Blizzard in Alaska, February 14, 2017

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
359 AM AKST Tue Feb 14 2017

.DISCUSSION...

Models...Good run to run continuity the last couple days. They
initialized well against the 14/06Z surface analysis. Good
agreement on position and only a millibar or two difference on the
central pressures. There is better agreement today into the
midrange than there was yesterday but they still diverge quite a
bit in the extended periods. Will lean on an equal blend of the
00Z model runs for the near term today. Temperatures remain
difficult as they will warm significantly again today so that will
make the model diurnal trend almost useless, so will need to
manually force them.

Aloft...At 500 hpa...486 dam low is 150 nm south of Sand Point and
will rotate back to the north to be over Bristol Bay by Wednesday
morning at 988 mb, then moves northeast to 100 nm north of King
Salmon over the Nushagak Delta by Thursday morning. By Friday
morning it will merge with another low over Norton Sound with a
500 dam center and a trough extending south to a low near Dutch
Harbor. The ridging over the southeast interior has shifted to the
north a bit with the axis extending from over Dawson YT to
Deering. The ridge will be pushed back into Canada a bit as a
shortwave moves up the western flank of the ridge over the state
today. The shortwave is over the gulf coast this morning and will
lie from Togiak to McGrath to Fairbanks to Dawson this afternoon,
and from Togiak to Anvik to Bettles to Komakuk Beach YT this
evening then the western portion merges with the trough over the
west coast and the eastern half moves northeast into the Canadian
arctic. The ridge will build back in behind the shortwave and the
axis will lie from Kaltag to Delta Junction to Carmacks YT
tonight, and from Elim to Fairbanks to Dawson YT by Wednesday
morning. The ridge will continue to slide north and will lie from
Buckland to Old Crow YT Wednesday evening. A second shortwave
rotating around the low over the southwest will move to the Gulf
coast Wednesday evening and move into the interior Thursday
morning. At 850 hpa...No changes here, the zero isotherm makes an
appearance over the interior and pushes north to lie from Old
Crow YT to Fairbanks to Mcgrath this morning then recedes back
into Canada tonight.

Surface...Broad area of cyclonic flow around a 957 mb low 100 nm
east of Kodiak City covers all but the arctic coast this morning,
and will persist through the week as the low eventually moves over
the southwest mainland as it slowly fills. Northeast gradient
winds have developed ahead of the front over some higher elevation
areas, and aligned valleys will also see some higher winds in all
the interior zones and that will persist into late this evening
before they diminish. Ridging extends east from a 1023 mb high in
siberia over the arctic coast. Leeside troughing has developed
north of the Alaska Range and the Tanana Valley jet has set up in
the Delta Junction area. A warm front has moved north to lie from
Dillingham to Farewell Lake to Fairbanks to Chalkyitsik this
morning and will continue to move north to eventually lie
northeast across the state from Bethel to Old Crow YT this
evening, then slowly moves north and west as it dissipates by
Wednesday evening. A second front will move into the southern
interior Wednesday evening and slowly move north and west again as
it weakens. The northern half will eventually move off to the
northeast while the western half will merge with a trough over the
western interior Thursday night. Gap flow winds in the Alaska
Range today with the strongest gradient across the eastern Alaska
Range east of Healy and west of the Tok Cutoff. Weak ridging north
of the Brooks Range will persist through Thursday.

Arctic Coast and Brooks Range...Decaying front over the northwest
coast will leave some stratus behind, and maybe a few flurries
today, otherwise cooling temperatures from Point Barrow west. To
the east of Point Barrow some light snow will spread west across
the area slowly through the day. The GOES MVFR Probability product
at 14/1015Z indicating quite a bit of MVFR conditions over the
coastal areas and arctic plain. Observations indicate low ceilings
have moved over much of the area, so expect them to persist with
a few breaks, and they may lift a bit when the snow moves in.
Temperatures cooling from Point Barrow west today as some colder
air advects into the area. Slightly warmer to the east as the
decaying warm front over the interior moves into the area. Winds
will be all over the dial today but mainly north from Point
Barrow west and southwest to the east. Wind speeds generally 10 to
20 mph with the strongest winds east of Deadhorse.

