Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
656 PM EST Sat Feb 6 2021
Valid 12Z Wed Feb 10 2021 - 12Z Sun Feb 14 2021
...Overview and Guidance/Uncertainty Assessment...
A deep upper level low is expected to be in place across northern
Alaska at the beginning of the forecast period on Wednesday. With
this low lifting northwest over the Arctic Ocean by the end of the
week, a ridge axis is expected to build in over the state.
Meanwhile, a stormy weather pattern appears likely across the
southern Bering Sea and the Aleutians as a couple of Pacific storm
systems pass through that region. The mega surface high north of
the Arctic Coast (models suggest greater than 1065 mb!) is
forecast to remain well north of the state for this time period.
The model guidance has come into better synoptic scale agreement
compared to yesterday, with the greatest model differences related
to the evolution of the mid-upper level ridge over the mainland.
There was a slightly greater weighting towards the 12Z ECMWF/00Z
EC mean as a starting point in the forecast process, along with
some of the 12Z GFS/CMC.
...Weather/Hazards Highlights...
Frigid temperatures are expected to be in place across much of the
central and northern portions of the state through Friday, with
widespread 25-50 below readings expected for overnight lows,
particularly in sheltered valleys. There should be a gradual
moderating trend by next weekend as the upper level ridge builds
in and slowly erodes the extreme cold. Periods of rain and snow
are likely across the Aleutians and the southeast Panhandle
region, but nothing particularly heavy is currently anticipated.
Hamrick
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
Hazards:
- Much below normal temperatures across portions of mainland
Alaska, Sun-Thu, Feb 9-Feb 11.
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