Gale Warning 87, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
612 AM AKST Tue Feb 25 2025

.SHORT TERM...Clouds and light precipitation continue to affect
the Panhandle Tuesday as the remnants of the previous low move
out of the area. A trough in the Gulf sets up for another
developing system to track northward through the central Gulf
Tuesday night, bringing periods of rain with the highest totals
over the Southern Panhandle. Along the Haines Highway, increased
moisture combined with cold temperatures aloft will yield
advisory level snowfall through the morning. Webcams and mesonet
data show an attempt to transition to liquid, but we expect
cooler temperatures to persist supporting additional accumulation.

.LONG TERM.../Wednesday through the weekend/ The upper level jet digs a trough
down into the western gulf on Tuesday with S-SWLY flow increasing
over the eastern gulf and the panhandle. This will cause a new low
center to develop at the surface as it tracks northward into the
central Gulf of Alaska Tuesday night through Wednesday. Expect gale
force winds of 35 to 45 knots over the outside waters. Winds through
the northern/central inside waters will turn out of the north ahead
of the low pressure, then shift to the south-southwest after the
front passes. Rainfall amounts with this system looks to range from
1-3 inches with around a 6hr period of moderate to heavy rates.
Freezing levels were raised slightly along the northern border,
nullifying significant snow accumulations for Haines Highway. For
the Klondike Highway, however, fully saturated layer combined with a
profile below freezing will lend to snow develop. The main question
at this point is the present lifting mechanisms, as the front may
shear and weaken before reaching this area. So while moisture may be
present, the lack of upward forcing may limit snow rates. Went with
solutions with more aggressive with cold air intrusion aloft,
which will increase lapse rates in the dendritic growth zone.
Given the possibility and 50% confidence of occurrence, issued a
winter storm watch for the Klondike Highway.

Beyond the initial, impactful front to pass over the panhandle, the
low center's future remains more uncertain. Ensemble means of the
GEFS and GEPS as well as operation ECMWF lean toward the low center
moving near Yakutat with good agreement. However, the operational
GFS, Canadian, NAM, and ensemble EPS seem to indicate the low center
breaking away from the jet aloft and drifting west of Prince William
Sound. Current forecast represents the low moving into/slightly east
of Prince William Sound, which would result in strong breezes along
the NE gulf from a minor barrier jet.

After a short break, the next gale force front looks to track in
from the west Thursday night into Friday. This system brings in more
swell and seas building to 20ft over the gulf on Friday. The jet
stream looks to direct the moisture to the southern panhandle on
Thursday, then wavers south of the area on Friday. Therefore this
could be a relatively quickly passing system. Heading into next
weekend, there are some signs of brief ridging in the gulf which
would give us another break (something to look forward to).

&&

.AVIATION...This morning brings a brief clearing of conditions to the northern
panhandle as the low pressure system moves onshore and dissipates.
The rest of the panhandle will see some lingering low ceilings and
drops in visibility due to persisting rain and fog. The southern
panhandle will see more lasting MVFR conditions into the day with
some drops to IFR as the remnants of the front are still pushing
through from the south. As the system has started to move out of the
northern panhandle, Haines and Skagway have started gusting between
20 and 25kts and are expected to stay gusty through tonight.
Ceilings and visibility are expected to drop again as the next
system moves in tonight and brings more rainfall to the panhandle.
Our main aviation concern going into tonight is wind shear
stretching from Dixon Entrance through Icy Strait corridor,
including Juneau. The wind shear is expected to start up late
tonight, with wind speeds of 35 to 45kts at 2000ft, with the highest
of the wind speeds to affect the southern panhandle and along the
coastline as the next front moves in.

&&

.MARINE...
For the Gulf, expect fresh to strong breezes through the morning
before a southeasterly gale force low moves into the central Gulf
by Tuesday night. This is expected to increase seas to 20+ feet
through the rest of the week.

For the inner channels, expect moderate to fresh Southerly
breezes in the morning. Winds will diminish and switch northerly
in response to the gale force low in the Gulf. Overnight into
Wednesday, Northerly winds will switch Southerly. Expect gales
through Clarence Strait and gale force gusts in Southern Chatham
Strait, including near gales in Sumner Strait and Frederick
Sound.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory until 3 PM AKST this afternoon for
     AKZ318-319.
     Winter Storm Watch from Wednesday morning through Wednesday
     evening for AKZ318.
     Strong Wind late tonight for AKZ323.
     High Wind Watch from Wednesday morning through Wednesday evening
     for AKZ328-330-332.
MARINE...Gale Warning for PKZ022-036-641>644-661>664-671.
     Small Craft Advisory for PKZ012-013-033-035-651-652-672.

&&

SHORT TERM...ZTK/BC
LONG TERM....NC
AVIATION...Contino/SF
MARINE...ZTK/BC

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