High Wind Warning 3, NWS Juneau, AK

390 
WWAK77 PAJK 201408
NPWAJK

URGENT - WEATHER MESSAGE
National Weather Service Juneau AK
508 AM AKST Sat Jan 20 2024

AKZ318-201515-
/O.CAN.PAJK.HW.W.0003.000000T0000Z-240120T1500Z/
Municipality of Skagway-
Including the cities of Skagway and White Pass
508 AM AKST Sat Jan 20 2024

...HIGH WIND WARNING IS CANCELLED...

Strong outflow winds persist early this morning. Pressure gradient
will ease slightly through the morning before increasing again
late Saturday night. Occasional wind gusts to 55mph will continue
through the day.

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
252 PM AKST Fri Jan 19 2024

.SHORT TERM...A front approaching from the south will over run
very cold surface air as it tracks north and there will be
accumulating snow beginning saturday and expanding north through
Saturday night. Prior to then, forecast model sounding are
indicating a very good chance of freezing rain and/or drizzle over
the southern Panhandle for tonight. The night shift picked up on
this overnight and we have continued and slightly expanded on
their work. A winter weather advisory remains in effect to cover
this.

Outflow winds continued to be very strong today in the favored
windy spots of downtown Juneau and Skagway. High wind gusts in
excess of 60 mph in downtown Juneau have been frequent enough to
warrant another extension of the high wind warning there - now
out to 9 pm this evening. Elsewhere, Skagway was consistently
gusting to 50 mph until noon when high wind gusts were first
observed there. That prompted a high wind warning there - also
expected to end by 9 pm tonight. In addition to the high winds in
Skagway, very cold temperatures and strong winds at White pass
are cold enough to justify a wind chill advisory and almost cold
enough for a wind chill warning. Wind chill concerns will diminish
tomorrow as outflow winds relax a bit.

.LONG TERM...Main story for the midweek is the pattern change for the
entire panhandle this weekend. Ensemble guidance is suggesting
that outflow winds will be coming to an end and temperatures will
be on a constant rise through the weekend. This is thanks in part
to several frontal waves moving up the panhandle from a parent low
near the Alaskan Peninsula beginning Saturday. Cold air and
northerly outflow will hold off much of the precip in the central
and northern panhandle Saturday before a stronger frontal wave
moves up the panhandle Sunday. Prior to this wave, 850 mb
temperatures look to warm substantially across the southern
panhandle to 0 degrees Celsius. Therefore, much of the
precipitation falling across the southern panhandle will fall as
rain except at elevation over PoW Island. Then on Sunday, the
southerly wave will push northward, changing any remaining areas
to rain as it moves north. Then, it looks like cold air will stall
the front. Along this front from Icy Strait northward, a band of
snow will follow. Unfortunately, how much warm air will push
northward, how much cold air will be in place to prevent the front
from moving northward, how much moisture will actually be present
after pushing through the cold, dry air, and where the boundary
will stall are all questions which will effect accumulating snow
totals. At this time, ensemble guidance seems to indicate that a
80% chance of at least 0.25 inches of QPF is expected for the
Juneau area and similar percentages for the Icy Strait corridor of
at least 0.20 inches of QPF. Combine that with the relatively low
snow ratios of around 12:1 diminishing down to 8:1 means that
around 5 - 8 inches is expected. Therefore, this prompted a winter
storm watch for the Icy Strait corridor and Juneau on Sunday.
Less moisture is expected to reach up near Haines, but snow ratios
are expected to be higher. Therefore, 3 - 5 inches are also
expected for Haines. The main trend compared to yesterday is the
increase in QPF across the Icy Strait corridor, and the band
remaining somewhat stationary for the heavier precipitation. With
the heavier precip, it may lean toward precip type staying as snow
for longer through Sunday night, particularly for the Juneau
area.

What is high confidence is we will be on the warming trend into next
week with temperatures becoming above normal instead of the below
normal temperatures that the panhandle has been experiencing. Along
with the warming trend, more rain is in the forecast as an active
pattern fully takes hold. One thing to note is LREF grand ensemble
seems to indicate a possibly potent system moving in late next week.
At this time, the Anchorage area appears to take the brunt of the
impacts, however, more will become clear with time. Stay tuned for
more information.

&&

.AVIATION...CAVU most locations across SE Alaska this afternoon
into the late evening hours, with the exception of VFR transitioning
to MVFR across the southern Panhandle this evening as a weak
front moves up from the eastern GULFAK and British Columbia.
Freezing drizzle is possible late tonight into Saturday morning
for Klawock and Ketchikan where periods of IFR is also possible
after 12Z until around 20Z. The central and northern Panhandle
areas are expected to remain dry overnight into Saturday morning
where deeper dry and cold air resides. Ceilings and visibilities
start dropping from south to north through late Saturday as the
front moves north and snow becomes more widespread.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...High Wind Warning until 9 PM AKST this evening for AKZ318-325.
     Strong Wind from 9 PM AKST this evening through late tonight for
     AKZ318.
     Winter Storm Watch from Sunday afternoon through late Sunday
     night for AKZ320>322-325.
     Strong Wind from 9 PM AKST this evening through late tonight for
     AKZ325.
MARINE...Gale Warning for PKZ012-013.
     Small Craft Advisory for PKZ021-022-031-032-034-053-641>644-651-
     652-661>664-671-672.

&&

SHORT TERM...Fritsch
LONG TERM....NC
AVIATION...JG

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