Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
454 PM EST Mon Feb 19 2024
Valid 12Z Fri Feb 23 2024 - 12Z Tue Feb 27 2024
...Stormy Pattern Continues for Alaska...
...Guidance Evaluation and Preferences...
The 12 UTC GFS/ECMWF/UKMET/Canadian model solutions are overall
well clustered into next weekend in active flow and have good
ensemble support. A favored composite offers maximum system detail
consistent with a pattern with seemingly above normal
predictability and improving run to run consistency. Added into
the blend input from the ECMWF ensemble mean into next week amid
growing forecast spread. This ensemble mean seems best compatible
with the models at these longer time frames. WPC product
continuity is reasonably well maintained, but system timings will
remain an issue with such strong upper jet flow.
...Pattern Overview and Weather/Hazards Highlights...
Expect an increasing dynamic flow pattern as a powerhouse east
Asian upper jet punches eastward across the northern Pacific
toward Alaska around the base of an amplified Bering Sea mean
upper low/trough position. In this pattern, expect protracted
gusty winds through the Aleutians. Energy/height falls with the
upper trough are expected to work through the Bering Sea and
toward the mainland. Unsettled conditions with inland working
systems will include some locally enhanced winds and periods of
light to moderate snow up through Southwest and over a cooling
North Slope/Interior with downstream translation. Cooling may be
significantly enhanced into early next week with less certain
digging/intrusion of unsettling Arctic stream energy down through
the mainland.
Meanwhile underneath, the potent upper jet and embedded upper
trough system energies will slam eastward to the Gulf of Alaska,
spreading a threat for high winds. This and associated surface
based system development and track of a series of organized lows
to the south of the Aleutians and across the Gulf will
periodically enhance precipitation from the Alaska
Peninsula/Kodiak Island through SouthCentral and Southeast Alaska
into late week/weekend as fueled by long fetch moisture, with
greater uncertainty into next week to monitor and update.
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