Gale Warning 86, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
431 AM AKDT Mon Oct 15 2018

.DISCUSSION...
A more active and wintry weather pattern is expected to develop
over the eastern half of Northern Alaska with multiple wind and
winter related hazards expected. With this forecast package, will
be issuing multiple winter related hazards for freezing rain,
snow, and blowing snow as well as upgrading the wind advisory in
the Alaska Range to a High Wind Warning. Elsewhere across Western
Alaska, unsettled and windy conditions are expected over the next
couple of days. The latest 15/00Z model suite is in good agreement
with the overall synoptic pattern, but differ slightly with the
probability and placement of precipitation across Interior Alaska.
In regards to precipitation amounts and timing, have leaned
heavily on the NAM solutions as they continue to resolve the
chinook/downslope pattern and keep the precipitation out of the
southern Interior.

Aloft, at 500 mb, a 518 dam low currently positioned 150 miles
southwest of Cold Bay will move north into the southern Bering Sea
and Bristol Bay region by this evening and then will remain
quasi-stationary and weaken over the Bristol Bay region through
Wednesday. Upper level ridging extending northwest over Interior
Alaska from a 584 dam ridge center over the eastern Pacific will
slide gradually east into western Canada over the next 24 to 36
hours. In between these two features, strong southerly flow will
redevelop over the Alaska Range and the Interior by this evening
and will into early Wednesday before shifting to the southwest.

At the surface, a 973 mb low 150 miles southwest of Cold Bay will
rotate north into the southern Bering Sea and Bristol Bay region
tonight and then will remain quasi-stationary and weaken to a 999
mb low by Thursday morning. A ridge of high pressure will build
east over eastern Russia Monday. High pressure will persist over
the Arctic for much of the week.

Eastern and Central Interior...Leeside troughing north of the
Alaska Range will strengthen today as strong southerly flow
develops aloft. This will result in south gap winds in the Alaska
Range to increase through this evening. Gap winds will be the
strongest along the Richardson Highway in Isabel Pass where gusts
will peak around 70 mph late this evening into early Tuesday
morning. Gap winds will be weaker along the Parks Highway and in
the vicinity of Delta Junction. Have opted to upgrade the Wind
Advisory to a High Wind Warning for zone 226 given the expected
stronger gusts and kept the Wind Advisory for zone 223 as is. The
strong southerly chinook flow over the Alaska Range will bring
warmer temperatures, higher snow levels, and limit the potential
for precipitation across the southern Interior as a front moves
over the area tonight. To the north of Fairbanks, the front will
bring a mix bag of precipitation tonight through Wednesday.
Between Livengood and the Yukon River, the main precipitation
type will be freezing rain where up to one-tenth of an inch of ice
accumulation is expected. Have decided to convert the existing
winter storm watch for zone 220 to a winter weather advisory for
snow and freezing rain. North of the Yukon River, 4 to 8 inches of
snow accumulation is expected with the highest amounts in the
south upslope areas in the eastern Brooks Range. Have opted to
issue a Winter Weather Advisory for zones 218 and 219. Gusts up to
35 mph are possible over highway summits in zone 219, so blowing
snow and reduced visibility are expected. As the flow becomes
southwest Tuesday, precipitation will develop over the southern
Interior. Initially over the Central Interior precipitation type
will be freezing rain, but as temperatures warm it will change
over to rain. Should see rain taper off south of the Yukon River
by Tuesday evening and then to the north by Wednesday morning.

North Slope and Brooks Range...The next round of snowfall will
develop over the Brooks Range after midnight tonight and then
spread north of the North Slope east of Barrow Tuesday morning.
Over the northeastern Brooks Range, 5 to 7 inches are possible
with the heaviest expected east of the Dalton Highway and have
issued a Winter Storm Warning for heavy snow. Snow amounts along
the Arctic Coast will be between 2 to 6 inches, heaviest closer to
Barter Island. Easterly winds along the coast will increase this
evening becoming sustained 25 to 35 mph with gusts to 50 mph. With
fresh snow and gusty east winds, reduced visibility around one
half mile is possible in blowing snow. As such, have opted to
winter weather advisory for snow and blowing snow zones 203 and
204 starting Tuesday afternoon. Conditions will improve over the
eastern North Slope late Wednesday as both winds and snow taper
off. Over the western Arctic Coast and North Slope, snowfall
accumulations will be between 1 and 3 inches with this next round
of snow.

West Coast and Western Interior...As the front associated with a
low moving into Bristol Bay moves north today, rain showers will
spread north over the Yukon Delta and Lower Yukon Valley today,
reaching the Seward Peninsula tonight, and finally over Northwest
Alaska Tuesday morning. An unsettled, showery pattern will persist
over Western Alaska through late Wednesday as the aforementioned
low remains over Bristol Bay. Northeast winds will increase today
as the pressure gradient tightens over the Bering Sea and Bering
Strait. Gusts up to 55 mph are possible over St. Lawrence Island,
Bering Strait, and Point Hope by this evening. Gusty northeast
winds will continue for Point Hope through late Tuesday before
weakening; however, over St. Lawrence Island gusty northeast winds
will persist. At this time, it looks like the northeast wind
direction is not favorable for coastal flooding for the northern
shores of St. Lawrence Island with guidance showing a negative
contribution to storm surge after this evening and may see rough
seas offshore of St. Lawrence Island.

Coastal Hazard Potential Days 3 and 4...None; however, see West
Coast section above for issues in the shorter term.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Wind Advisory for AKZ223.

High Wind Warning for AKZ226.

Winter Storm Warning for AKZ206-AKZ220.

Winter Weather Advisory for AKZ203-AKZ204-AKZ218-AKZ219.

Heavy Freezing Spray Warning for PKZ240-PKZ245.

Small Craft Advisory for PKZ200-PKZ215-PKZ220-PKZ230-PKZ240-
PKZ245.

Gale Warning for PKZ210-PKZ225.
&&

LTH OCT 18