Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
527 PM EST Sun Mar 06 2022
Valid 12Z Thu Mar 10 2022 - 12Z Mon Mar 14 2022
...Overview...
A persistent upper high atop eastern Russia and the Chukchi Sea
will help promote above normal temperatures for portions of
northern and eastern Alaska through next Monday. Mainland Alaska
will generally be in a col pattern between this feature, rounds of
upper troughing/lows over the Aleutians, ridging over the East
Pacific that should get shunted eastward by late week, and periods
of troughing in the northeastern part of the state. This should
lead to unsettled weather particularly over the Aleutians, with
some precipitation spreading east in the southern half of the
mainland and Panhandle.
...Guidance/Predictability Assessment...
The latest guidance continues to have a decent handle on the upper
high that will be positioned to the northwest of the state/eastern
Russia with high pressure also over the eastern Pacific ocean.
This would favor general troughing near the northeast part of the
state as well as an active gyre over the Bering Sea/Aleutian
region. There was been run-to-run variability with the series of
lows expected to rotate through the Aleutians/adjacent region and
across Northeast Mainland. The details of these smaller scale
features within this broader troughing pattern are quite uncertain
and will likely take a few more days for models to converge
properly. Regardless, models generally show some of this energy
spilling eastward to shunt the East Pacific ridge east into North
America by late week, though with some timing differences. The WPC
forecast mostly comprised of a combination of the 12Z
ECWMF/GFS/UKMET for the first few periods before transitioning to
a blend of the ECWMF/EC ensemble means/GFS/GEFS Mean for the later
periods. This weighting provided a since of continuity from the
previous forecast cycle.
...Weather/Hazard Highlights...
Much of the region will be unsettled as a series of surface lows
(including triple point lows) will rotate/reform near the
Aleutians within a broader trough. These features will allow for
periods where there are enhanced winds and rainfall, primarily for
the the Aleutian Chain but modest precipitation will also spread
eastward along the southern tier of the Mainland and parts over
the Southeast. The heaviest amounts are forecast along the coast,
but some snow should spread farther north in the mainland as well.
A large portion of the Mainland will be mild and mostly dry. Daily
temperatures, particularly in terms of overnight/morning low
readings that are forecast to range 15 to 30F warmer than seasonal
average, while the afternoon highs range 10 to 20F warmer than for
locations across northern and western Alaska. The Panhandle and
the eastern part of the Mainland will generally be cooler during
the extended period. In general, temperatures should moderate
closer to normal by next weekend but remain above average for
western Alaska, while the Panhandle and eastern mainland are
cooler.
Campbell/Tate
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