High Wind in Alaska, January 14, 2020

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
542 AM AKST Tue Jan 14 2020

.SHORT TERM...The short term forecast through the middle of the
week will continue to be dominated by breezy and cold conditions.
Very cold outflow from Northwest Canada through the panhandle,
reaching even as far as the southern panhandle is seeing
overnight lows in or near single digits or colder. Some stations
around the SE haven't seen temperatures this cold in a decade or
longer. Wind chills 25 to 45 below over the northern inner
channels during the next couple of days can be expected, with
even colder wind chills in Skagway and White Pass - with White
Pass in particular seeing wind chills dipping past 55 below at
various times all the way through Thursday morning, and a Wind
Chill Warning was issued to reflect this. Generally speaking
temperatures will be fairly similar to what they have been these
past few days, but adjusted minimum temperatures slightly lower,
and maximum temperatures slightly higher, to better reflect the
limited diurnal heating/cooling available given the relative lack
of cloud cover and low sun angle. slightly cooler overnight lows
compared to this morning for Tuesday and the same for Wednesday.
Temperatures in some areas may fluctuate at times as mixing helps occasionally
bring down air from more elevated heights down to the surface.

An additional shot of wind is looking increasingly likely for much
of SE Alaska on Wednesday night and Thursday, which could see
even colder temperatures and wind chills take hold in the
panhandle, and some areas may need strong wind headlines,
particularly in the northern panhandle. Small craft winds for
portions of the inner channels, with gales in Lynn Canal Tuesday
night, along with some enhanced and more fully developed seas in
the longer straighter channels. In addition, freezing spray will
be the norm for much of the inner channels during the forecast
period. Forecast confidence is good through middle of the week.

.LONG TERM.../Thursday through Tuesday as of 10 pm Monday/ Signs
of change are still in the cards for the long range period as
precipitation and less outflow returns for the weekend. Overall
expected upper level pattern has not changed much since yesterday
with a ridge over Western Alaska transitioning to a broad trough
by early next week. About the only change from yesterday is that
the merging of the upper lows over the AK Peninsula late week has
been pushed back by about half a day.

For the panhandle, Strong outflow and cold temperatures expected
to continue into Fri. Freezing spray remains an issue for many
marine areas and low wind chills are still expected in windy
areas. Little change in the forecast here.

Long range guidance has gotten better for the low trying to move
north into the eastern gulf Fri. However compared to yesterday the
low is stronger, and the track is farther out to sea. Also due to
this, the arrival of significant precip into the southern
panhandle is slower by about 6 to 12 hours. Now instead of the
precip arriving Fri evening, it will more likely be late Fri night
before the precip moves in to the south, and will not impact the
north until Sat at least. The deep cold air will still be present
so significant snowfall is still possible for the southern
panhandle, just at a later time then previously forecast. There is
the possibility that later model runs will push this timing even
further back as we get closer to the event so limited the
possibility of precip to likely as a result. Favored ECMWF and
WPC for updates here.

Southerly flow continue behind the first low that will bring
another system into the southern panhandle for early next week.
However model agreement is poor with the only certainty being that
there will still be precipitation in the area with more southerly
flow gradually warming temperatures into early next week.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...Wind Chill Advisory from 11 PM this evening to 10 AM AKST
     Wednesday for AKZ019.
     Wind Chill Advisory from 9 PM Wednesday to 9 AM AKST Thursday
     for AKZ019.
     Wind Chill Warning until 10 AM AKST Thursday for AKZ018.
     Strong Wind through late tonight for AKZ018.
MARINE...Heavy Freezing Spray Warning for PKZ031.
     Heavy Freezing Spray Warning for PKZ031.
     Heavy Freezing Spray Warning for PKZ034.
     Heavy Freezing Spray Warning for PKZ012.
     Heavy Freezing Spray Warning for PKZ013-032.
     Heavy Freezing Spray Warning for PKZ035.
     Heavy Freezing Spray Warning for PKZ035.
     Gale Warning for PKZ012-013.
     Small Craft Advisory for PKZ021-022-031>034-041>043-051-052.

&&

GFS/EAL

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