Alaska Extended Forecast Discussion
National Weather Service College Park MD
738 PM EDT Sat Oct 11 2025
Valid 12Z Wed 15 Oct 2025 - 12Z Sun 19 Oct 2025
...Active pattern continues to bring high winds across the
Aleutians to western mainland Alaska while heavy precipitation is
expected for the southern coastal areas...
...Guidance Evaluation and Preferences...
Model guidance continues to depict an active synoptic pattern
that brings fast-moving and deep cyclones across the Aleutians
toward western or southwestern Alaska through the medium-range
period. Regarding the next cyclone of concern through midweek next
week, the deterministic guidance yesterday had shown a southward
trend in the cyclone track. Today's deterministic guidance shows a
mixed signal, however. The ECMWF continues the southward trend to
track the cyclone center now entirely south of the Aleutian
Islands on the 12Z run. Meanwhile, today's earlier GFS runs had
shifted to a comparable southern track before switching back to a
track across Bristol Bay Wednesday morning. This intermediate
track is what has been advertised today by the consensus of the
ensemble means (which is also farther south than yesterday's). On
the other hand, the EC-AIFS has been consistently near the
southern end of the guidance envelop.
By late next week, despite increasing spread with the
deterministic model outputs, ensemble means from dynamical models
show fairly good agreement for the next occluded cyclone to
quickly reach the Aleutians and then move into the Bering Sea.
Although this cyclone appears less intense than its predecessor,
the eastern extension of the cyclone is forecast to carry abundant
moisture across the southern coastal areas to the northern end of
the Panhandle later next week. The main cyclone itself is
forecast to weaken while edging toward western Alaska late next
week. Meanwhile, an occluded cyclone originated from tropical
cyclone Nakri is forecast to pass a fair distance south of the
Aleutians.
By next weekend, the deterministic guidance including the EC-AIFS
begins to indicate a rather strong cyclone to possibly reach the
Aleutians. The ensemble means are much less robust in the cyclone
intensity but show good agreement on its placement.
The WPC forecast package for Alaska was based on the consensus of
40% from the 12Z ECMWF/00Z and 12Z EC mean, 40% from the 12Z
GFS/GEFS, and 20% from the 12Z CMC/CMC mean, with Days 7 and 8
mainly the consensus of the ensemble means. This blend yielded the
midweek cyclone track farther south than yesterday's forecast
package.
...Weather/Hazards Highlights...
Impacts from the next deep cyclone of concern will likely make
its presence felt beginning on Tuesday across the Aleutians with
cyclonic winds possibly approaching storm-force on some of the
islands if the cyclone center ends up tracking to their north,
along with moderate rainfall. The high wind threat and moderate
precipitation should overspread much of the Southwest and the
Alaska Peninsula on Wednesday as the core of the cyclone makes
landfall over southwestern mainland. The high wind threat should
gradually lessen across western Alaska later next week but triple-
point wave development over the Gulf of Alaska will likely bring
heavy precipitation from South Central to northern Panhandle for
the latter half of next week. In addition to the heavy
precipitation, a high wind threat is forecast to extend eastward
into the South Central region on Wednesday before the triple-point
wave gradually weakens late next week. By next weekend, the
threat of high winds appears increasing across the Aleutians
given the latest model indications on what could be the arrival of
the next deep cyclone.
Temperature-wise, persistent southwesterly flow across the Alaska
domain will keep temperatures above normal for much of the state
through the medium-range forecast period.
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