West Coast and Western Interior...Biggest issue will be the winds
again today, along with the potential for ground blizzard
conditions in the Bering Strait and on St Lawrence Island. Will
issue a Winter Storm Warning for zone 213. Winds will remain
strong through the remainder of the week over the Bering Strait
with relatively strong winds in Norton Sound and the Chukchi Sea.
Inland areas will see northeast winds 5 to 20 mph locally gusting
to 30 mph though some higher elevation will see stronger winds to
near 40 mph today. Expect some flurries and fog with the stratus
over the Bering Strait and St Lawrence Island with no significant
accumulation. In the lower Yukon Delta snow is developing and will
spread northeast as the trough sets up. Accumulations of 2 to 5
inches can be expected through Wednesday morning in the middle
Yukon Valley and lower Yukon Delta with lesser amounts to the
north and west as the front slowly moves into those areas as it
dissipates.

Central and Eastern Interior...Weather front moving across the
area today with a trough setting up to the north and west of the
Tanana Valley. A slight chance of some freezing rain as the front
passes through the area, but no accumulation expected. The
heaviest snow will be to the west and north of Fairbanks with 2 to
4 inches possible. The heaviest snow will occur in the upper
Yukon Flats and the upper porcupine river. There continues to be a
slightly better chance of freezing rain in the Alaska Range and
along the leeside of the range south of Fairbanks, but expect the
models are overdoing the precipitation and it will be chinooked
out. Strong winds continue in and around Delta Junction as the
Tanana Valley jet has set up with the leeside trough and low over
the Tanana Flats, and ridging to the east. Gap flow winds
developing in the eastern Alaska Range today will be gusting to
around 65 mph so will issue a Winter Storm Warning for the winds
and near blizzard conditions possible near the passes.
Temperatures continue to rise today with highs around Fairbanks in
the mid 30s. They will continue to be warm Wednesday but may fall
a couple degrees as some cooler air filters into the area from
the west.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Wind Advisory for AKZ223.

Winter Storm Warning for AKZ213-AKZ226.

Winter Weather Advisory for AKZ214-AKZ218-AKZ219.

Gale Warning for PKZ210-PKZ220.

Brisk Wind Advisory for PKZ225.

&&

SDB FEB 17

Special Weather Statement
National Weather Service Fairbanks AK
254 AM AKST Tue Feb 14 2017

AKZ221>226-150300-
Central Interior-Middle Tanana Valley-Deltana and Tanana Flats-
Upper Tanana Valley and the Fortymile Country-Denali-
Eastern Alaska Range-
Including Nenana, Anderson, Tanana, Minto, Manley Hot Springs,
Rampart, Lake Minchumina, Livengood, Fairbanks, Fort Wainwright,
Eielson AFB, Ester, North Pole, Moose Creek, Two Rivers, Fox,
Chatanika, Chena Hot Springs, Sourdough Camp, Salcha,
Delta Junction, Fort Greely, Harding/Birch Lake, Dry Creek,
Dot Lake, Healy Lake, Tok, Tanacross, Eagle, Tetlin, Northway,
Alcan, Chicken, Boundary, Healy, Denali National Park,
Carlo Creek, Kantishna, Mentasta Lake, Black Rapids,
Donnelly Dome, Trims DOT Camp, Eagle Trail, and Mineral Lake
254 AM AKST Tue Feb 14 2017

...WARMER TEMPERATURES AND SLICK ROADS IN THE INTERIOR...

Warm moist air continues to flow north into the interior and it
will send temperatures today into the 30s above and that will
produce slippery road conditions as frost develops on the paved
surfaces.

Temperatures in the Tanana Valley east of Tanana and from Fox
south will rise into the 30s with temperatures in the remainder of
the area north and west to the Yukon River well above zero.
Highs in the Fairbanks area will be in the mid 30s with a few
areas to the south approaching 40 degrees.

Road surfaces remain frozen and as the warm air moves over them
frost will develop, especially on low traffic and shaded roads,
creating slick driving conditions. Conditions may improve during
the overnight hours as temperatures fall. These conditions are
expected return each day through midweek.

For the latest forecasts go to www.weather.gov/fairbanks