Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
531 PM EDT Tue Mar 17 2020
Valid 12Z Sat Mar 21 2020 - 12Z Wed Mar 25 2020
...Overview and Guidance/Predictability Assessment...
A late week deep Bering Sea storm will focus hazardous winds and
precipitation across portions of the mainland but begin to
gradually fill and lift poleward by this weekend. Several more
systems will then train across the region in the recurring
pattern, but predictability begins to drop considerably by day 6.
Expect moderate temperatures over the Interior/North Slope this
week, but remain cold enough to support periods of heavy snow,
with a particular risk for northwest Alaska. Meanwhile underneath,
additional but weaker system trough/jet energies will dig through
the Gulf of Alaska in a pattern with modest precipitation
potential for southern/southeast Alaska.
...Weather Highlights/Threats...
The WPC Alaskan medium range product suite valid Saturday through
Wednesday next week utilized the 12Z deterministic
ECMWF/GFS/CMC/UKMET through day 5 (Sunday) then with gradually
included higher weights of the 12Z GEFS/NAEFS/ECENS ensemble means
as model agreement and forecast uncertainty increased. This
methodology tends to mitigate less predictable small scale
variance from days 4-8 while also maintaining favorable WPC
forecast continuity.
Taylor
Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php
Hazards:
- Heavy snow across portions of mainland Alaska, Fri-Sat, Mar
20-Mar 21.
- High winds across portions of mainland Alaska, Fri, Mar 20.
- Much above normal temperatures across portions of mainland
Alaska, Fri-Tue, Mar 20-Mar 24.
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