Blizzard Warning 12, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
216 PM AKST Thu Feb 15 2024

.SYNOPSIS...

Active weather continues along the West Coast of Alaska while
drier and warmer conditions persist for the Interior. A variety of
Winter Storm Warnings and Winter Weather Advisories remain in
effect from Southwest Alaska northward into the Seward Peninsula
as the storm track and associated frontal boundary has been
stalled out over this region for several days. Additional rounds
of heavy and blowing snow, and mixed precipitation are expected
for the far Western Interior and West Coast through early
Saturday morning with the axis of heaviest precipitation slowly
pushing westward in time. Northerly winds increase through the
Bering Strait today and tomorrow prompting the issuance of Winter
Weather Advisories for blowing snow for the Western Seward
Peninsula, St. Lawrence Island, and along the NW Coast. Further
inland, southerly flow and downsloping off the Alaska range has
past its peak intensity with gusts in the 40 to 60 mph range for
the passes today and tomorrow. High Wind Warning has been canceled
for Parks Hwy as gusts are expected to remain under 60 mph
through Friday. Wind Advisories remain in effect for Delta
Junction and the Richardson Hwy where sporadic gusts of 50 to 60
mph will persist into tomorrow. Dry conditions with well above
average temperatures near to above freezing will continue across
the Interior as high pressure and ridging aloft remain the
dominant weather influence into the weekend.

&&

.DISCUSSION...

Analysis and Model Discussion...

Guidance is in fairly good agreement with the synoptic weather
pattern through the weekend, then discrepancies increase next week
as low pressure systems enter the Bering and start breaking down
the blocking ridge over the state. Aloft today, strong ridging
centered over Yakutat and extending over the majority of the state
will become more NW-SE oriented into the weekend pushing the main
storm track along the West Coast further westward. High pressure
persists over NW Canada and Eastern Alaska keeping the interior
and North Slope fairly dry. Across the Alaska range, cross barrier
flow and the pressure gradient will slowly diminish Friday;
allowing winds through the passes to come down below advisory
criteria. Downsloping and anomalously warm low 850mb temperatures
will still result in high temperatures well above normal for this
time of year across the state in the 20s and 30s through the
weekend.

The main focus for active weather is across the West Coast where
a frontal boundary sits from Southwest Alaska northward to the
western Brooks range. Waves of energy riding along the boundary
in addition to strong southerly flow through the column, pumping
in ample pacific moisture northward, has resulted in heavy
precipitation across Western Alaska for the last 48 hours.
Guidance is all in agreement with this boundary slowly pushing
westward this evening and tomorrow as the ridge builds further
west. Waves of low pressure rotating around a NW-SE elongated
parent low just south of the AK Peninsula will bring additional
round of precipitation to SW Alaska and the Seward Peninsula this
evening into Saturday. Southwest Alaska will be placed in an area
for enhanced lift within the right entrance region of a jet streak
pushing northward around the ridge. A strong southeasterly low
level jet increases to 50-60 kts tonight over SW Alaska as a wave
associated with the triple point of the parent low moves northwest
along into Bristol Bay and along the coast. This will pump in
additional moisture over the quasi-stationary boundary keeping
heavy precipitation around through this region. Southeasterly warm
air advection on the east side of the boundary will significantly
warm the lower levels leading to a transition to freezing rain
and plain rain from east to west at times Friday afternoon into
Saturday morning for SW Alaska. Areas right along the coast from
Hooper Bay to St Michael's to Golovin and points west will likely
remain snow longer, while the threat for freezing rain and plain
rain is highest further inland east of the boundary. Total snow
accumulations up to 5 to 8 inches are expected for the YK Delta,
with higher accumulations for the Nulato Hills. Depending on how
strong warm air advection is Friday, additional snow totals may
be less further inland where rain and freezing rain mix in at
times. With the best axis of moisture advection remaining in
Southwest Alaska, lower snow amounts are expected for the Seward
Peninsula than areas further south.

Central and Eastern Interior...

As mentioned above, more tranquil and warmer conditions persist
for the interior under the influence of upper level ridging
holding in place. Temperatures will be in the 30s and 40s today
for areas surrounding the Alaska Range, dropping into the 20s and
30s for Friday into the weekend. Large temperature gradients will
still exist between valleys and areas at higher elevation with
low temperatures falling near zero in valleys and remaining much
warmer aloft.

Winds along the Alaska Range are already diminishing today and
this trend will continue into tomorrow. Gusts today have maxed out
in the 50-60 mph range with the strongest gusts near Delta
Junction as the Tanana Valley Jet has more influence over their
winds as southerly downsloping winds through Isabell pass
diminish. Breezy conditions and downsloping winds will likely
continue this weekend, but speeds should remain below advisory or
warning criteria.

North Slope and Brooks Range...

Low pressure in the high arctic with higher pressure building
into the Chukchi sea will result in persistent northerly flow
along the North Slope. A tightening pressure gradient by Friday
afternoon will produce elevated winds along the northwest coast,
persisting into the weekend. There may be blowing snow issues from
Point Lay to Point Hope where the strongest NE winds of up to
30-40+ mph are expected Saturday into early next week.
Additionally, gusty south/southwesterly winds along the Brooks
Range will continue tonight, diminishing through Friday morning.
Temperatures will remain around -10 to +5 for the North Slope.

West Coast and Western Interior...

Active weather continues through the first part of the weekend for
the west coast as mentioned above. Heavy precipitation will
persist along a N-S boundary across Western Alaska, shifting
westward in time. Winter Storm Warnings remain in effect for the
YK delta through Saturday morning where an additional 5 to 10
inches of snow could fall, mixing with rain and freezing rain at
times Friday for inland areas of Southwest Alaska. As the boundary
pushes west, warm air advection from the southeast may lead to
temperatures rising n to ear or above freezing this weekend,
especially in downsloped favored areas. Expect a drying trend into
Sunday for much of Western Alaska, with the exception of areas
right along the coast that could be impacted by incoming fronts in
the Bering.

Blowing snow and low visibility may become an issue for the
Western Seward Peninsula and through the Bering Strait Friday
through Sunday as northerly winds increase on top of fresh
snowfall. Winter Weather Advisories are already in place for low
visibility due to blowing snow.

Extended Forecast For Days 4 Through 7...

Upper ridging continues across much of the state into next week;
however guidance shows the ridge slowly weakening in time as
multiple areas of low pressure push fronts into the West Coast.
Above average temperatures will persist for much of the state
next week despite a slow downward trend in temperatures as the
ridge weakens. The most active weather will remain along the West
Coast and Southwest Alaska as numerous frontal boundary push in
from the west. The ridge across the state should prevent
precipitation from making much progress inland, keeping the
majority of the interior dry.

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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Weather Advisory for AKZ801.
     Winter Weather Advisory for AKZ820-821-827.
     Winter Storm Warning for AKZ822-824.
     Winter Storm Warning for AKZ825.
     Winter Storm Warning for AKZ826-830.
     Wind Advisory for AKZ834.
     Wind Advisory for AKZ837-849.
PK...Brisk Wind Advisory for PKZ801-850.
     Gale Warning for PKZ801-802.
     Brisk Wind Advisory for PKZ803.
     Brisk Wind Advisory for PKZ804-810-851-853.
     Brisk Wind Advisory for PKZ805.
     Gale Warning for PKZ806-807-854.
     Brisk Wind Advisory for PKZ811-857.
     Brisk Wind Advisory for PKZ816-817-852.
     Gale Warning for PKZ850.
     Gale Warning for PKZ856.
&&

CM