Alaska Extended Forecast Discussion
National Weather Service College Park MD
737 PM EDT Tue Jul 29 2025
Valid 12Z Sat 02 Aug 2025 - 12Z Wed 06 Aug 2025
...General Overview...
The primary upper flow features to affect Alaska from this
upcoming weekend into early next week will be a weakening low
pressure system over the Gulf of Alaska, upper level ridging over
the Interior and North Slope region, and closed low/trough
emergence over the Aleutians and the Bering Sea. The latter will
support development of a well organized southern Bering Sea
surface low pressure system into the weekend whose dynamics and
triple-point low development affect the North Pacific and the
southern coastal areas going into next week.
...Guidance Evaluation/Preferences...
The 12Z model guidance starts off in good overall agreement this
weekend across the Alaska domain. Differences are apparent with
the placement of the main upper low situated across the Bering
Sea, with the GFS generally north or northwest of the model
consensus going forward into early next week. The Canadian model
becomes considerably stronger with a separate storm system moving
in south of the Aleutians by next Tuesday/Wednesday and loses
ensemble support, so it is reduced in the model blend by Tuesday.
The ensemble means were increased to about half by next Wednesday.
...Weather/Hazards Highlights...
An atmospheric river of enhanced moisture will lead to heavy rain
across the eastern Aleutians and the Alaska Peninsula later this
week and into Saturday. A relatively strong low pressure system is
expected to bring higher winds and waves across the offshore
waters in this area. The main low is forecast to settle over
southern Bering Sea into the weekend. A triple point low is then
likely to develop and then move into the Gulf from the weekend
into early next week, with potential additional unsettled flow
over the Gulf to coastal southern and Southeast Alaska.
Warm temperatures are expected across much of the Interior and
even across the North Slope going into the weekend with an upper
ridge axis in place, with highs well into the 70s and even some
lower 80s, and lows generally in the 50s.
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