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Northern Alaska forecast discussion 
National Weather Service Fairbanks Alaska
232 am akst Wednesday Dec 17 2014

Discussion...

Models...good run to run continuity. Models continue with similar
solutions out to around 60 hours with the latest runs. Surface
positions initialized well against 06z analysis...but models have
the low in the eastern Bering Sea slightly weaker than I analyzed
it. Not seeing any significant pattern change in the models until
at least the middle of next week. A nudge with a blend of the
current models to the existing grids will be the way we work the
forecast again today.

Aloft...at 500 hpa...ridge nudging in from the east over the
state has broken down a little as shortwave moves north across the
area. As the closed low over the eastern Bering Sea weakens and
moves west ridging redevelops over Mainland Alaska by Thursday
morning and persists into the weekend. The 501 dam closed low over
the eastern Bering Sea continues to slowly move west through
Friday as it slowly weakens and eventually dissipates in the north
central Bering Sea over the weekend. A 508 dam low 500nm south of
Sand Point Wednesday morning will be 500nm south of Prince William
Sound by Thursday morning...then weakens as it moves over the
central Gulf of Alaska before being absorbed by a broad area of
low pressure over the central Aleutians. At 850 hpa...models
indicating temperatures will be fairly steady over the next few
days with the exception of the Arctic coast and plains which will
see some weak warm air advection.

Surface...the general scenario has not changed much over the last
few days...with high pressure over Siberia and the Arctic and a
broad area of low pressure over Mainland Alaska and adjacent
areas. Gradient continues to be fairly strong over and near the
Bering Strait...but is is weakening and wind speeds are on a
general trend down. Pressure gradient over Mainland Alaska is
pretty benign right now but as the low in the North Pacific moves
in the the Gulf of Alaska expect winds to generally increase from
the northeast...but not significantly. Winds around the Bering
Strait will continue to be problematic as the gradient weakens
today and tonight...then strengthens over the area again Thursday
afternoon.

North Slope...continued relatively quiet...but Arctic boundary
flopping around over the area will provide some forecasting
challenges dependent on where it lies. Fog...flurries...blowing
snow...low clouds...will all come into play at times along the
coast. About the only constant will be the northeast winds that
persist at 10 to 20 miles per hour. The Arctic boundary should move north of
the coast by Friday afternoon...so expect slight improvement
then...until that time conditions across the area will be quite
variable. Temperatures aloft will be on the rise today so expect
surface temperatures to be pretty steady the next 24 hours...then
start rising.

West Coast and western interior...improving trend as the low
slowly moves west. Gradient has really slackened up over the past
12 hours and expect that to continue through tonight...but
gradient strengthens over the Chukchi Sea and Bering Strait again
Thursday. With Arctic boundary hanging around expect some snow
showers mainly north of the Strait today...tapering off tonight.
Inland areas will be pretty quiet with just some patchy fog and
clouds. Expect northeast to east winds to pick up across the
higher elevations in the area Thursday as the low in the Gulf
interacts with the high in the Arctic. Not much temperature change
expected until next week.

Central and eastern interior...a few flurries from Fairbanks
north this morning as the upper level trough moves across the
area. May even see a period of snow in z218...z219...and
z220...but not expecting much more than an inch of accumulation.
Winds will generally be light...with the exception of z226 which
is getting some gusty winds to around 40 miles per hour this morning. Expect
they will diminish pretty rapidly this morning as the gradient
slacks off. A general downward trend in temperatures...but not
anything significant...just trending toward normal for this time
of year.

&&

Coastal hazard potential days 3 and 4...none

&&

Afg watches/warnings/advisories...

Heavy freezing spray warning for pkz210.

Gale Warning for pkz210-pkz225-pkz230.

Brisk Wind Advisory for pkz235-pkz240-pkz245.

&&

$$

Sdb Dec 14

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