or relatively isothermal
profile above it in many areas. As a result, the northern and
central panhandle has seen drizzle and occasional light rain
showers through the day Friday and will see that continue Friday
night into Saturday, with flurries possible at higher elevations.
Due to this continued saturation, protected areas will see patchy
fog development as well, similar to Thursday night. By Saturday
night, the ridge in the gulf is expected to shift further
eastward, allowing for light to moderate precipitation to flow
into the area of Yakutat and further increase chances for rain
showers across the panhandle from Icy Strait northward.

The far southern panhandle has the best chance of clearing out
overnight with light winds continuing out of the NW. Along the
gulf coast of PoW though this flow pattern will likely keep the
marine layer in the area, ebbing and flowing through the day
Saturday.

.LONG TERM...Quick Notes:


/Saturday to early next week/...
Quick notes:
-Ridge of high pressure will be in place this weekend before
breaking down early next week.
-Precip chances (mainly rain) will spread southward Sunday into
Monday as the ridge breaks down.
-Continued warmer-than-normal temps before a cooling trend settles
in by mid-week.

Details:

Lots of agreement in the models over the big picture idea.
Going into the weekend, a ridge of high pressure will be over the
gulf and panhandle. This should bring some drier weather to the
southern half. The northern half of SE AK looks to have some rain
riding the northern edge of the ridge, which would keep the clouds
and rain in the forecast.

Sunday into Monday rainfall amounts will be impressive for Yakutat,
where 24 hour rainfall amounts around 1.5 to 2 inches are likely.
EURO and GFS ENS probabilities are about 70% chance of amounts
greater than 1 inch, and near 30 to 40% chance of greater than 2
inches.

Monday looks similar for amounts near Yakutat but the rain spreads
into the rest of the panhandle. Sumner Strait and north look to get
about 0.5 to 0.75 inches of qpf with areas south of Sumner Strait
getting less than a half inch. Probabilities of getting more than
0.5 inches is around 60 to 80% with probabilities of getting more
than 1 inch are less than 20%.

As the ridge breaks down, the heavier precip will slide southward.
But 24 hour amounts look to be up to a half inch for those north of
Frederick Sound, less than a quarter inch for those south of
Frederick Sound.

Otherwise, this weekend will have warm temps for late January with
generally light winds over land areas. Winds in the inner channels
look to be around 5 to 15 knots. Stronger winds, around 15 to 20
knots, look to be in Lynn Canal. Sunday night into Monday, wind
speeds will increase with all inner channels will range from 10 to
25 knots.

&&

.AVIATION...The high pressure in the Alaskan Gulf continues to
bring onshore flow. This is creating a marine layer that is
lowering ceilings and visibilities. Above this marine layer are
high ceilings with breaks in the clouds. This marine layer is
going to keep ceilings around MVFR down to LIFR and visibilities
down to IFR. Any diminishing of the marine layer will greatly
improve ceilings and visibilities to VFR. With the positioning of
the high pressure, the marine layer and these variable conditions
are expected to persist. Yakutat and the southern panhandle will
be the most likely to see a break from this marine layer to have
VFR conditions with potentially clear skies.

&&

.MARINE...Pattern continues to progress as previously forecast.
For the Gulf: Swell continues to diminish, remaining from the
west, as a series of storms impact the AK peninsula towards Prince
William Sound. As high pressure persists in the eastern gulf,
expect northwesterly strong breezes along the coast, with the
highest winds from Cape Fairweather south towards Cape Ommaney.
Main wave energy continues to be west- southwest with heights
dropping below 11 ft through Friday night. Expect heights to
increase past 15ft along the northern coast by late Saturday night.

Inner channels: Onshore flow continues from high pressure in the
eastern gulf, with fresh to strong breezes the main focus for
inner channels. Cross Sound will continue to see the strongest
winds, accelerating around Cape Spencer with small craft
conditions persisting into Saturday. West to southerly winds from
Frederick Sound north to Lynn Canal, and west to northerly winds
building in Sumner Strait south through Clarence Strait.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ021-022-053-641>644-651-652-661>664-
     671-672.

&&

$$

SHORT TERM...STJ
LONG TERM....GJS
AVIATION...EAB
MARINE...STJ

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