Wind Chill Advisory 5, NWS Fairbanks, AK

Northern Alaska Forecast Discussion...CORRECTED
National Weather Service Fairbanks AK
130 PM AKST Tue Jan 8 2019

.DISCUSSION...

Synopsis...Some relief from the cold, but it looks like it will
come back with a vengeance for another day or two later in the
week. A decaying weather front will move across the Southern
Interior the next 24 hours or so bringing some clouds and snow
that will help warm things up a bit from Tanana south. Snowfall
will be heaviest around McGrath with up to 4 inches with lesser
amounts as the system moves east. Behind that front more cold air
pushing south over the area will push temperatures colder than we
have seen the last few days. Not much change on the Arctic Coast,
but expect some wind chill issues in the Brooks Range, and along
the south slopes as the week goes on. The West Coast will remain
cold as well, with lows falling into the 30s below for the end of
the week even along the coast as far south as Emmonak.

Models...Short term the 08/12Z surface solutions initialized well
against the local 08/18Z surface analysis. Aloft the 850 hpa
temperatures initialized 2 to 4 degrees warmer than the McGrath
12Z upper air sounding, and a 15Z sounding from Ft Greeley.
Solutions are in good agreement in the short term, and even show
agreement through about 96 hours before they start diverging on
the position of major features. They are consistent in building
the ridging back to the northwest through Monday with a shortwave
moving up the West Coast Sunday, and another, stronger wave,
Monday. Not a lot of precipitation to deal with, and solutions are
pretty agreeable, so will use a pretty even blend today with a
kick from the SREF to increase the probabilities.

Aloft...At 500 hpa...Pattern change in progress as a 502 dam low
300 nm north of Deadhorse will dig south over the next couple days
to be over Galena by Thursday afternoon at 498 dam. The low turns
and moves northeast to be over Anaktuvuk Pass by Saturday morning
at 500 dam. Ridging that extends from northwest of Wrangel Island
over St Lawrence Island and Sand Point will be pushed west as the
low digs south, and ridging over the southern interior and
Southcentral Alaska will be pushed southeast. By Thursday night a
534 dam high will be 600 nm north of Wrangel Island with ridging
extending southeast across the Arctic to Banks Island. At 850
hpa...Temperatures 2 to 4 degrees colder than what models are
putting out this morning. As a decaying from moves through the
area, temperatures in the southern interior will warm couple
degrees, but cool rapidly behind it. The -20C isotherm lies from
Eagle to Livengood to Tanana to Selawik to Cape Lisburne this and
will move not move much as the front moves through. After the
front the -20C isotherm moves south to lie along the crest of the
Alaska Range then northwest over McGrath to Shishmaref Thursday
morning. Friday morning the -20C isotherm will be south of the
forecast area with temperatures around Fairbanks near -28C.
Temperatures will start warming Saturday as the -20C isotherm
starts moving back to the north with the -10C isotherm closely
behind it.

Surface...High pressure over most of the state will continue as
it pushes in from the east from a 1036 mb high over the Yukon
Territory, and south from a 1036 mb high over the Western Arctic
and a 1033 mb high over the Arctic Plain. Leeside trough north of
the Alaska Range this morning with Tanana Valley Jet kicking up
around Delta Junction. A 1029 mb low is 200 nm north of Kaktovik
this afternoon, and a broad area of low pressure extends east over
the Bering Sea from a 978 mb low near the Kamchatka Peninsula. By
Wednesday afternoon high pressure remains over the Southern
Interior, Middle Yukon River Valley, Lower Yukon Delta, a trough
along the south slopes of the Brooks Range, high pressure over the
Arctic Plain, and weak trough over the Eastern Arctic Coast. A
decaying weather front will move across the Southern Interior
bringing some clouds and light snow to areas from McGrath to Ft
Yukon as it moves northeast across the area. By Friday morning a
1044 mb high will be 600 nm north of Kaktovik with a weak band of
low pressure extending from the Middle Yukon Valley to the Upper
Yukon Flats, and high pressure from Livengood southeast.

Arctic Coast and Brooks Range...Increasing clouds for the next
day or so with some light snow and flurries and accumulations
around 1 inch. Then Clearing skies as high pressure builds back
over the area. Winds will remain fairly light for the Arctic Coast
and Plain at less than 15 mph for most locations. Expect the
winds in the Brooks Range to pick up from the north as the
gradient tightens up across the area with troughing south of the
range. Winds in channeled areas, and around Anaktuvuk Pass will be
north to 20 to 25 mph and gusty. With the cold temperatures Wind
Chill will be around 55 below Thursday night and Friday.

West Coast and Western Interior...Snow developing in the Lower
Yukon Delta, Upper Kuskokwim Valley and along the Western Alaska
Range. Some snow possible as far north as Galena. Heaviest will be
in the Upper Kuskokwim Valley with up to 5 inches of snowfall by
Wednesday afternoon. Areas that remain clear will remain cold with
temperatures -15F to -40F for most locations and the coldest areas
will be inland. Winds generally light. Along the Brooks Range
north winds will kick up so along the range Wind Chill will be an
issue as winds gusting up to 25 mph are possible, and Wind Chill
will be around 55 below Thursday night and Friday.

Central and Eastern Interior...Band of light snow that moved
through Fairbanks will continue to the northeast, then move north
with just light accumulations. Another band will move across the
Southern Interior tonight with up to one inch of accumulation.
After it moves through skies will clear and the cold will return
with even colder temperatures expected Thursday evening through
Saturday morning. Temperatures in Fairbanks and vicinity will fall
into the 40s below, while temperatures in the Upper Yukon and
Upper Tanana Valleys will fall into the 50s below. A warm up will
begin Saturday and continue into next week. Winds will generally
be light, but north winds along the Brooks Range will produce
cold Wind Chill Wednesday evening through Friday.

&&

Extended forecast for days 4 to 7...Model solutions all agree on a
warming trend starting Saturday and continuing through Monday
before it starts cooling back down. Expect some snow west of
Tanana Sunday with one inch or so of accumulation, then a
significant snow Monday as a low moves north up the West Coast.
Current snowfall projections bring 2 to 6 inches of snow to the
West Coast Sunday night and Monday, so will need to keep a close
watch on the development of the system.

&&

Coastal Hazard Potential Days 3 and 4...None.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Wind Chill Advisory for AKZ207.

Gale Warning for PKZ210.

Brisk Wind Advisory for PKZ200-PKZ220.

&&

SDB JAN 19