Alaska Extended Forecast Discussion
National Weather Service College Park MD
753 PM EDT Sun Sep 27 2026

Valid 12Z Thu 1 Oct 2026 - 12Z Mon 5 Oct 2026

...General Overview...

The weather pattern remains active over the North Pacific and into
the Gulf with a well organized storm system tracking just south
of the Aleutians and then into the Gulf by the end of this week,
followed by another storm system across the Bering next weekend. A
broad upper trough with embedded closed low will be in place
across the northern half of the state, and surface high pressure
moves from the northern Bering to western Alaska by Saturday.

...Guidance Evaluation and Preferences...

The 12Z model guidance suite features decent overall agreement
across the Alaska domain for the beginning of the forecast period
Thursday, with a multi-deterministic model blend used for fronts
and pressures. Modest differences emerge across the north Pacific
and Gulf by Friday as the next storm system arrives, and then
model and ensemble spread becomes more substantial regarding
mesoscale details on the Gulf system towards next weekend, with
ensemble means increased to about 40 to 50% by that time.

...Weather/Hazards Highlights...

The next cyclone on the horizon should cross just south of the
central Aleutians by Thursday, and will likely enter the Gulf by
late Friday and into the weekend. There will likely be gale force
winds across the Aleutians with a period of enhanced rainfall as
it tracks through the Aleutians. By next weekend, the South-
central part of the state should begin to see an atmospheric river
ahead of the main low, with a few inches of rainfall likely
between the Prince William Sound and Sitka. Meanwhile, the rest
of mainland Alaska up through the Brooks Range and North Slope
should remain mostly dry with a few showers at times, and
temperatures overall should be slightly below late September
averages across much of the Interior.

In terms of hazards, the expected rainfall across southeast
Alaska is close to needing a heavy rainfall area, but it does not
appear that rainfall rates and 24-hour totals are quite high
enough at this time. This will continue to be monitored in the
days ahead.

Hamrick


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