Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
606 PM EDT Wed Mar 26 2025
Valid 12Z Sun 30 Mar 2025 - 12Z Thu 03 Apr 2025
...North Slope high wind and blowing snow threat Sunday into
Tuesday, with snowy flow from western Alaska to the Interior...
...Guidance/Predictability Assessment...
The 12 UTC cycle guidance solutions remain quite well clustered
across and near Alaska Sunday-Tuesday. A GFS/ECMWF/UKMET/Canadian
model blend again serves as a solid and detailed forecast basis.
While the overall pattern evolution seems reasonably well defined
overall through longer time frames, increasing system timing
spread portends closer to average predictability. Opted to switch
to a blend of GEFS/ECMWF/Canadian ensemble means solutions to
maintain best WPC product continuity amid growing uncertainty.
...Weather/Hazards Highlights...
An amplified upper trough with rotating surface lows will
encompass much of the Gulf of Alaska this weekend into early next
week. Most rainfall will hold offshore, but light to terrain
enhanced moderate activity will wrap into southern/southeastern
Alaska. Expect some enhanced flow on the backside of these lows
from the eastern Aleutians and the Alaska Peninsula to the Gulf
of Alaska. Meanwhile, a strong upper ridge over the Aleutians and
Bering Sea will hold into the weekend. Modest upper troughing to
the lee of the ridge in the Interior may support some local snow.
Upstream, a dynamic upper trough set to exit eastern Asia and
developing surface low/frontal system will lift robustly
northeastward on the western periphery of the aforementioned upper
ridge and then slam through the northern portion of ridge to
impact western through northern and Interior Alaska into early
next week. This is expected to support a high wind and blowing
snow threat later Sunday into Monday/Tuesday across Northwest
Alaska and the North Slope. Flow underneath the feature into
western Alaska and the Interior is expected to support periods
with organized moderate to locally terrain enhanced snows/winds.
Additional system energies in this stream flow remain less
certain with organizational details, but still seem likely to
subsequently work within this developing system track on the heels
of the lead system through next midweek. Renewed lead upper
energies over the Interior in this pattern dig southward over the
cooling southern mainland to the Gulf of Alaska next Wednesday
and Thursday to spur additional moderate low/frontal genesis.
Schichtel
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