Alaska Extended Forecast Discussion
National Weather Service College Park MD
746 PM EDT Wed Jun 25 2025


Valid 12Z Sun 29 Jun 2025 - 12Z Thu 3 Jul 2025


...Guidance Evaluation/Preferences...

The 12Z model guidance suite is in reasonably good agreement for
the beginning of the period Sunday, but model differences become
more apparent going into early next week, especially across
western portions of the domain where the eventual remnants of T.D.
Sepat will go. There is general agreement for a building upper
ridge across the mainland and a trough over the Gulf and
Aleutians, with models varying on specifics. The use of the
ensemble means were increased to about half by next Thursday.


...Weather/Hazards Highlights...

A broad upper level low with reinforcing surface lows will be
present across the northern Gulf through most of the forecast
period. The upper ridge axis appears likely to build back in north
across the central and northern mainland going into the middle of
next week and potentially forming a rex block type pattern as a
closed upper high could form. Meanwhile, a trough approaches from
eastern Siberia Tuesday into Wednesday, but does not appear to be
all that impactful at this time. 

Much of the mainland will start off dry for Sunday, but there will
likely be an increase in shower and thunderstorm coverage going
into early next week across eastern portions of the Interior.
Relatively moist northeasterly flow approaching the central and
eastern portions of the Alaska Range will increase the potential
for heavier rainfall, with the highest totals where there is an
upslope flow component where 1 to 2 inches will be possible.
Therefore, after consultation with the local forecast offices, a
heavy rainfall area has been introduced on the WPC hazards chart
for the 29th and 30th for east-central portions of the Interior.
This rainfall would help to mitigate any ongoing fire weather
concerns. Off and on showers are also expected for southeast
Alaska as moist onshore flow continues courtesy of the loitering
low over the northern Gulf.

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