Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
659 PM EST Tue Jan 16 2024
Valid 12Z Sat Jan 20 2024 - 12Z Wed Jan 24 2024
...Guidance Evaluation/Preferences...
The 12Z/18Z model guidance suite maintains excellent agreement
with the anomalous upper level closed high over the northern
Bering for the weekend and the broad upper trough over western
Canada. However, the guidance still differs on placement of
multiple low pressure systems over the North Pacific as early as
Saturday, with the CMC west of the consensus with the upper low
that drifts west through Sunday, and this model is also
considerably stronger with the trough axis over the mainland
evolving into a closed low by Monday morning, which is not
supported by the GFS/ECMWF. Looking ahead to the middle of next
week, the CMC is slower to break down the western Bering Sea
ridge, and the ECMWF/GFS indicate a reinforcing arctic trough
settling in across the northern half of the mainland, whereas the
CMC supports more zonal flow aloft. The fronts/pressures forecast
was primarily based primarily on a GFS/ECMWF compromise with some
CMC/UKMET this weekend, and then roughly equal proportions of the
GFS/ECMWF/GEFS/ECENS for early-mid next week.
...Weather/Hazards Highlights...
A return to frigid temperatures is likely by the weekend, with the
brunt of the coldest air likely over the eastern Interior.
Overnight lows in the -20s and -30s are expected, and perhaps even
colder in the normally colder sheltered valleys. Although most of
the state should remain dry, moderate to locally heavy snow is
likely from the Kenai Peninsula to the southeast Panhandle region
for the 22nd and 23rd as Pacific moisture is advected inland.
With a strong pressure gradient in place from the strong high over
the mainland to the low pressure over the Gulf, some strong gap
winds can be expected along portions of the south-central coast
and the Panhandle for this weekend.
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