Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
624 PM EDT Sat Apr 16 2022
Valid 12Z Wed Apr 20 2022 - 12Z Sun Apr 24 2022
...Two major storms for the Aleutians and Gulf of Alaska next
week...
...Guidance/Predictability Assessment and Weather/Hazard
Highlights...
The foremost focus of significant systems next week will be near
the Aleutians and over the Gulf of Alaska. Deep and moist low
pressure originally associated with Typhoon Malakas should track
over and then southeastward from the Aleutians over the next few
days, bringing strong winds, enhanced precipitation and maritime
threats. It will then track well offshore into the far southern
Gulf of Alaska and northeast Pacific into mid-later next week as a
maritime threat. This will set the stage for quite a stormy
upcoming week. The medium range guidance signal is steadily
growing in support for development of new and dynamic deep low to
track toward the Aleutians into mid-later next week on the heels
of the lead storm. In comparison, this second powerful low does
not have a tropical origin and will be slated to subsequently work
more into the northern Gulf of Alaska into later next week/next
weekend along with a potent closed upper low/trough. This would
also up the wind/wave/precipitation threat ante for the Alaskan
Peninsula, Kodiak Island and the southern tier of Alaska that
should not be significantly affected by the lead system. Overall,
the 12 UTC GFS/ECMWF solutions seem best clustered and enjoy ample
ensemble support. Accordingly, WPC product guidance for days 4-8
(Wed-next Sunday) have been derived mainly from the 12 UTC
GFS/ECMWF along with smaller than normal inputs from the 12 UTC
GEFS/ECMWF ensemble means through the forecast period in a pattern
with above normal predictability.ĀThis guidance strategy also
fits the general flow pattern expected over North Slope and
Interior comprised mainly of an initially amplified but slowly
weakening upper ridge over the north and a less defined upper
weakness/trough settling over the south-central Interior. In this
pattern, much of these areas should remain fairly dry with at most
very light/scattered precipitation. In general expect above
normal temperatures over most of the northwestern half of the
mainland and below normal readings over the southeastern half of
the mainland and the Panhandle. WPC product continuity seems well
maintained across much of the domain with this overall solution,
albeit with a trend for deeper main offshore lows consistent with
more universally favorable support.
Schichtel
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