Gale Warning 155, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
342 AM AKST Tue Nov 12 2019

.DISCUSSION...

Synopsis...Another round of winter on the way for Northern Alaska as
temperatures will be falling and a front moving northwest into
the Interior will be bring significant snow to portions of the
the Central and Eastern Interior late Wednesday and Thursday.
Winds to be increasing over the forecast area south of the Brooks
Range as a strong high pressure system north of Alaska pushes
south into Northern Alaska. Travel over the highway summits may be
impacted as blowing and drifting snow as well as low wind chill
values develop.

Models...The 12/00z models suite initialized well against the 00z
surface analysis and verified well against the 06z surface
analysis. The models continue to display a large spread on the
snowfall amounts especially over the Middle Tanana Valley but
remain fairly consistent on snowfall amounts over the Forty Mile
Country and the Eastern Alaska Range as well as the higher terrain
north of and east of Fairbanks on the Wednesday and Thursday
storm. Model spread increases rapidly on the track and strength of
synoptic scale features by the end of the week.

Aloft...At 500 hpa a 498 HPA upper level low pressure center over
Banks Island with a deep trough extending southwest to the eastern
Brooks Range will continue to deep end push south and west over
Northeastern Alaska Today and Tonight and over the Central and
Eastern Interior Wednesday. The trough will continue to deepen
into a secondary upper level low pressure system over the Western
Interior Wednesday night and Thursday. This upper level low
pressure system will eventually merge with an upper level low
moving north out of the Western Gulf of Alaska into Bristol Bay
Thursday night and Friday. Much colder temperatures will accompany
the strong upper level trough and low pressure system as it moves
southwest over Northern Alaska through Friday. At 850 mb
temperatures at Fairbanks will drop from around 4 below this
morning to around 14 below on Wednesday morning and will remain
around 15 below through Friday morning. Colder temperatures will
be realized at the surface but will be modified with snow, wind
and clouds.

On the surface...A tight gradient develops between a 1040 mb high
pressure system just northwest of Alaska and a deep low pressure
system that moves into the north Gulf of Alaska late Wednesday and
Thursday. The tight gradient combined with strong cold air
advection will likely produce strong and gusty east to northeast
winds at the surface over much of Northern Alaska, especially over
the higher terrain and highway summits north of Fairbanks. Gusty
winds are also likely to develop near Delta Junction as another
Tanana Valley Jet develops Wednesday and into Thursday. Expect
considerable blowing and drifting snow to develop over treeline in
the higher terrain north of Fairbanks Wednesday night and
Thursday. Gusty north winds are expected to develop through the
Brooks Range passes as the upper level high pressure system build
south over the North Slope Wednesday night and Thursday. The much
colder temperatures combined with strong winds will produce low
wind chill values especially over the highway summits north of
Fairbanks.

Arctic Coast and Brooks Range...Weather front remains stalled over
the Eastern Arctic Coast, but continues to weaken. Persistent
onshore flow and still open water along most of the coast will do
little to dissipate the low stratus, fog and flurries over much of
the North Slope, however some breaks are expected to develop as
the high pressure to the north continues to build south over the
North Slope. Winds will continue to swing around from northwest
to northeast and will increase to the 15 to 25 mph range with
areas of higher gusts on the Eastern North Slope and through the
Brooks Range Passes.

West Coast and Western Interior...Decreasing clouds today as
offshore and dry easterly flow develops over much of the West
Coast and Western Interior. Winds will remain northeast to east
as high pressure pushes south and low pressure remains to the
south of the area. Some increasing chances of snow midweek as cold
air starts moving southwest into the area.

Central and Eastern Interior...An active weather pattern for the
Central and Eastern Interior through the end of the week. Temperatures
will cool as cold air filters in from the northeast Tuesday night
and Wednesday. Winds generally light will be increase across the
area Tuesday evening and will ramp up over the hills north of
Fairbanks Wednesday evening with northeast winds 10 to 20 mph with
gusts to 30 mph expected. Wind gusts to 40 mph will be possible
above treeline north of Fairbanks with significant blowing snow
expected Wednesday night and Thursday over the Dalton, Elliot and
Steese Highway Summits. Temperatures will fall starting Wednesday
night as some very cold air pushes southwest into the Upper Yukon
Flats and the Fortymile Country. A wave of moisture will spin into
the Interior late Wednesday bringing a multi day overrunning snow
event. Heavy snowfall is expected in areas that are favored with
northeast Upslope flow such as the Upper Tanana Valley, the
Eastern Alaska Range and Fortymile Country. Lighter snowfall is
expected over most of the Central and Eastern Interior Thursday
and Friday. Computer models continue to struggle with snowfall
amounts and where the heaviest snowfall will occur the last couple
of days however there remains the potential for significant
snowfall and travel impacts over the Central and Eastern interior
late Wednesday into Friday. Continue to monitor and evaluate the
situation.

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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory for PKZ200-PKZ210-PKZ220.

Gale Warning for PKZ200-PKZ225-PKZ230.

Heavy Freezing Spray Warning for PKZ240.

Brisk Wind Advisory for PKZ215.
&&

CCC NOV 19