Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
342 PM EST Wed Nov 20 2024
Valid 12Z Sun Nov 24 2024 - 12Z Thu Nov 28 2024
...A shot of snow expected for western and central Alaska this
weekend...
...Enhanced gap winds for a cooled Southeast Alaska mid
next-week...
...Guidance Evaluation/Preferences...
The guidance has come into better agreement with a potentially
impactful low moving by the Bering Strait this weekend. The big
outlier overall was the 12z Canadian, which became out of phase
with the other guidance early next week in and near the Bering
Sea. When the guidance was most agreeable, used a composite 12z
GFS/ECMWF/UKMET/Canadian model blend early on before including
more strongly towards the 12z NAEFS/ECMWF ensemble means with
time. Most of the grids are 19z NBM weighted, as usual, though
went without including the 12z Canadian due to its outlier status
next week. The QPF was equal parts ECMWF/GFS and NBM.
...Weather/Hazards Highlights...
A shot of moderate to heavy snow is expected in western and
central Alaska this weekend as a cyclone moves by. This system
should bring gale-force winds near the Bering Strait. A warm core
high should increasingly shield southern AK from much cooling or
significant precipitation. As is typical, the coldest readings
will be on the North Slope and eastern interior, though the
eastern interior will see fluctuations due to the frontal passage.
In the wake of the front, gap winds should strengthen/renew near
the AK Panhandle early to mid next week. With the guidance
backing off on cyclone(s) approaching the Aleutians, there has
been a decided lowering in expected precipitation for the entire
state of Alaska when compared to the past couple days of
continuity.
Roth
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