Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
401 PM EST Thu Jan 28 2021
Valid 12Z Mon Feb 01 2021 - 12Z Fri Feb 05 2021
...Overview and Guidance/Uncertainty Assessment...
An upper level ridge that will initially be in place across
western Alaska and the western Gulf of Alaska on Monday will
gradually be suppressed over the northeastern Pacific by the
middle of the week. By the end of the forecast period, a rather
pronounced upper level trough and large surface low becomes
established over the western Aleutians/western Bering with some
lead shortwave energy lifting northeastward ahead of it.
The WPC Alaskan medium range product suite was primarily derived
from the 12Z CMC/00Z ECMWF with some of their respective means as
a starting point in the forecast for fronts and pressures, and
slightly less weighting towards the 12Z GFS since it was a bit
more progressive with the surface low crossing the northern Gulf
region compared to the other guidance. For next Thursday and
Friday, there was a gradual increase in using the CMCE/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 evening, and then likely
reaching the southern mainland by the middle of next week as the
low emerges over the northern Gulf. It appears that the moisture
plume will be progressive enough to keep things from getting too
heavy or persistent. For the Interior region and the northern
tier, most of the forecast period should be dry and frigid with
perhaps a few light snow showers. Overall temperatures are
expected to be below normal for much of the forecast period, with
some minus 40 degree readings likely for the normally colder
locations! Another round of precipitation may affect the
Aleutians and southwestern Alaska by the end of the week as the
next storm system approaches the region.
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