Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
507 PM EST Wed Dec 08 2021
Valid 12Z Sun Dec 12 2021 - 12Z Thu Dec 16 2021
...Another Major Storm for Alaska...
...Overview and Guidance Evaluation/Preferences and Weather/Hazard
Highlights...
A deep low pressure system over the Bering Sea will track toward
the Southwest Alaska, the Alaska Peninsula/Kodiak Island before
redeveloping into a potent low near the Kenai Peninsula by Friday.
This feature will impact a major of the state by ushering in
strong wind, cold temperatures and/or scattered to widespread
precipitation. Following in its path is yet another system,
tracking over the eastern Gulf of Alaska over the weekend/early
next week. This potent storm system will pack a punch, spreading
the threat of high winds, Gulf waves along with heavy coastal
rains and terrain enhanced heavy snows from south-central Alaska
to the southeast Panhandle. Much below normal temperatures will be
settled in over much of the southern half of the state after it
the system passes. For specifics on the expected hazards, refer to
latest WPC Day 3-7 Hazards Outlook product listed and linked
below.
Overall the favored model blend consisted of the 12Z
CMC/UKMET/ECWMF/GFS(06Z/12Z) through most of the extended period,
tipped slightly toward the GFS as well as including the ECWMF
ensembles and GEFS mean through the middle and later periods. The
GFS has a solution that is more on the bullish side than the
others, however it gives a more progressive, southern track with
deeper lows than some of the other solutions. The ECWMF starts to
become more amplified by Tuesday night/Wednesday morning and
diverging from the cluster.
Campbell
Hazards:
- Heavy snow across portions of southwestern Alaska, Mon-Tue, Dec
13-Dec 14.
- High winds across portions of southwestern Alaska, Alaska
Peninsula and the eastern Aleutians, Sat-Sun, Dec 11-Dec 12.
- Much below normal temperatures for the southern half of Alaska
including the Alaska Peninsula, Sat-Mon, Dec 11-Dec 13.
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