Blizzard in Alaska, February 27 to 28, 2017

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
336 AM AKST Mon Feb 27 2017

.DISCUSSION...
The very busy weather pattern of the last week is settling down
with the transition from a progressive and and snowy pattern to a
blocked pattern with well below normal temperatures in the
forecast for northern Alaska next week.

The 00z model suite initialized well against the 00z surface
analysis and verified well against the 06z surface analysis. Model
spread remains very reasonable despite the ongoing significant pattern
change. Model spread remains reasonable through the end of next week.

Aloft at 500 HPA, an Omega Block centered over the Bering Sea forms
today and Tuesday as a strong shortwave trough over the west
coast of Alaska digs south and east with a deep upper level low
forming over the northern Gulf of Alaska by Tuesday morning
downstream of a high amplitude ridge that forms over the Bering
Sea. Most of northern Alaska will be on the cold side of the Omega
Block through this week and possibly through next weekend with
much below normal temperatures forecast for areas north of the
Alaska Range. The coldest temperatures are expected east of
Fairbanks. 850 mb temperatures over Fairbanks will drop from
around 12 below celsius this morning to around 20 below Tuesday
morning and drop further to around 22 below Wednesday, Thursday
and Friday. A core of even colder air with 850 mb temperatures
below 30 below is forecast to move south out of the high Canadian
arctic into eastern Alaska and the Yukon early next week with both
the GFS and the ECMWF bringing 850 mb temperatures of around 32
below and 1000 to 500 mb thickness values of around 488 DM over
Fairbanks area and 850 mb temperatures approaching 40 below and
1000 to 500 mb thickness values of around 474 DM over the north
slope by Tuesday morning of next week. Low temperatures are
forecast to drop to the 20s and 30s below in valley locations for
the central interior by the middle of this week with 30s and 40s
below possible in the coldest spots in the eastern interior by
late this week.

On the surface, a 1009 mb low over the eastern Brooks Range
combined with a 1043 mb high pressure system 300 NM northwest of
Wrangel Island will create a strong gradient over the eastern
north slope beginning tonight and continuing through the day
Wednesday. Recent snowfall combined with expected light falling
snow will combine for blizzard conditions developing tonight and
continuing through Wednesday over the eastern north slope. Over
the interior snow showers will continue with 1 to 3 inches
expected. 3 to 5 inches of snow are expected over the western
Alaska Range where upslope flow will enhance snow accumulations.
Scattered snow showers are expected today over the west coast.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Blizzard Warning for AKZ204.

Brisk Wind Advisory for PKZ200-PKZ210-PKZ220-PKZ225-PKZ245.
&&

CCC FEB 17