Area Forecast Discussion
Issued by NWS Fairbanks, AK

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432
FXAK69 PAFG 271345
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
445 AM AKST Thu Feb 27 2020

.Synopsis...Busy but benign weather pattern will persist through
Friday. Locally in the Arctic Wind Chill to 75 below this morning
and Friday morning, but winds generally less than 10 mph. Cold
temperatures will hold on across the forecast area for a couple
more days before they warm a bit.

&&

.DISCUSSION...

Models...The 27/00Z solutions show good run to run continuity,
and they are in reasonably good agreement through around 90 hours.
Big differences start showing up in the handling of a low
swinging into the Western Arctic Sunday night. Solutions continue
to be conflicted in the extended periods, so will lean on the GFS
since it has been performing better over our forecast area. The
Surface solutions initialized well against the 27/06Z surface
analysis. Will be using an equal blend of the solutions today
since there is not much precipitation in the forecast area. Well
transition to a mostly GFS/NAM blend Saturday night as those
solutions are handling the precipitation shadowing better.
Solutions seem to have finally caught up with the temperatures for
the moment, but will still need to make some minor adjustments
for local effects.

Aloft...At 500 hpa...Ridging over British Columbia and the
Southern Yukon Territory extends northwest over the Copper River
Basin to a 530 dam high west of the Gulf of Anadyr this morning.
The ridging continues to stretch out and weaken. Broad low heights
remain over the Arctic with a 482 dam low 700 nm north
Demarcation Point. The low that moved over the Northern Gulf of
Alaska last evening is over Cordova at 521 dam and will merge with
the troughing to the north later this morning. A 521 dam low that
was over Bristol Bay has moved over Kodiak Island this morning
with troughing extending west over the Southern Bering Sea. A
trough associated with the low in the Arctic lies from the low
south over Banks Island, then southwest over MacKenzie Bay to
Umiat, then Point Lay. The trough will weaken rapidly later this
morning and move east. A second trough will dig south and by this
evening will lie from Kaktovik to Fairbanks to Cook Inlet. The
trough will move east of the AlCan Border late Friday morning as
weak ridging builds north over the southwest mainland. The ridging
will continue to slide east as it flattens out. A strong
shortwave will move over the Western Arctic by Saturday morning,
and will move over the Northwest Arctic Coast by Saturday evening
as the trough slowly swings across the Arctic. A weak trough will
move over the southwest mainland late Saturday morning and move
east across the top of the ridge through the day Saturday. At 850
hpa...The -20C isotherm lies from The AlCan Border Crossing to
Cape Lisburne, and the -10C isotherm lies from McCarthy to McGrath
to St Lawrence Island this morning. By Friday morning the -20C
isotherm will push southwest a bit to lie from the AlCan Border
Crossing to Fairbanks to Kotzebue and northwest, while the -10C
isotherm will be south of the forecast area. Saturday the -20C
isotherm will move north to lie from Eagle to Bettles to Point
Hope, and the -10C isotherm will slide back north to be over the
Lower Yukon Delta. Temperatures will continue to warm slowly
Sunday.

Surface...A 1024 mb high is over the Northern Yukon Territory
with high pressure extending northwest over the Arctic Coast to
Wainwright, then southwest to a 1020 mb high over the Chukotsk
Peninsula. Broad low pressure persists over the Arctic with a 994
mb low 300 nm northeast of the New Siberian Islands, and a 1006
mb low 300 nm north of Banks Island. A weather front will move to
the Northwest Coast Friday morning and move east across the
Arctic through Sunday. The high pressure over the Arctic will be
pushed south over the Brooks Range by the weather front. Saturday
morning a 967 mb low moves to the Central Bering Sea and a
weather front moves to south of St Lawrence Island and the Lower
Yukon Delta. Sunday the front will move north but remain south of
the Bering Strait as the low moves to the Pribilof Islands at 979
mb. Friday morning a 1026 mb high will develop over the Upper
Yukon Flats. To the south a 1006 mb low in the Northern Gulf of
Alaska will be dissipating. A broad low will move to the Dateline
with a 969 mb center 150 nm north of the Aleutians and a weather
front pushing northeast to around 60N. By Sunday morning the low
will be nearing the Pribilofs, while the front will push northeast
to lie from St Lawrence Island to the Upper Yukon Flats.

Arctic Coast and Brooks Range...Mostly clear and cold. Winds
variable at 5 to 10 mph. Wind chill to 75 below today.
Temperatures are bottoming out this morning with lows in the 40s
below. Expect highs 15 to 30 below today. Temperatures will be
warming and low will be in the 15 below to 30 below range Friday.

West Coast and Western Interior...Mostly clear. Winds northeast
to east to 15 mph. Locally wind chill to 45 below this morning and
again tonight. Temperatures coldest inland with lows in the 20
below to 35 below range this morning and Friday morning.
Temperatures will be warming as the front pushes north into the
area Saturday.

Central and Eastern Interior...Some clouds and snow, or flurries,
in the Southeast Interior again today, but do not expect any
significant accumulation. Elsewhere, Mostly clear. Temperatures
will remain on the cool side with lows in the 25 below to 40 below
range for most of the area today and Saturday. Temperatures
warming a bit by Sunday, then much warmer on Monday. Winds
generally light and variable. Gusty southeast winds to 45 mph
developing Saturday near Delta Junction as the Tanana Valley Jet
sets up.

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

Extended forecast for days 4 to 7...Once again model solutions
are in good general agreement through the weekend, but becoming
quite conflicted beyond Monday. Will continue to lean on the GFS
solutions since it has performed better over the past few weeks.
As the low pressure system in the Bering Sea decays and moves
east, high pressure will push in behind the front bringing
another round of cold to the forecast area next week.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

None.

&&

$$

SDB FEB 20



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