Alaska Extended Forecast Discussion
National Weather Service College Park MD
502 PM EST Tue Nov 18 2025

Valid 12Z Sat 22 Nov 2025 - 12Z Wed 26 Nov 2025

...Synoptic Overview...

On Saturday, broad surface troughing across the state from a dying
low will remain in place through much of the period. This is due
to the development of a blocking pattern in the upper levels. An
omega block will set up across the state by Sunday, which will
likely become undercut by its western side low over the Aleutians,
forcing the ridging north, thus becoming a rex block. The blocks,
regardless of form, will prevent any very strong storms from
impacting much of the mainland, which will be under the ridging,
or the far weaker Gulf low on the east side of the omega block.
Meanwhile all the truly active weather will remain out over the
Bering, as strong lows track nearly due north, unable to progress
east due to the blocks. Once the pattern transitions to more of a
rex block by Tuesday, most of the Pacific storms will track to the
east, south of the Alaska Peninsula, thus keeping most of mainland
Alaska quiet.

...Guidance Evaluation and Preferences...

A 12Z GFS/ 00Z EC blend was used as the predominant deterministic
guidance for the forecast through the weekend, transitioning to a
primarily GEFS blend through midweek. The 12Z GFS and 00Z EC were
best in line with each other compared to the other guidance,
especially into the upcoming workweek. This pattern favors the
strong Pacific low over the Bering occluding quickly by Monday
with perhaps numerous weak triple point lows developing along it
across the Alaska Peninsula and south of the Gulf. Meanwhile, much
of the other guidance was significantly off from both this
solution and the others, or were major outliers, such as the 12Z
EC.

...Weather/Hazards Highlights...

The primary hazard impacting the state will be across the western
and central Aleutians this weekend. As a Pacific low tracks north,
it will rapidly deepen. This deepening low will contrast to the
broad ridging across the eastern Bering and western mainland,
resulting in a rather narrow (100 mile wide or so) corridor of
strong southerly flow. Gusts to 55 kt are probable in this area,
especially Saturday night. Fortunately the low and its front
rapidly weaken beyond that, ending that threat. With the big low
staying well out into the western Bering, no hazardous or
otherwise noteworthy synoptic scale weather is expected elsewhere
through Wednesday.

&&

Wegman



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