Alaska Extended Forecast Discussion
National Weather Service College Park MD
742 PM EDT Fri Sep 26 2025
Valid 12Z Tue 30 Sep 2025 - 12Z Sat 04 Oct 2025
...General Overview with Guidance Evaluation/Preferences...
Since yesterday, model guidance for the Alaskan domain has
switched to a synoptic pattern evolution that contains notable
differences from yesterday's model consensus. First of all, the
compact cyclone in connection with former Typhoon Neoguri is no
longer forecast to brush the Aleutians early next week but is now
forecast to pass well to the south and dissipate instead. This
scenario was first advertised by the EC-AIFS a day earlier. Other
differences of note since yesterday is a stronger Bering Sea low
midweek next week to bring precipitation farther inland across
western and southwestern Alaska. Model consensus today also shows
this Bering cyclone to have a closer link to the southern stream
flow across the North Pacific, which is also a scenario depicted
earlier by the EC-AIFS. By late next week, there is good
agreement among the ensemble means for a relatively large and deep
cyclone to move northeastward into the Bering Sea.
Farther north, models show a relatively weak upper-trough
lingering across northern Alaska, with a col remaining over the
Arctic Ocean under a stagnant synoptic pattern. No active weather
is forecast to associate with this upper trough.
The WPC forecast package for Alaska was based on a consensus blend
of 40% from the 12Z EC/00Z EC mean, 40% from the 12Z GFS/GEFS
mean, and 20% from the 12Z CMC/CMC mean, with the majority of the
blend coming from the ensemble means toward the end of the
forecast period. This blend has noticeable differences than
yesterday's WPC forecast package as discussed earlier.
...Weather/Hazards Highlights...
A round of light to moderate precipitation is forecast to spread
from northwest to southeast across western and southwestern Alaska
through midweek as a Bering Sea cyclone edges closer to the region
before sliding into the Gulf of Alaska by late next week. The
western portion of the Brooks Range can expect snow. The moderate
rainfall should progress along the southern coastline into the
Panhandle by late next week with snow possible for the Alaska
Range. By late next week, increasing winds and unsettled weather
can be expected to sweep across the Aleutians, possibly reaching
the west coast of Alaska on Friday as the large cyclone is
forecast to move into the Bering Sea.
For the remainder of Alaska, other than some snow showers the
eastern end of the North Slope early next week, benign weather is
forecast to prevail across eastern interior but the chance of
precipitation across the western and central interior has
increased due to the approach of a stronger Bering Sea low midweek.
In terms of temperatures, colder conditions will be commonplace,
with subfreezing overnight lows widespread across the Interior,
and 10s near the Brooks Range. The greater Anchorage area may have
overnight lows that approach the freezing mark early next week.
Meanwhile, near to slightly above normal temperatures are expected
for all of the southern coastline including the Aleutians and
Panhandle with lows in the 40s and highs in the 50s next week.
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