Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
607 PM EST Tue Jan 30 2024
Valid 12Z Sat Feb 03 2024 - 12Z Wed Feb 07 2024
...Bitterly cold temperatures to linger over the Interior into
late week...
...Overview...
Deep upper troughing and embedded closed low over Alaska should
shift east into northwest Canada by the weekend as upper ridging
builds in upstream and shifts over the Mainland. This should help
moderate bitterly cold temperatures across the state as well as
usher in a drier overall pattern for much of the Interior and the
Southeast. A deep upper low will affect much of the Aleutians late
this week with increased precipitation and gusty winds before
rotating north/westward and becoming absorbed into an additional
upper low dropping down from the Kamchatka Peninsula. Multiple
streams of energy rotating around the base of this broad trough
will keep conditions unsettled across the Aleutians and more
moderately into Southwest Alaska through the Alaska Peninsula,
then eventually the Southern Coast.
...Guidance Evaluation/Preferences...
The 12 UTC GFS/ECMWF solutions seem best clustered with
GEFS/ECMWF/Canadian ensemble means over medium range time scales.
Prefer to gradually increase blend influence from these models to
the ensemble means over time, consistent with forecast spread
growth. This plan maintains good WPC product continuity in a
transitional pattern with seemingly near average overall
predictability.
...Weather/Hazards Highlights...
A deep surface low near the Aleutians into Saturday should support
increasing precipitation from west to east as the cold front
shifts through the Aleutians. Also likely to be a period of gusty
high winds given the strong pressure gradient present. Additional
surface lows into early next week will continue to keep unsettled
conditions across the Aleutians and farther east towards
Southwestern Alaska with wrapping flow, then downstream for the
Southern Coast of Alaska. This will be fueled by general moist
southerly flow as system energies/triple point lows split
underneath the state into the northern Gulf of Alaska, with some
modest periodic activity with weakened systems working toward the
Southeast.
Well below normal temperatures over the Mainland will linger
through the end of the week (some locally colder than -50F over
colder spots of the eastern Interior), but should continue to
steadily ease heading into the weekend. After this, a general warm
up will be in place as upper ridging builds over the state, but
parts of the eastern Interior may hold onto the below normal temps
even into early next week. By next Monday-Tuesday, the greatest
positive anomalies should be across western Alaska and the North
Slope along with parts of Southwest Alaska, where daytime highs
could be 10-20+ degrees above normal, a strong contrast to
conditions currently. Southeast Alaska looks to stay near or below
normal most of the forecast period.
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