Heavy Freezing Spray Warning 21, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
223 PM AKST Sun Feb 11 2024

.SYNOPSIS...

Active weather continues for much of Alaska into early next week
before a more tranquil, springtime pattern sets up mid week into
next weekend. Light snow through the interior and West Coast
tapers off later today with a lull in active weather through
midday Monday. A Winter Weather Advisory for blowing snow and low
vis remains in effect until 6pm this evening for Point Lay.

A strong storm system rides up the West Coast Monday evening
through Wednesday bringing an extended period of snow, mixed
precipitation, and wind to the Western Interior, West Coast, and
portions of the North Slope. A Special Weather Statement and a
number of Winter Storm Watches are in effect for these areas in
anticipation of the impactful conditions. South winds gusting to
35 mph are expected through Atigun Pass on Monday night, while
High Wind Watches have been posted for the Alaska Range passes
Monday afternoon through Wednesday afternoon as increasing
gradients and a strong low level jet will result in another, even
stronger high wind event through the passes. Near and even above
freezing temperatures are possible over much of the central and
eastern Interior including Fairbanks, especially over elevated
terrain Tuesday through possibly next weekend.

&&

.DISCUSSION...

Analysis and Model Discussion...

Guidance has a fairly good handle on the synoptic pattern today
with troughing remaining over the Bering with a weakening 989mb
surface low moving right over Nome this afternoon and a surface
front extending eastward across the Interior. Gradient winds
across the state have weakened considerably today as indicated by
observations within the Alaska Range passes with southerly wind
gusts falling under 30 mph. Due to less downsloping, clouds and
precipitation have been able to form along the W-E oriented
frontal boundary stretching from around Nome to Eagle. Shortwaves
along the front have resulted in bands of snow forming across the
Interior and around Fairbanks today. Steep lapse rates aloft and
deeper saturation as downsloping has ended has resulted in
convective snow shower bands reducing visibility to one mile at
times for Fairbanks and surrounding areas. This front will slowly
push north this evening with a drying trend on the backside;
however low visibility due to fog may persist.

Beginning Monday and persisting through the week, strong upper
ridging builds over Alaska with a closed 560dm high centered over
Yakutat. The ridge will bring clear skies, much above normal
temperatures, and strong inversions to the central and eastern
Interior and even north to the Arctic Coast east of Utqiagvik.
Along the West Coast, a quasi atmospheric river type pattern sets
up on the western edge of the ridge Monday evening through
Wednesday with an intense S-N 130 kt upper jet extending from
around 30N to the Arctic Coast by Tuesday. Guidance is coming
into better agreement on the track of the 985mb surface low moving
north from the AK Peninsula to Hooper Bay then to the Chukchi Sea
by Wednesday morning. In the wake of the low, a strong baroclinic
zone and S-N boundary sets up across the Western Interior
separating warmer air and SE flow from arctic air and SW flow.
This boundary will be the main focus for heavy precipitation
Monday night through Wednesday as shortwaves ride up along it.
While there are still some model differences regarding exact track
and timing of the low, high enough confidence exists in this
pattern setting up that Winter Storm Watches and SPS have been
issued for much of the Western Interior and Nulato Hills. Heavy
precipitation may even extend as far north as the western North
Slope. There may be P-type issues initially, especially in the YK
Delta initially; however guidance indicates deeper, colder air
filtering in as the low occludes and pushes northward.

Additional weather concerns will be periods of high southerly
winds through Alaska Range Passes, Tanana Valley Jet winds at
Delta Junction, and blowing snow near Eagle Summit. Guidance
indicates nearly a 15-20mb low level pressure gradient across the
Alaska range with 850-700mb flow up to 75 kts Monday evening
through Wednesday. Have issued High Wind Watches for this time
period for Alaska Range Passes due to high winds. This event looks
to be much stronger than the strong winds which occurred over the
last couple days.

Central and Eastern Interior...

Light snow will be tapering off today across the interior as a W-E
surface front pushes northward into the Brooks Range. Generally
quiet weather is expected through Tuesday with the exception of
strong southerly winds through Alaska Range Passes. As mentioned,
High Wind Watches for the Parks Highway south of Healy, Fort
Greely and Delta Junction, and the Richardson Hwy north of Trims
Camp for gusts to and possibly over 70 mph  Monday afternoon
through Wednesday afternoon. Blowing snow near Eagle Summit will
diminish by Monday morning, as will snow south of the Denali Park
entrance and south of Trims Camp. Temperatures will continue to
run well above normal, and near and even above freezing
temperatures are possible over much of the area, especially over
elevated terrain Tuesday through Friday beneath the strong ridge.

North Slope and Brooks Range...

A Winter Weather Advisory for blowing snow and low visibility in
effect until 6AM Monday from Wainwright to Point Lay. Expect the
gradient to relax and conditions to improve after the surface front
moves north of the area tomorrow. South winds gusting to 35 mph
are expected through Atigun Pass on Monday night. Otherwise,
weather will be mostly non impactful with some flurries and
isolated areas of blowing snow near the coast. Temperatures will
follow a sharp warming trend as the ridge builds over the area,
with highs reaching the teens and 20s above zero by Tuesday.

West Coast and Western Interior...

Light snow will continue across much of the area today. As
mentioned above, impactful weather will return to this region
Monday afternoon through Wednesday with heavy precipitation, wind,
and warmer temperatures. A Special Weather Statement and a number
of Winter Storm Watches are in effect for the Yukon Delta, Lower
Yukon, and Nulato Hills. Kaltag may see up to 11 inches of snow
with this system and ice accumulation of up to one tenth of an
inch is possible through Wednesday. Precipitation will likely
begin as snow before turning to freezing rain, then back to snow
in most areas. Additional watch/warning/advisory products will
likely be needed as specific details regarding low track and
timing become more clear.

Coastal Hazard Potential Days 3 and 4...

With the track of the surface low for Monday into Wednesday
trending closer to or right along the West Coast, concerns are a
little less for sea level rises. However potential is there for
minor rises on the southern coast of the Seward Peninsula and
water on top of sea ice.

Extended Forecast For Days 4 Through 7...

The building ridge over much of the state is expected to persist
into next weekend. Longer range models and ensembles continue to
indicate the ridge becoming more NW-SE oriented by late week
possibly shifting the storm track further west, bringing drier
conditions to the West Coast. Expect well above average
temperatures and dry conditions to persist over the Interior and
North Slope into the weekend. Temperatures may reach or even exceed
freezing in many locations including Fairbanks through Friday. The
only weather concern there through next weekend will be south
winds through Alaska Range Passes and Tanana Valley Jet winds at
Delta Junction. These types of blocking patterns usually last for
10-14+ days with guidance trying to break down the ridge too
soon. Therefore low confidence exists in model solutions showing
lows pushing into Southwest Alaska by the weekend.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Weather Advisory for AKZ801-802.
     Winter Storm Watch for AKZ825-826.
     Winter Storm Watch for AKZ829-830.
     High Wind Watch for AKZ837-847-849.
PK...Heavy Freezing Spray Warning for PKZ801-802-850.
     Brisk Wind Advisory for PKZ803>805-852-854.
     Brisk Wind Advisory for PKZ806.
     Brisk Wind Advisory for PKZ807.
     Brisk Wind Advisory for PKZ808.
     Brisk Wind Advisory for PKZ809-855.
     Brisk Wind Advisory for PKZ810.
     Brisk Wind Advisory for PKZ811-857.
     Gale Warning for PKZ812.
     Brisk Wind Advisory for PKZ813-856-859.
     Gale Warning for PKZ858.
&&

CM