Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
648 PM EST Tue Feb 01 2022
Valid 12Z Sat Feb 05 2022 - 12Z Wed Feb 09 2022
...Overview...
A broad gyre located west of the Aleutian Chain will eject
multiple shortwaves through the Gulf of Alaska during the extended
period. A series of low pressure systems will spin up and track
toward the southern coast and the Southeast. Meanwhile, there will
be an upper high northwest of the Mainland that will retreat while
an upper low drifts toward northern Canada. Each low pressure
system will spread precipitation along the southern tier of the
state. There may be periods where the rain and snow become heavy
from the Kenai Peninsula to the southeast Panhandle.
...Guidance/Uncertainty Assessment...
A general blend of the models provide a good starting point given
that each of the solutions are very similar. Some model
differences arise with the second system, but a middle ground
solution is achieved by leaning more toward the CMC/ECMWF with
some GFS, EC ensemble and GEFS means. The latest runs of the
guidance continues to struggle with the upper ridge to trough
transition in addition to whether a blocky pattern returns by the
end of the extended period. Given this increased uncertainty, the
use of the means were increased in the blend.
...Weather/Hazard Highlights...
There will be three low pressure systems that trek northward
toward the southern coast and then onward to the Panhandle. Each
system will spread precipitation to the southern part of the
state, in the forms of multiple rounds of rain in the low/coastal
areas and heavy, wet snow in the higher elevations spanning from
the Alaska Peninsula to the Southeast into early next week. These
systems will also promote rough seas and strong, gusty winds in
the vicinity of the Aleutian Chain and the Alaska Peninsula.
Mostly dry and cold conditions are expected across northern parts
thanks to Arctic high pressure. Some snow showers over the
northern mainland may be possible early next week as the surface
high retreats. During this period the daily temperature readings
that have been below normal across a majority of the interior will
slowly return toward normal, while the North Slope remains below
normal.
Campbell
Hazards:
- Heavy precipitation across the Alaska Panhandle into the
southern coast of Alaska, Fri-Sun, Feb 4-6.
- Much below normal temperatures across portions of interior
eastern Alaska, Fri, Feb 4.
Additional 3-7 Day Hazard Information can be found on the WPC
medium range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php
WPC medium range Alaskan products including 500mb, surface
fronts/pressures progs and sensible weather grids can also be
found at:
https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml
https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html