Scientific Forecaster Discussion
Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
616 am akst Tuesday Mar 3 2015
upper level ridge extending from the eastern Yukon territory to the
southern Yukon territory and southward will flatten out as it
moves farther eastward into Canada today. A short wave trough over
the western Bering Sea will move eastward to longitude 140w by Wednesday
morning...gradually dampening out during the period. Weak ridging
will temporarily rebuild behind the short wave. The next short wave
in the current series will move eastward to the northern Bering
Sea by late Wednesday night...then moving eastward to the alcan border
by Friday afternoon...putting a Dent in the ridge aloft over the
northern Alaska Mainland. West southwest flow aloft over northern
Alaska will increase Friday evening and Friday night as a stronger short
wave moves to the northern Bering Sea late Friday night. This pattern
is favorable for significant snowfall over much of northern Alaska
south of the Brooks range. This short wave will gradually deepen
into a major trough while decelerating through Monday morning...with
the trough axis then lying along the alcan border and southward.
The deepening trough will bring substantially colder aloft and at
the surface to the western parts of northern Alaska by sun and to
the eastern parts by Monday.
a 1002 mb low about 50 miles north of Cape Lisburne will
curve eastward across the Beaufort Sea...deepening to about
a 998 mb center 200 miles north of Demarcation Point by Wednesday
morning...then continuing eastward into the Canadian archipelago.
As the low tracks eastward across the Beaufort Sea...strong west
winds will develop along the Arctic coast and northern plain of
the Arctic slope...beginning late this afternoon over the extreme
western areas and expanding eastward tonight. Blizzard conditions
are expected to develop over the central and eastern Arctic coast
this evening and continue through Wednesday. Reduced visibility in snow
and blowing snow will be experienced along the central and western
Arctic coast...and over the northern plain of the Arctic slope.
The passage of the short wave aloft and the surface cold front
will bring a period of snow. The heaviest amounts...2 to 3
inches...will be experienced over the western Arctic coast...
northwestern Brooks range and western interior areas of the Arctic
slope. Winds with this event will not be as strong as those
experienced in the previous event due to a weaker pressure
gradient and weaker pressure rises and cold advection behind the
Snow over the West Coast will spread eastward across the
interior through this evening as the short wave trough aloft
moves east...providing large scale lift and shifting the flow
aloft to westerly. Snow could be mixed with rain in Denali
with temperatures aloft warm enough. A leeside trough north of
the Alaska Range will weaken this afternoon...resulting in
diminishing winds through Alaska Range passes.
There will be potential for significant snowfall over the West
Coast Friday and Friday night...and over much of the interior south of
the Brooks range Friday night into Sat night with the fast and
moist west to southwest flow aloft and the strong short wave
trough deepening as it moves eastward across northern Alaska.
Wind Advisory for akz226.
Blizzard Warning for akz203-akz204.
Winter Weather Advisory for akz201-akz202-akz205-akz206.
Brisk Wind Advisory for pkz200-pkz210-pkz215-pkz220-pkz225-
Rf Mar 15