Alaska Extended Forecast Discussion
National Weather Service College Park MD
640 PM EST Thu Nov 20 2025

Valid 12Z Mon 24 Nov 2025 - 12Z Fri 28 Nov 2025

...Overview...

A blocky pattern will be in place across Alaska next week. An
upper high will track from near the Bering Strait into the Chukchi
and Beaufort Sea with ridging influence over the North Slope and
into the Mainland. Meanwhile combining upper energies west and
south of the high should create a broad mean upper low with a
surface low reflection moving slowly across the Aleutians to
Alaska Peninsula. The Aleutians low could lead to some high winds
there into Sunday, and then as it tracks eastward and weakens,
spread modest precipitation over the Alaska Peninsula and across
the southern coast. Colder temperatures are forecast next week
after an above average period in the short range.


...Guidance Evaluation and Preferences...

Model guidance is reasonably agreeable with the larger scale 
pattern described above, with the most impactful differences 
primarily regarding the details of vort maxes and resulting 
surface lows undercutting the upper high/ridge. Even at the start 
of the period Monday, model differences are seen with energy 
spilling south from Russia reaching toward preexisting troughing 
in the Aleutians. The 12Z ECMWF was particularly strong with this 
energy and yields a double barreled 500mb and surface low Monday 
into Tuesday, whereas other guidance favors energies combining 
into one low. This results in the ECMWF being farther east with 
its primary upper low into Tuesday compared to other dynamical 
models and the EC-based AIFS. The 00Z EC ensemble mean did provide
some support for this eastern position, and the 12Z EC ensemble 
mean (available after forecast generation) slowed down a touch, 
but is still faster than other guidance. The WPC forecast instead 
favored a GFS/GEFS/CMC/UKMET blend as the better clustered 
guidance that was also supported by the EC-AIFS.

For the latter half of the week, the Aleutians/AKPen low spins 
near Bristol Bay and weakens while some of its energy spills well 
south into the Pacific. The Arctic upper high is generally 
forecast to move slowly eastward with ridging atop the central to 
eastern Mainland. Meanwhile, additional upper troughing is 
forecast to eject from Japan and move through the northern Pacific
with a potentially large surface low. This looks to stay south of
the Aleutians initially, but this trough may combine with the 
lingering energy to yield troughing and surface low pressure 
influencing the Aleutians/AKPen once again. All this has fair 
agreement for a Day 6-8 forecast, so a blend of the deterministic 
models with the ensemble means was used for the latter part of the
period, favoring the means to smooth out individual model 
differences.


...Weather/Hazards Highlights...

The reasonably strong low pressure system (960s mb) near the 
Aleutians into Sunday could lead to high winds across western and 
central portions of the Aleutians, along with some precipitation. 
Into the workweek, precipitation will spread across the Alaska 
Peninsula with the primary low, while light precipitation is 
possible across the southern coast. As the low gets stalled by the
upper ridge, QPF amounts of a few inches could eventually pile up
next week over favored areas of the Alaska Peninsula, Kodiak 
Island, and the Kenai Peninsula, but likely to stay below 
hazardous levels since the precipitation falls over several days. 
Meanwhile, Interior Alaska should generally see clearer skies and 
little to no precipitation into next week as high pressure at the 
surface develops. This surface high will contrast with lower 
pressures over the Gulf, creating a pressure gradient pattern for 
possible gap winds across parts of Southcentral and Southeast and 
nearby waters. Any high winds are currently forecast to be 
localized and dependent on exact wind directions channeling 
through favored areas, so likely not widespread for any Day 3-7 
hazard area.

The surface ridge over at least eastern portions of the Interior 
will lead to cold continental flow. While temperature anomalies 
will not be too much below normal, it will be a marked change from
the relative warmth in the short range period. Highs in the 
single digits will be common with lows in the negatives. Slightly 
below average highs are possible in Southeast as well. Meanwhile 
above average temperatures could spread across the Alaska 
Peninsula into the Lower Kuskokwim and Kodiak Island given 
relatively warmer oceanic flow.


Tate


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