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Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
444 am akst Sat Jan 21 2017

Discussion...

Models...big picture they initialized well on positioning, but
about 4 mb low on the ridge to the east at 21/06z. There is
concensus on cold air diving into the area behind the light
snow/flurries this morning as it clears. The question is just how
cold it will get and the models are several degrees apart on that
but they have similar timing. They stay instep through around 96
hours before the shortwaves really get messy.



Aloft...at 500 hpa...488 dam low 100 nm northeast of Point Barrow
anchors the long wave trough and will move north to 80n later
this morning. A shortwave will lie over Cape Halkett to the lower
Yukon Delta this morning, and over the Beaufort Sea and alcan
border south to The Porcupine river this afternoon. Troughing will
persist over the West Coast and western interior as a 500 dam low
near St Lawrence Island will move over Nunivak Island this
afternoon, and over Kodiak city by Sunday morning. Ridging will
persist over the areas south of The Porcupine river and east of
Tanana through Sunday. The low over Kodiak city will fill and an
associated shortwave will push northeast into the ridge and lie
from Ambler to Cordova late Sunday and continue northeast moving
into Canada and the eastern Arctic Monday evening. A ridge over
the central Aleutians today will move over the eastern Bering Sea
south of St Matthew island by Sunday afternoon, and over the
Mainland south of the Tanana river by Monday morning. A 500 dam
low will develop over Kotzebue Sound Sunday afternoon. A 497 dam
low will move to the central Aleutians by Monday morning. At 850
hpa...the 20 below isotherm will move southeast to lie from Old
Crow to Delta Junction then southwest this morning and stalls,
then starts moving back to the northwest Sunday.

Surface...slowly moving front is inching its way east across the
interior this morning but expect it will stall over the central
interior as the surface ridge pushes back to the west today.
Otherwise ridging will persist over much of the state with a 1025
mb high center over the Yukon territory persisting in some form,
and 1028 mb high persisting over Siberia. A cold front associated
with the 990 mb low high in the Arctic has moved to the northwest
coast and will make a glancing blow over the coast as it moves
northeast.

Arctic coast and Brooks range...front makes a glancing blow over
the area and will spread some light snow or flurries to the
coastal areas today. Wind chill is still an issue and that will
continue into the evening when winds diminish. Expect temperatures
to fall a couple degrees as more cold air filters in from the
northwest. Npp viirs sport nighttime microphysics product showing
stratus over most of the Arctic moving around the low and that
matches up with what can be seen on the GOES products this
morning. Winds continue at 10 to 15 mph from the southwest today
and diminish this evening to less than 10 mph.

West Coast and western interior...not much going on out here, a
weak low has developed over Kotzebue Sound and stratus had
developed and is spreading flurries over the region. Expect a few
clouds to move south over the coast today, but flurries should
remain north of the Seward Peninsula. A few clouds will also make
it into the upper Noatak and Kobuk valleys, but again not
expecting any significant snow. The western interior and lower
Yukon Delta will remain virtually cloud free today and tonight so
expect temperatures to remain very cold with some -50 temperatures
possible today and tonight. Temperatures will start warming late
Sunday. No significant winds.

Central and eastern interior...pretty tricky forecast. The
decaying front/convergence zone will not be moving very much, so
hard to determine which areas will clear and which will stay
cloudy. Expect the flurries to taper back a bit, but there is a
constant feed of moisture from Cook Inlet north into the interior
through this evening. Still expect clouds to hang around between
Manley Hot Springs to Eagle. From Tanana to Allakaket to Bettles
to Coldfoot expect temperatures to fall to near 50 below. Lows in
the upper Tanana Valley will be in the 40s below. Most other areas
will see temperatures fall into the 30s below. Winds generally
light.

&&

Coastal hazards days 3 and 4...none.

&&

Afg watches/warnings/advisories...

Wind Chill Advisory for akz201-akz202-akz204-akz205.

Wind chill warning for akz203.

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