Scientific Forecaster Discussion
Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
341 am akdt Friday Oct 24 2014
Models...good run to run for the very short term...but models
showing quite large differences beyond 36 hours. The one thing
they have in common is that the pattern will remain progressive
with no shortage of shortwaves. Nudging to the current grids with
a blend of the latest models again today...but will lean a little
heavier on the European model (ecmwf) beyond 36 hours since it has been doing a
much better job of late in the Middle Range.
Aloft at 500 hpa...a 536 dam low west of the Queen Charlotte
island will continue to weaken and move east into Canada. A weak
ridge will continue its March east into the Yukon this morning.
Series of shortwaves will move around a 497 dam low over eastern
Siberia...the first will weaken as it continues across the middle
Yukon valley this morning...to the central interior by this
afternoon...and into the eastern interior by early Saturday
morning. The second wave will move to the coast this morning then
continue east...the third will make its way to the coast on
Saturday morning...and a forth will get to the coast Sunday as the
low and long wave trough reorient over the West Coast with ridging
building over the eastern half of the state. At 850 hpa...not much
change under the zonal flow until the ridge starts building over
the eastern interior on Sunday...then some warm air advection.
On the surface...the high that has been near 80n for over a week
has finally moved west...but weak ridging remains over the Arctic
Ocean through Saturday morning. A dissipating occlusion will move
from the middle Yukon valley east to the Yukon territory by
Saturday morning. A second front developing over the eastern
Bering Sea will move over the West Coast this morning and into
the middle Yukon valley this evening...then dissipate over the
upper Koyukuk basin and central Brooks range Saturday evening. A
third frontal system will move to the Bering Strait tonight and
move over the West Coast Saturday morning...moving through the
middle Yukon valley late Saturday and dissipating over the
Kuskokwim Mountains Sunday morning. The most potent of the fronts
will move to the West Coast on Sunday morning and move to the
middle Yukon Sunday evening. With the ridge building over the
eastern half of the state will keep most of the precipitation with
this last front west of Tanana.
Arctic coast and Brooks range...easterly to southeasterly
offshore flow will continue over the area through the weekend.
Winds will be in the 5 to 20 miles per hour range. Still expect some
occasional snow showers or flurries and areas of fog. West of
Barrow and in the western Brooks range expect periods of snow with
accumulation through the weekend of 2 to 8 inches. No significant
changes in temperatures through the weekend.
West Coast and western interior...will be a mess as the series of
fronts move through the area. Timing will be difficult but models
seem to have a reasonable handle on them...at least in the short
term. Weather front yesterday dropped up to 3 inches of snow with
mixed rain and snow south of the Seward Peninsula. Expect much of
the same over the weekend with each front bringing up to 3 inches
of snow to most areas. The front Saturday morning could dump
around 5 inches of snow on the southern Seward Peninsula
mountains and in the Noatak and Kobuk valleys as well as the
south slopes of the western Brooks range. On Sunday it looks like
a replay of Saturday. West winds along the coast today become
south this afternoon...then southwest Saturday. Strongest winds
will be Sunday night into Monday...but winds will be persistent
through the weekend in the 5 to 15 miles per hour range increasing to 15 to
25 miles per hour as each front moves through the area. Winds Sunday night
through Monday will top out at 25 to 35 miles per hour gusting to 45 miles per hour.
Models still showing a storm surge of 1 to 3 feet through the
weekend. Will maintain the high surf advisories for zones 211-214.
Central and eastern interior...clouds and flurries under the dirty
ridge will be pushed east as the dissipating front is driven east
by the upper level shortwave. Snow moving in with the front and
expect up to an inch of snow over most of the area through this
evening. Remainder of the weekend snow looks like it will remain
mainly to the west of Manley Hot Springs. Looking like winds will
be less than 10 miles per hour through the weekend. Not much change expected
in the temperatures through Monday.
Coastal hazard potential days 3 and 4...looking like good
potential for high surf Sunday night through Tuesday with 2 to 5
foot storm surge...but models at this range continue to
disagree...so it will be something we have to keep an eye on.
High surf advisory for akz211-akz212-akz213-akz214.
Small Craft Advisory for pkz200-pkz210-pkz220-pkz235.
Heavy freezing spray warning for pkz235-pkz240-pkz245-pkz500.
Sdb Oct 14