Alaska Extended Forecast Discussion
National Weather Service College Park MD
746 PM EDT Fri Jul 25 2025
Valid 12Z Tue 29 Jul 2025 - 12Z Sat 02 Aug 2025
...Overview...
Much of mainland Alaska through the medium-range period next week
appears to be sandwiched between a nearly stationary closed low
over the Gulf of Alaska and a shortwave trough moving through
northern mainland and lifting into the Arctic Ocean. Meanwhile,
the ridge initially crossing the Aleutians into the Bering Sea is
forecast to de-amplify with time as the next low pressure system
should be sliding east into the Aleutians toward the end of next
week.
...Guidance Evaluation/Preferences...
The latest guidance remains well-clustered with the Gulf of
Alaska low being nearly stationary or moves ever so slightly
toward the southern coastline by the end of next week. Meanwhile,
model guidance shows a good signal for the next significant
cyclone and frontal system to reach the western portion of the
Aleutians late next week but with a considerable amount of spread
along a southwest to northeasterly direction. The ECMWF solutions
are the quickest in comparison with the GFS and CMC regarding
that system. The EC-AI adopts an even faster and more amplified
solution.
Elsewhere, there is noticeable spread in the deterministic
guidance to the north of Alaska regarding the potential
amplification of a frontal wave. However, ensemble means indicate
a non-developing stationary front will remain draping across
northern Alaskan mainland.
The WPC forecast guidance leans toward the faster ECMWF solutions,
with the majority of the forecast blend coming from the ensemble
means toward the end of the forecast period. This approach
maintains good continuity from the previous forecast.
...Weather/Hazards Highlights...
Much of the precipitation across mainland Alaska for next week
will likely be associated with the shortwave trough moving across
northern Alaska where moderate rainfall can be expected along the
Brooks Range through midweek. Occasional moderate rainfall can
also be expected along the Alaska Range on the outer edge of the
slow-moving cyclone in the Gulf of Alaska. While these rains may
persist for a while, they are not expected to be heavy. Some wet
snow may mix in at the highest elevations. Only occasional light
rain is expected for portions of the southern coastline into the
Panhandle.
From midweek onward, a round of more appreciable rainfall is
forecast to gradually overspread the Aleutians through the
medium-range period. The associated low pressure system is
forecast to move slowly east along the Aleutians but may amplify
and move faster in advance as suggested by the EC-AI.
Daily high temperatures are expected to remain below normal
Tuesday and Wednesday across much of mainland Alaska with the
passage of the shortwave trough along with clouds and rainfall. A
state-wide warming trend is then forecast late next week.
Elsewhere, warmer than normal conditions are expected to prevail
across the Panhandle, the Northwest, and Southwest. The Aleutians
will also be warmer than normal prior to the arrival of a front
potentially 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