Winter Storm in Alaska, January 5 to 6, 2025

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
245 PM AKST Sat Jan 4 2025

.SHORT TERM...Snow showers continue in Yakutat as we start to see
the warm front reach the panhandle with precipitation in the
south. This warm front will continue across the entire panhandle
creating widespread precipitation by tonight. Snow will occur over
the northern and inner areas, with rain occurring along the
central coast. High snow ratios have kept the snow character more
on the dry side for many inner areas. Slightly wetter snow has
fallen along the coast. These ratios will decrease as temperatures
rise, and snow becomes more wet.

Winds will flip from northerly to southerly with this front helping
to bring in moisture and warmer air. Warm air will then start to
make its way along the the panhandle moving from the south to north.
Currently, the timing of warming to above freezing temperatures is
late tonight into tomorrow morning for the southern panhandle,
tomorrow morning for the central panhandle and Yakutat, and tomorrow
evening for areas around Icy Strait and Stevens Passage. The
transition from snow to rain my vary depending on how quickly the
warm air moves north.

.LONG TERM...A big pattern change is upon us as multiple systems are
set to push through the region from the south bringing
precipitation, wind, and warming temperatures. Little to no changes
were made to the inherited long range forecast.

On Monday, the upper level jet will see a surge of winds and
moisture, developing into an Atmospheric River type of stationary
front. The moisture plume will initially be directed at the central
gulf coast (Yakutat) then waver eastward over the panhandle for
Monday night into Tuesday. The warm air directed from the tropics
will cause snow levels to rise further as well, though high
elevation highways, particularly the Klondike, will likely see snow
stick around a bit longer after towns at sea level are expected to
have switched over to rain by Monday morning. Rainfall amounts
Monday through Tuesday look to be 3-4 inches around Yakutat and 1-3
inches elsewhere.

Still on track for conditions to deteriorate as our first storm
force low positions itself south of Kodiak Monday, driving a broad
fetch of severe gale to storm force winds across the majority of the
gulf. Wave models have continued to under perform this threat,
slowly shifting significant heights higher over the previous
week’s model runs. Expecting at least 28 to 32ft southerly fresh
seas peaking Monday, with a maximum along Cape Edgecumbe west
towards Cape Suckling. With that said, a stout jet of 75 to 85
knots near 5000ft has the potential to mix down to the surface,
driving even higher seas than model guidance is suggesting. If
this were to occur heights closer to 35ft are likely. Either way,
impressive total wave energy associated with Monday’s storm.

Models remain in fairly good agreement on a distinct 12-18 hour
break Tuesday night into Wednesday before the next surge of moisture
and wind arrives for Thursday. This next system will further enhance
warming across the panhandle and usher in rising snow levels leading
to increased snowmelt runoff. A hydrologic outlook has been
issued to discuss the potential impacts from these two potent
heavy precipitation events over the coming week. For more
information, see the Hydrology section below.

&&

.AVIATION...Mostly IFR expected north and central airports tonight
with MVFR to the south, but in the south we will be trending down
to IFR as southerly flow sets up and the next period of
precipitation starts to take shape. Mostly a rain/snow mix for
Yakutat, Klawock and Ketchikan overnight with snow for the
remainder of the central and northern airports where the cold air
still resides. We will need to add a mention of low level wind
shear at Yakutat in the lowest 3Kft initially.

&&

.MARINE...Winds and seas along the northern inner channels and
the northern gulf continue to gale, but will diminish tonight to
fresh breezes as the gradient continues to decrease. Otherwise, a
storm force low moves into the western gulf late Sunday into
Monday. Winds along the central and northern gulf will quickly
increase to southeasterly gales. As the low gets closer, these
gales will move toward the coast with storm force winds in the
gulf and along the far northern coast. With consistent
southeasterly winds, seas can build to 30 to 35 ft later Monday
into Tuesday.

&&

.HYDROLOGY...Pair of atmospheric rivers inbound early part of the
week based on increasing confidence of the mid and long range
models. First feature for Tuesday has a small chance of flooding
issues. It does however prime the region, and start the snowmelt
process. The second feature will take advantage of the prep, and
increased snow levels and rain to add more snow melt into the
rivers and streams.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Storm Warning until 6 AM AKST Sunday for AKZ317.
     Extreme Cold Warning until 6 AM AKST Sunday for AKZ318.
     Winter Storm Warning from 6 AM Sunday to noon AKST Monday for
     AKZ318-319.
     Winter Weather Advisory from 3 AM Sunday to midnight AKST Sunday
     night for AKZ320-325.
MARINE...Gale Warning for PKZ012-013-021-022-031-032-643-644-652-664-671-
     672.
     Small Craft Advisory for PKZ011-033-034-053-641-642-651-661>663.

&&

SHORT TERM...EAB
LONG TERM....STJ
AVIATION...JG
MARINE...EAB
HYDROLOGY...Bezenek

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