Scientific Forecaster Discussion
Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
450 am akst Friday Nov 21 2014
Fairly tranquil weather will dominate most of northern Alaska
through the weekend before transitioning to a more active pattern
middle to late next week. Latest suite of deterministic models are in
good agreement through early Tuesday with model solutions
Broad upper level low complex and its 958 mb surface reflection
continue to wobble over the Alaska Peninsula. Models have both the
low aloft and at the surface remaining over the Alaska Peninsula
and wobble around while gradually weakening through the weekend.
1031 mb surface high over the Arctic this morning will gradually
slide south and east through the weekend. By early next
week...another upper low and its surface reflection will move into
the Bering from the Kamchatka peninsula. What happens to it middle
to late next week is unclear since long range model solutions
handle the progression of this low differently. There is a glimmer
of hope for snow over the interior late next week as the 00z GFS
hints at the remote possibility of some snow...while the 00z ecwmf
wants to continue the dry spell for a bit longer.
An occlusion associated with the 959mb surface low over the Alaska
Peninsula will rotate north and onshore later this morning...and
northward to the interior by this evening. The pressure gradient
between the surface high over the Arctic and low over the Alaska
Peninsula will strengthen over the interior as the occlusion
moves north. Winds over the interior uplands and usually channeled
areas will pick up by the afternoon gusting to 40 miles per hour and persist
through Saturday. Will be including strong wind headlines for
some interior zones through the tonight period. A High Wind
Warning will issued for zone 219 where Summit observation are already
reporting gusts to 50 miles per hour. No snow is expected with this
occlusion over the interior. Another frontal wave is prognosticated to
rotate north over the interior Saturday. With this wave...models
are wanting to paint some light snow over the interior.
However...thinking it will fizzle out as it encounters the dry
airmass over the interior...producing flurries at best.
Persistent fog...dense at times...across the upper Tanana Valley
will improve later this afternoon as the occlusion moves overhead.
MOS guidance has visibility gradually improving through today.
Near blizzard conditions continue for parts of zone 203 this
morning where there is an existing Winter Weather Advisory for
blowing snow. Both deadhorse and nuiqust are reporting blowing
snow and visibilities less than one half mile...so will continue
Winter Weather Advisory as is for zone 203. Surface observations
from zone 204 have shown that conditions have improved quickly
even though winds remained sustained from 35 to 45 knots with
gusts to 53 knots. Will drop the Blizzard Warning since criteria
is no longer being met and then will headline strong winds in zone
204. East winds 20 to 40 miles per hour with higher gusts will persist from
Barrow east through at least Saturday afternoon. A strong wind
headline will also be included in the forecast for zone 202.
Temperatures across northern Alaska will be trending down towards
normal through the forecast period as colder h850 temperatures
slowly trickle southward over the period and an overall decrease
of 5 to 10 c will be seen across the area.
Coastal hazard potential days 3 and 4...none
High Wind Warning for akz219.
Winter Weather Advisory for akz203.
Small Craft Advisory for pkz200-pkz210-pkz220.
Gale Warning for pkz240-pkz245.
Brisk Wind Advisory for pkz230-pkz235.
Lth Nov 14