Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
608 PM EDT Wed Nov 3 2021
Valid 12Z Sun Nov 7 2021 - 12Z Thu Nov 11 2021
...Overview and Model Guidance...
A large upper level gyre is expected to be in place across the
Gulf of Alaska this weekend along with a upper ridge axis over the
Aleutians and the Bering Sea. By Tuesday, more shortwaves track
south of the Aleutians and south of the Bering/western Alaska
ridge, and this should evolve into a broad upper trough over
western Alaska and the Gulf region by the middle to end of next
week with upper level ridging returning to the western Aleutians.
The 12Z deterministic guidance is in relatively good agreement on
the synoptic scale this weekend and have a good depiction of the
Gulf upper level gyre. This includes the CMC which has trended
much closer to the model consensus compared to yesterday. The
UKMET is displaced some to the northwest by Monday night with that
same upper low and becomes less favored in the forecast blend. By
the end of the forecast period, the CMC has a stronger shortwave
crossing the Bering whereas the ensemble means are suggesting a
well developed ridge across this region, so less of it was applied
for days 7 and 8.
...Weather/Hazard Highlights...
Overall, the Alaska region should be relatively quiet in terms of
impactful precipitation events with most of the mainland staying
dry, except for some isolated snow showers. The Aleutians could
be the exception since this region would be closer to the storm
track over the North Pacific, but nothing appears to be excessive
at this time. In terms of temperatures, readings are likely to be
slightly above average across much of the central and northern
portions of the state through early next week, before
transitioning to a colder pattern across the western half of the
state as the upper level trough becomes more established across
the region.
Hamrick
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