Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
657 PM EST Wed Feb 03 2021
Valid 12Z Sun Feb 07 2021 - 12Z Thu Feb 11 2021
...Overview and Guidance/Uncertainty Assessment...
An upper level low that is expected to initially be over far
northwestern Canada on Sunday is expected to slowly settle in over
central and northern Alaska by the middle to end of next week.
Meanwhile, a narrow ridge axis will likely exist across the
Aleutians and Bering Sea region. Surface low pressure is expected
to persist over the norther Gulf of Alaska with multiple
shortwaves pivoting around the main upper low over the mainland.
The 12Z CMC take the upper low farther south across the Interior
region, whilst the 18Z GFS/GEFS mean keep the low just north of
the Arctic Coast.
...Weather/Hazards Highlights...
Persistent low pressure over the Gulf of Alaska will tend to focus
periods of precipitation over the southeastern coast and Panhandle
through the period. A leading wave arriving by the start of the
weekend should provide the initial push of moisture with moderate
totals expected. After the weekend there is increasing
uncertainty over precipitation intensity over this area, depending
on specifics of the upper low/trough that may move into the
mainland. Current guidance preferences would yield light-moderate
activity most of the time but an upper flow orientation that could
bring greater moisture into the region is a lower-probability but
possible scenario. One or more features lifting up the western
side of upper ridging may support episodes of precipitation/brisk
winds over portions of the Aleutians and southwestern half of the
Bering Sea. The weekend will start with above normal temperatures
over southern/western areas and below normal readings to the
north/east. Then a colder trend from north to south will likely
yield below to well below normal readings over much of the state
during the first half of next week.
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, Mon-Tue, Feb 8-Feb 9.
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