000
FXAK69 PAFG 121152
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
352 AM AKDT Mon Apr 12 2021

.SYNOPSIS...
The winter storm along the West Coast continues but is beginning
to slowly weaken as it moves north east. Snow has spread all the
way to the Upper Koyukuk Valley and Kobuk Valley, and will
continuenorth and east through the day today. Over the Eastern
Interior and near the AK Range is a different story as hurricane
force chinook winds from the south have warmed temps up 40-50
degrees F from the previous two days. Much of the Eastern Interior
will remain on the warmer side of things for the next several
days.

&&

.DISCUSSION...

Upper Levels and Analysis...
A sprawling 507 dam Bering Sea low is centered just west of
Nunivak Island with a strong and moisture laden occluded front
moving inland along the West Coast and across the Western
Interior. This feature is responsible for the ongoing winter
storm out west. The surface low has weakened to gale force, and is
stacked under the upper low and is approximately 984 mb. Over the
Interior is a strengthening shortwave ridge with strong chinook
southerly flow across the AK Range. This chinook pattern has
warmed temps up dramatically over the Eastern Interior where temps
overnight remain above freezing over windy areas associated with
the Tanana Valley Jet. Hurricane force gusts are also pushing
through the AK Range gaps, mainly across Isabel Pass.

Central and Eastern Interior...
East winds associated with the Tanana Valley Jet are blasting
through Delta Junction west and north to Nenana and even Eielson
AFB. Some areas are still above freezing as these winds are
keeping the air mass well mixed, along with the extensive high
clouds. Gap winds through the AK Range remain in the near
hurricane force gust range, with periods of blowing and drifting
snow being reported earlier on the southern ends of the passes.
The strongest chinook winds weaken today, but they will remain
gusty through Tuesday. Expect the warmest temps in a very long
time as most locations will actually push above average, with some
highs nearing 50 in some areas including Fairbanks the next couple
days.

A strong low moving into the Gulf Tue night will move north of the
AK Range Wednesday, bringing a shot of rain/snow as the front
lifts north, but this will be very brief given the downslope
shadow and will favor areas north and west of the White
Mountains. Another round of strong AK Range gap winds will
develop, and Wednesday will be another warm day by the late
afternoon across most of the Eastern Interior with rain/snow
chances over the Central Interior to the Yukon Flats/Upper
Koyukuk.

West Coast and Western Interior...
The storm continues with areas of significant blowing and drifting
snow along the Coast and across the Interior as the front lifts
north. The low itself is weakening, however, and the front is
stretching out and moisture is decreasing as it tracks north of
the Brooks Range. Expect a gradual end to blizzard conditions and
heavy snow today, however, with the continued southerly flow,
expect continued heavy snow showers to impact favored coastal
areas and upslope areas such as the northern Norton Sound coast,
the Seward Peninsula Mtns, and the Baird/Western Brooks Range
Mountains. This will continue through Tuesday with more
accumulating snow before tapering Tuesday night.

The Coast will finally dry out and the Interior, too, until a
front approaches the Interior on Wednesday from the south, but the
track of this feature is up in the air. With that said, moisture
will be paltry with this front and any accumulations will be on
the lighter side.

North Slope and Brooks Range...
A strong occluded front lifting north across the W Brooks today
will bring snow threats to that area and the W Arctic coast.
Along with a tightening east gradient, snow and blowing snow will
result in localized areas of significant reduced visibility, so a
winter weather advisory remains in effect. Otherwise, the
remainder of the Slope will see increased east winds and warming
temps. Over the Eastern Brooks Range and Atigun, expect blowing
and drifting snow as winds increase into the 35 mph range from
the south before tapering off this evening. Another front moving
from the south will bring a more substantial chance for
accumulating snow for the Eastern Brooks and possible Arctic coast
Wed evening and Thu.

Extended Forecast Days 4-7...
Clarity continues to increase for the extended period forecast
beginning Thursday as the persistent south flow and broad
troughing over the state weakens and the upper level flow becomes
more zonal and favoring an arctic flow aloft. This will favor a
pattern of dry and warmer over the Interior and West Coast with a
number of fronts crossing the North Slope. This could be an active
pattern for that area, but elsewhere finally looks to see a
reprieve from active weather with temps resembling more like
spring than mid winter.


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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Wind Advisory for AKZ223-AKZ225-AKZ226.

Winter Storm Warning for AKZ211-AKZ216-AKZ217.

Blizzard Warning for AKZ213.

Winter Weather Advisory for AKZ201-AKZ206-AKZ207-AKZ208-AKZ209-
AKZ210-AKZ218-AKZ219.

Gale Warning for PKZ210.

Brisk Wind Advisory for PKZ200-PKZ215-PKZ220-PKZ225-PKZ230-
PKZ235-PKZ240-PKZ245.

&&

$$

AHSENMACHER APR 21