Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
616 PM EDT Thu Apr 21 2022
Valid 12Z Mon Apr 25 2022 - 12Z Fri Apr 29 2022
...Guidance/Predictability Assessment...
12 UTC GFS/ECMWF/UKMET/Canadian medium range model guidance seems
well clustered into Day 4/5 (Mon/Tue) and a composite seems
reasonable despite embedded smaller system differences that tend
to be mitigated via the blending process consistent with a pattern
with near average predictability. Switched to compatible 12 UTC
GEFS/ECMWF ensemble means for the remainder of the medium range
period (Wednesday-next Friday) amid gradually growing forecast
spread. This plan maintains good WPC product continuity and in the
larger sense is closer to the ECMWF than the Canadian or GFS. The
Canadian develops more upper troughing with time over the mainland
and the GFS is more progressive with Pacific low pressure systems
into lead upper ridging over the west/southwest Alaska next week.
...Overview Weather/Hazard Highlights...
Lingering low pressure systems over the eastern Gulf of Alaska
next week will continue some light to locally moderate
precipitation across the southern Coast and mainly the Panhandle.
Activity should wane with time as the main lead low weakens and
pushes into western Canada. Light to moderate precipitation will
also progress across the Aleutians and the Alaskan Peninsula
associated with a couple of frontal systems through the period and
broad troughing/main low pressure center focus shifting through
the Bering Sea. Most of the Mainland should remain dry, save for
some scattered activity into the west coast ahead of Bering Sea
troughing and locally over the Interior with uncertain upper
impulse/trough developments. Temperatures across the Mainland
should be mostly above normal pending these developments. Southern
regions, from the Aleutians to the Panhandle, should remain near
or below average owing to increased clouds and precipitation.
Schichtel
Hazards: No significant hazards are expected over Alaska during
this forecast period.
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