Wind Chill Warning 6, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
532 AM AKST Wed Dec 25 2019

.SYNOPSIS...
A cold air mass will push into the Interior tonight and will
persist into the weekend. This will bring temperatures of 30 to
50 below zero at times.

&&

.DISCUSSION...
Looking the the 00Z model suite, he models are coming into better
agreement out through the weekend, although there are still some
minor differences. We will lean on the 00Z GFS, especially for
the placement of the cloud cover for the Interior on Thursday and
Friday.

Aloft at 500 mb, a trough stretches from a 474 dam low in the
Beaufort Sea over Deadhorse and southwest to McGrath. The trough
axis will very slowly push the east through Friday. Very cold air
aloft will push southward into the Interior with 850 mb
temperatures of -25 to -35 degrees Celsius across much of the
forecast area into the weekend. On Saturday the trough pushes to
the southwest and a clods low forms over Bristol Bay. When this
happens, southerly flow aloft will develop over the Alaska Range.
the southerly flow will help to advect warmer air over the
Interior. By Monday, both the GFS and the ECMWF have H850
temperatures in the single digits below zero Celsius. The GFS and
the ECMWF both have the southerly flow aloft persisting into
Tuesday. This is actually a big change since yesterday in both
models. Yesterday, both the ECMWF and the GFS should the southerly
flow only lasting for about 24 hours and a very cold trough
returning over the area for the first part of the week. The models
are hinting at a colder pattern over the Interior late next week.

Central and Eastern Interior: A shortwave moving to the northeast
will bring snow this morning, generally along a line from
Fairbanks to Circle. The snow will generally taper off by late
morning. Colder air aloft will push south over the Interior
tonight. Areas to the northwest of a line from Venetie to Minto to
Nikolai will be clear and will see temperatures from 35 to 45
degrees below zero or colder tonight into Sunday. Ice fog is
likely to develop near villages in this area. Areas to the
southeast of this line, including Fairbanks, will see cloud
cover, chances for snow and temperatures in the teens to lower 20s
below. The chances for snow in this area increase some on
Thursday as a shortwave moves northeast through the area. Up to 2
inches of snow is possible southeast of a line from Circle to
Nenana tonight and Thursday. As the longwave trough pushes to the
east Thursday night, clouds in the eastern Interior will begin to
clear out from west to east. As skies in the southeastern Interior
clear, temperatures will drop to the 35 to 45 below range.
Fairbanks will likely clear out early Friday morning. Temperatures
will fall in Fairbanks during the day on Friday and will drop
below 40 degrees below zero by Friday evening at valley level. In
the hills, temperatures will drop to around 25 below once the
clouds clear out. We went with the GFS timing of the clouds
clearing out. The NAM has the clouds clearing over Fairbanks about
12 hours earlier, so we will have to continue to monitor trends.
Ice fog is possible in Fairbanks Friday and Friday night as the
temperature drops. Southerly flow will develop aloft over the
Interior on Sunday. Cloud cover will push over the Interior from
south to north on Saturday helping to moderate temperatures. The
southerly flow and cloud cover look to persist into the first part
of next week. The models are hinting as another very cold period
for the second half of next week. With the very cold temperatures
in place combined with a little bit of wind, wind chill values
will be an issue today. Wind Chill Advisories are currently out
for zones 218, 219, 220 and 221.

West Coast and Western Interior: Northerly winds of 15 to 25 mph
continue today through the Bering Strait and over St. Lawrence.
As high pressure over the Chukotsk Peninsula strengthens on
Thursday night the winds will increase to around 35 mph. With the
persistent northerly winds snow and blowing snow is expected over
St. Lawrence Island and the Bering Strait Coast with 1 to 2
inches of snow a day through Saturday. Elsewhere cold temperatures
will be the big story. Temperatures in the western Interior will
fall as colder air aloft moves in. By tonight, expect
temperatures of 35 to 50 degrees below zero, with the cold
temperatures expected to persist into the weekend. Current models
show some moderation in temperatures early next week. With the
very cold temperatures in place combined with a little bit of
wind, wind chill values will be an issue. Wind Chill Advisories
are currently out for zones 207, 208, 217, 210 and 212. Ice fog
will also be an issue at times near villages through the weekend.

North Slope and Brooks Range: Very cold temperatures are in place
this morning across the north Slope. The Prudhoe Bay area is
currently colder than minus 40. Farther west, Utqiagvik is close
to minus 30 and Wainwright is around minus 20. Infrared satellite
suggests temperatures temperatures close to minus 50 over much of
the Arctic Plain. Winds will pick up some today over the Chukchi
Sea Coast and wind chill values will become an issue in zone 201.
The ongoing Wind Chill Advisory looks to be in good shape.
Temperatures look to be a little warmer tonight, although still
in the 20 to 40 degree below zero range. Winds along the Beaufort
Sea Coast pick up on Thursday. With the cold temperatures in place
wind chill values will likely approach advisory levels Thursday
night into Friday. Gusty northerly winds in the Brooks Range will
increase on Thursday keeping wind chill values at advisory levels
along the south side of the range into Friday.

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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Wind Chill Advisory for AKZ201-AKZ206-AKZ207-AKZ208-AKZ210-
AKZ212-AKZ217-AKZ218-AKZ219-AKZ220-AKZ221.

Heavy Freezing Spray Warning for PKZ210.

Small Craft Advisory for PKZ210.

Brisk Wind Advisory for PKZ220.
&&

DEC 19