Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
656 PM EST Wed Jan 27 2021
Valid 12Z Sun Jan 31 2021 - 12Z Thu Feb 04 2021
...Overview and Guidance/Uncertainty Assessment...
An upper level ridge that will initially be in place across
western Alaska and the eastern Bering Sea on Sunday will gradually
progress eastward and be over the Gulf of Alaska region by
Tuesday/Wednesday. By the end of the forecast period, a rather
pronounced upper level trough becomes established over the western
Aleutians with some lead shortwave energy lifting northeastward
ahead of it.
The WPC Alaskan medium range product suite was derived from
reasonably well clustered guidance from the 12 UTC GFS and ECMWF
models for Sunday through Tuesday, along with the 19 UTC National
Blend of Models and some of the ensemble means. For next
Wednesday and Thursday, there was a gradual increase in using the
GEFS/ECMWF ensemble means due to increasing deterministic model
spread.
...Weather/Hazards Highlights...
The next storm approaching from the western Aleutians early next
week is expected to produce moderate precipitation and gusty winds
across the Aleutians through Tuesday, and then likely reaching the
southern mainland by the middle of next week. It appears that the
moisture plume will be progressive enough to keep things from
getting too heavy or persistent. For the Interior region, most of
the forecast period should be dry and cold with perhaps a few
light snow showers.
Hamrick
Hazards:
No significant hazards are expected over Alaska during this
forecast period.
Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards 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