Alaska Extended Forecast Discussion
National Weather Service College Park MD
650 PM EST Sat Dec 6 2025

Valid 12Z Wed 10 Dec 2025 - 12Z Sun 14 Dec 2025


...Overview...

The synoptic-scale upper pattern across Alaska from midweek next
week to next weekend will likely feature an amplifying omega block
with an increasingly pronounced warm core high anchoring over the
Bering Sea. Meanwhile, an arctic surface high will remain lodged
against the Alaska Range under the eastern branch of the omega
block sustained by upper-level convergence. This pattern will
effectively prevent strong Pacific cyclones from reaching the 
Alaska domain. Only a relatively weak system manages to approach 
the southern portion of the Alaska Panhandle by next weekend.


...Guidance Evaluation and Preferences...

The ensemble means from major global models are in favor of the
above-mentioned synoptic scale pattern through next weekend. The 
high amplitude and strength of the omega blocking pattern will 
effectively keep strong cyclones from reaching the Alaska domain. 
Nevertheless, the Canadian model has been allowing a fairly strong
low pressure/frontal system to sneak across the northern 
periphery of the omega block by next Friday or so over the Arctic 
Ocean. This scenario was only weakly supported by other models as
well as the 00Z EC ensemble mean. However, the 12Z EC ensemble 
mean appears much more supportive of this scenario.

The WPC medium-range forecasts for Alaska was based on the
consensus blend of 40% from the 12Z GFS/GEFS, 40% from the 12Z
ECMWF/00Z EC mean, and 20% from the 12Z CMC/CMC mean. This blend
yielded a solution fairly compatible with yesterday's forecasts
with notable differences across the Arctic Ocean and the 
northeastern Pacific.


...Weather/Hazards Highlights...

With the omega block over the Bering Sea forecast to amplify
further through the medium-range period, there is not a 
substantial low pressure system to speak of that will get close to
the Alaska domain. Nevertheless, there remains the possibility of
northerly gap winds across eastern Aleutians to the Alaska 
Peninsula and into the waters near Kodiak Island and the western 
tip of the Kenai Peninsula on Tuesday between the building high 
over the Bering Sea and a surface low that is forecast to track 
well to the south. Farther north, light snow ahead of a frontal 
system and the possibility of a low pressure system passing north 
of Alaska is forecast to reach at least the western portion of the
Brooks Range and the North Slope late next week into the weekend.
Other than that, an arctic surface high is forecast to remain 
anchored across mainland Alaska to keep it frigid and dry south 
of the Brooks Range. Temperatures down into the -30s will be 
common across interior Alaska, with the coldest readings into 40 
below zero early to midweek next week for the Yukon Flats and 
near the Canadian border in eastern interior section. A Hazardous 
Cold area has been introduced for the eastern interior section for
Dec 9-10. In contrast, temperatures will remain as much as 20 
degrees milder than normal for the North Slope and western portion
of Seward Peninsula. The Aleutians will also be somewhat milder 
than normal through the medium-range period.

Across the Alaska Panhandle, light precipitation associated with a
dissipating cyclone near the start of the medium-range period 
should taper off further. But precipitation chances will likely 
increase gradually through late next week and into the weekend, 
especially for the southern half of the Panhandle, as a relatively
weak low/wave approaches slowly from the Pacific.

Kong


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