Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
722 PM EDT Fri Mar 22 2024
Valid 12Z Tue Mar 26 2024 - 12Z Sat Mar 30 2024
...Deep Pacific Storm may Threaten Alaska late next week...
...Guidance Evaluation and Preferences...
Run to run guidance continuity from short range to medium range
time periods for the Bering Sea and the Mainland have been quite
less than stellar with digging Arctic stream systems, but seems
better with more energetic/stormy Pacific flow to impact the
state. Despite apparent initialization sensitivities, 12 UTC
GFS/ECMWF and GEFS/ECMWF ensemble mean solutions seem surprisingly
well clustered across the domain for much of next week and a
composite was utilized to produce the WPC Alaskan medium range
product suite. While forecast confidence at higher latitudes is
tempered given recent issues, it is comforting that the
â€correction†for this cycle is manifested in the short range
when changes of this order can often be considered reliable.
...Pattern Overview and Weather/Hazards Highlights...
Leading Pacific/Gulf of Alaska system energies and moisture will
act to focus lingering wet conditions from the Alaska Peninsula
and Kodiak Island through SouthCentral and more modestly into the
Southeast Tuesday before losing influence. Coastal rains and
inland/terrain snows seem generally light to moderate.
Meanwhile, guidance has trending strongly toward the weekend
digging of much more defined Arctic stream upper trough energy
down into the Bering Sea to the lee of initially amplified upper
high/ridging upstream. This closed low should meander and slower
weaken over the Bering Sea into mid-later next week. This pattern
may favor enhanced/high winds offshore from the Bering Strait to
the Bering Sea and offer light to moderate western/southwestern
mainland snow potential as aided by any uncertain
interaction/lifting moisture from southern stream energies.
Later, there is quite an emerging guidance signal to monitor for
subsequent development and approach of amplified closed upper
trough/low Pacific stream energy and associated deep surface low
pressure system toward the Aleutians by later next week that would
offer turbulent maritime conditions and swirling winds and rains.
This potentially potent storm may work northeastward to mainland
Alaska into next weekend with some punch.
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