Scientific Forecaster Discussion
Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
233 am akdt Thursday Oct 23 2014
Models...initialized well. Continue with very good run to run
continuity for the short term...but beyond Saturday is anyones
guess as the models continue to diverge...but not as much as a few
days ago when they were 180 out from each other. Will nudge to the
current forecast with a blend of the latest models for the short
Aloft at 500 hpa...a pair of 525 dam lows are merging over the
southern Gulf of Alaska this morning...and will weaken and move
southeast today. A weak trough of low pressure over the central
and eastern interior will move east as a weakening ridge over the
West Coast this morning moves to the central interior this
evening...then over the alcan border by Friday afternoon...then
into the Yukon territories. A trough extends southeast then south
from a 499 dam low over eastern Siberia this morning and will move
over the western interior by Friday morning...and to the alcan
border by Saturday morning...then into the Yukon territories. A
524 dam low over Barrow will move north and be absorbed by the
expanding low over Siberia. At 850 hpa...weak warm air advection
next 24 to 36 hours across the area.
On the surface...a 1038mb high near 80n 170w will move west this
afternoon. Broad area of cyclonic flow over the state will finally
move south out of the areas as a weak ridge moves to the interior
from the West Coast today and tonight. A 1002mb low will develop
over Prince William Sound late tonight and persist into Saturday
before moving southeast and dissipating. A weather front extending
from a 971mb low over eastern Siberia will move to St Lawrence
Island this morning...then over the West Coast this afternoon. The
front will slowly dissipate as it move across the central and
eastern interior. Models currently show storm surges of less than
2 feet on the coast with the first wave. A second wave will move
to the West Coast Saturday morning with similar forecast surge.
Models are showing a fetch the length of the Bering Sea which
persists for about 36 hours before is starts breaking down. This
could generate winds waves of 13 to 20 feet offshore.
Arctic coast and Brooks range...winds down from the last few
days...but winds 10 to 25 miles per hour persisting across the areas even as
they swings around to the southeast and south today and tonight.
Weak trough developing over the plains and offshore flow should
help clear things up a bit. Expect ceilings to come up a bit
today and maybe some breaks in the clouds during the afternoon
and overnight. Flurries and some patchy fog along the coast...but
overall conditions improved.Trough remains over the area into the
weekend then drifts just offshore Saturday. Still not looking for
much change in temperatures through the weekend.
West Coast and western interior...front will move over St
Lawrence Island this morning and to the West Coast by around noon
today. Precipitation starts as snow this morning then changes to
rain on the island by afternoon. Once it makes it to the coast
precipitation will remain snow north of Norton Sound...but will
mix with rain to the south. As the front makes its way inland
precipitation will remain all snow. Precipitation amounts of 0.25
to 0.50 will occur near the coast with lighter amounts inland.
Snowfall of 2 to 4 inches with the heaviest amounts over the
interior Seward Peninsula and the Nulato Hills. Coastal areas
will see up to 2 foot of storm surge as the system comes ashore.
Southwest to west winds will persist behind the front with waves
near shore building to 4 to 8 feet. Will continue the high surf
advisories. A second weather front will move to the coast on
Friday morning spreading more rain and snow up the coast...but
not much to the inland areas east of the Nulato Hills...and a
third front will move onshore Sunday.
Central and eastern interior...mix of sun and clouds across the
interior today in advance of the weak frontal system that will
move through the area Friday afternoon and evening. Not expecting
a lot of snow as the system moves through but many areas will get
1 to 2 inches of snow Friday night into Saturday morning. Light
winds across the area through the weekend. Temperatures steady
through Saturday...then some slight cooling as we move into next
Coastal hazard potential days 3 and 4...potential for high surf
will remain through the weekend as extended persistent fetch over
the Bering Sea will produce near shore waves of 4 to 8 feet.
High surf advisory for akz207-akz209-akz211-akz212-akz213-akz214.
Heavy freezing spray warning for pkz230-pkz235-pkz240-pkz245.
Small Craft Advisory for pkz200-pkz215-pkz220-pkz225-pkz230-
Gale Warning for pkz210-pkz235-pkz500.
Sdb Oct 14