Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
532 PM EST Thu Feb 10 2022
Valid 12Z Mon Feb 14 2022 - 12Z Fri Feb 18 2022
...Major Aleutians Storm Early Next Week...
...Guidance/Predictability Assessment...
The 12 UTC GFS/ECMWF are best clustered for details days 4/5
(Mon/Tue), especially the monster low near the Aleutians, and have
decent overall support from the other models and ensembles for
both offshore lows and general upper troughing and cooled lower
atmospheric air over the North Slope and northern Interior.
Predictability stays above normal for days 6-8, but forecast
spread with some of the embedded features still favors a more
compatible GEFS/ECMWF ensemble mean blend along with some manual
edits to preserve better offshore low depth.ÂWPC product
continuity with this plan seems well maintained, with the most
uncertainty mid-late next week associated with Aleutian proximity
of deepened lows and southern tier QPF spread.
...Weather/Hazard Highlights...
Forecast confidence is high that a powerhouse and slow moving
Aleutian storm slated to intensify below 960 mb will present a
threat of high winds/waves and wrapping heavy precipitation early
next week. Several pieces of guidance show gusts near hurricane
strength are possible. Subsequent deepened low threat potential
will continue into mid-later next week given favorable support
pattern, albeit with less certain track/details. Strong flow
between these deep lows and around the periphery of an amplified
northeast Pacific ridge will also provide a conduit for a deeper
moisture and precipitation focus from the AKpen/Southwest Alaska
through Southern/Southeast Alaska, locally enhanced as
systems/energies break downstream through the period. Moderate to
locally heavy snow will be enhanced by terrain, with rains more
likely closer to the coast.
Meanwhile, much of the Interior/North Slope should start out
chilly, but slowly moderate next week. The southern third of the
Mainland should be in a warming trend through much of the period
as an upper level ridge builds into the region. Daytime highs near
10-20 degrees above normal are possible, with overnight low
anomalies even greater.
Schichtel
Hazards:
- Heavy precipitation across portions of the Alaska Panhandle,
Wed-Thu, Feb 16-Feb 17.
- High winds across western Aleutians, Sun-Mon, Feb 13-Feb 14.
- Much below normal temperatures across portions of western
Alaska, Sun-Tue, Feb 13-Feb 15.
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