Alaska Extended Forecast Discussion
National Weather Service College Park MD
637 PM EDT Sun Aug 10 2025
Valid 12Z Thu 14 Aug 2025 - 12Z Mon 18 Aug 2025
...General Overview...
The pattern over Alaska should be quiet and stagnant by late week
and especially next weekend as amplified ridges over the Bering
Sea and central Canada keep troughing over the Alaska Mainland and
into the Gulf. Low pressure meandering in the Gulf will keep
shower chances along the Panhandle most days, with the heaviest
rainfall expected Thursday-Friday as a frontal system weakens in
the region. Across northern Alaska, weak shortwaves will rotate
through the base of a deep low over the Arctic.
...Guidance Evaluation/Preferences...
The current model and ensemble guidance continues to show
excellent agreement on the large scale blocky and slow moving
pattern over Alaska during the extended range. There are some
differences in the details of individual weak shortwaves, some of
which do not have much impact on sensible weather across the
state. The most notable outlier was the UKMET which showed a
stronger initial shortwave and surface low into the Gulf early
period. The WPC forecast today used a blend of the ECMWF and
GFS/CMC through about the first half of the period, increasing to
about 60 percent ensemble means days 7 and 8 to help smooth out
the smaller scale differences.
...Weather/Hazards Highlights...
Rainfall will be ongoing by Thursday over the Mainland to
Southern Coast area associated with a shortwave moving through the
state. Moderate to locally heavy rain may be possible along the
favored terrain. Conditions should mostly dry out by Friday and
into the weekend, but some showers are possible as weak shortwaves
rotate through northern Alaska. To the South, moderate rain over
the Panhandle will accompany a cold front as it moves through the
Gulf late this week, with rain becoming more widely scattered in
nature by the weekend and into early next week. Temperature wise,
conditions should be near to slightly below average by the end of
the week into next weekend across much of the mainland, and near
average for the most part for the southern coastal areas.
Santorelli
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