Alaska Extended Forecast Discussion
National Weather Service College Park MD
727 PM EDT Thu Jul 24 2025
Valid 12Z Mon 28 Jul 2025 - 12Z Fri 01 Aug 2025
...Overview...
A closed low will remain over the Gulf of Alaska within an
elongated trough through the extended period along with upper
level ridging over the Aleutians and Bering. This blocky pattern
will slow the lows progression along with weakening. Showers will
spread across portions of the Interior and across the southern
coast and Panhandle. Another low developing well west of the
Aleutians by midweek may usher in precipitation to the Aleutians
as early as Thursday.
...Guidance Evaluation/Preferences...
The latest guidance remains very clustered with the Gulf of Alaska
low and the associated surface low and frontal system. However
there is a growing signal for another trough and possible closed
low to develop over the North Pacific/western Bering Sea that will
progress eastward toward the Aleutians. There is a significant
amount of spread with the location, depth and timing of this
feature. The means provided less noise but kept the general idea
of a deepening low over this part of the globe. Given poor
consensus, the confidence for sensible weather and QPF is below
average for the Aleutians in the latter period.
The WPC forecast used a multi-model blend initially and included
the GEFS mean, NAEFS and EC means by Tuesday/Wednesday increasing
weighting to 45 percent by Friday. This approach helped maintain
continuity from the previous forecast while reduces the noise with
the next feature.
...Weather/Hazards Highlights...
Appreciable rainfall totals expected over the course of multiple
days. Wet snow is possible in higher elevations of the Alaska
Range. A front approaching, along with potential upper troughing
coming into the Bering Sea and vicinity, could lead to rain
chances across the Alaska Peninsula and western Mainland spreading
east across the Mainland. A renewal of precipitation likely to
the Aleutians later in the period.
Daily maximums will generally be in the 70s in most Interior
areas. Temperatures may cool back down in the western Mainland
early next week depending on the evolution of the upper trough.
Southeast Alaska can expect temperatures to remain near to below
average with the low in the vicinity and increased cloud cover.
Campbell
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