Alaska Extended Forecast Discussion
National Weather Service College Park MD
627 PM EST Mon Dec 8 2025

Valid 12Z Fri 12 Dec 2025 - 12Z Tue 16 Dec 2025


...Overview...

The large scale pattern over Alaska will be anchored by a mid-
upper high drifting over the Bering Sea, with height anomalies 
over 3 standard deviations above normal. On the eastern side of 
this ridge, shortwave energy is forecast to drop southward atop 
eastern portions of the Mainland late week/into the weekend and 
form troughing with a possible embedded upper low near the Gulf of
Alaska, as the eastern side of an omega block. This shortwave and
an associated frontal system should lead to some snow across the 
North Slope into the Interior particularly on Friday. Surface high
pressure across Alaska will initially block strong Pacific 
cyclones from reaching the state, keeping precipitation limited 
elsewhere. But the upper trough/low formation over the Gulf could 
lead to lower surface pressures and moisture funneling into 
Southeast Alaska for the weekend into Monday. Additionally, 
northerly flow on the backside of the Gulf low(s) could lead to 
strong gap winds for the weekend into early next week.


...Guidance Evaluation and Preferences...

Models show reasonably good agreement on the overall pattern 
described above early in the period. The upper high atop the 
southern Bering Sea Friday is forecast to drift northwest toward 
eastern Siberia over the weekend, coincident with vorticity moving
south through the eastern side. The ridge/trough interface will 
be uncertain given the differences in how far west/east the energy
drops south. A multi-model deterministic blend favoring the ECMWF
worked well as a middle ground solution though. 

By Sunday and beyond, model differences increase with the result 
of the vort max(es) feeding into the Gulf and vicinity. The 12Z 
GFS and ECMWF aligned well with each other as well as the EC-AIFS 
in producing a Gulf upper low, but the CMC was farther east into 
western Canada with this energy, which was also reflected in the 
CMC ensemble mean. Leaned away from the lower probability CMC-type
solutions at this point. Within the generally favorable pattern 
for surface lows to form underneath the upper trough/low in the 
Gulf, there is considerable spread in the details. The 12Z ECMWF 
seemed stronger than preferred by early next week as it took a 
surface low in the 950s mb toward Southeast Alaska. The details of
these lows will affect sensible weather like the direction and 
strength of gap winds. The eventual evolution of upper energy will
be dependent on the track of an Arctic upper low north of the 
state, which is also uncertain. Thus for now, the WPC forecast 
gradually increased the proportion of ensemble means to over half 
Days 7-8 given the increasing spread.


...Weather/Hazards Highlights...

A round of light to moderate snow is likely for the North Slope, 
Brooks Range, and Interior late this week as shortwave energy 
passes over. Then as the shortwave develops into an upper low in 
the Gulf, the lowering heights will allow for surface pressures to
decrease closer to the southern coast of Alaska. Mean low 
pressure for the Gulf over the weekend and into early next week 
should lead to moist southwesterly flow into Southeast for some 
precipitation. The cold temperatures in place will mean most of 
this precipitation falls as snow, and moderate snow totals are 
likely on Sunday and Monday especially. Behind the mean surface 
low, strong gap winds are possible given the tight pressure 
gradient. While the details are uncertain, the pattern for 
northerly gap winds will be favorable across the Alaska Peninsula 
toward Cook Inlet. Outflow winds are also possible for portions of
Southeast Alaska in the Yakutat vicinity. High winds areas are in
place on the Day 3-7 Hazards product.

Temperatures will continue to be bitterly cold in the eastern 
Mainland into Friday morning, with lows in the -30s in areas like 
the Yukon Flats. Meanwhile milder than average temperatures are 
likely across the western Mainland and North Slope underneath the 
upper high, with near to slightly above average temperatures 
reaching across the Interior Friday and Saturday. But as the upper
ridge edges westward and troughing returns to the south-central 
part of the state, colder temperatures will return by early next 
week, with widespread anomalies 20-40 degrees below normal. 
Fairbanks is expected to see another few days of temperatures 
staying well below 0F, while single digit highs are possible in 
Anchorage. Colder than average temperatures are likely across 
Southeast Alaska as well, though the southern parts of the 
Panhandle should see increasing temperatures as the period 
progresses due to the relatively warmer moist inflow. Meanwhile 
the North Slope looks to stay above normal most days, though the 
anomalies should not be as high as the late week period.


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