Alaska Extended Forecast Discussion
National Weather Service College Park MD
739 PM EDT Wed Oct 29 2025

Valid 12Z Sun 02 Nov 2025 - 12Z Thu 06 Nov 2025


...Synoptic Overview...

The synoptic pattern across the Alaskan domain continues to favor
fast-moving cyclones to track west to east through the Aleutians 
then gradually dissipate over the Gulf of Alaska as a negatively- 
tilted upper ridge remains stationary across eastern mainland 
Alaska and further up into the Arctic Ocean in the form of an 
omega block.


...Guidance Evaluation and Preferences...

The ensemble means from the ECMWF, GEFS, and CMC show decent 
agreement on the above-mentioned synoptic pattern evolution 
through the medium-range period. Much of the uncertainty is
in regard to the timing of a couple of cyclones that are forecast
to reach and move from west to east along the Aleutians early 
next week. The GFS is near the slow end of the spectrum followed 
by the UKmet, while the ECMWF and CMC are near the fast end of the
spectrum regarding both of these cyclones by a few hundred miles 
to the east. The GFS has trended toward the faster EC/CMC solution 
since yesterday regarding the leading cyclone forecast to move 
swiftly across the Aleutians Sunday night into early Monday. By 
the end of the medium-range period, both the deterministic and 
ensemble means show decent agreement on the next significant 
cyclone to track along the Aleutians with the GFS/GEFS cluster 
placing the cyclone center brushing just south of the island 
chain while the EC/CMC cluster remains farther south and with a 
much faster forward motion.

The Alaska forecast package was based on a general model consensus
of 40% from the 12Z ECMWF/00Z EC mean, 40% from the 12Z GFS/GEFS, 
and 20% from the 12Z CMC/CMC mean, with the majority of the blend
based on the consensus of the ensemble means for Days 6 to 8 and
leaning toward the faster EC/CMC cluster. This blend yielded an 
isobaric pattern compatible with yesterday's WPC forecasts but
with a slower eastward progression and farther separation of the 
cyclones traveling south of the Aleutians into the Gulf of 
Alaska.


...Weather/Hazards Highlights...

The medium-range period will begin with the weakening phase of a 
deep cyclone centered over the Gulf of Alaska, along with the 
moderate to locally heavy precipitation gradually tapering off 
through the end of the weekend across South Central to the 
Panhandle. Nevertheless, light to locally moderate precipitation 
is forecast to linger along the southern shoreline to the 
Panhandle through midweek.

Thereafter, a couple of cyclones appear to track very quickly
near/along the Aleutians early to middle of next week, with the
subsequent cyclone being the stronger of the two. Unsettled
weather appears to be in store for the Aleutians by early next
week before reaching the Peninsula possibly by midweek. The
predicted pressure pattern appears to favor high winds behind 
this system. Therefore, a "High Winds" area has been introduced 
on the WPC Hazards Outlook map for the central to eastern 
Aleutians on Day 7 Wednesday 11/5.

Temperatures will be mostly above average except for the central  
Brooks Range, and along the eastern Aleutians this weekend when
below normal high temperatures are in the forecasts. Gradual 
clearing skies will allow temperatures to return closer to normal
for interior mainland Alaska while clouds and precipitation will
keep high temperatures cooler than normal across the West
Southwest.


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