Alaska Extended Forecast Discussion
National Weather Service College Park MD
753 PM EDT Sun Jul 13 2025

Valid 12Z Thu 17 Jul 2025 - 12Z Mon 21 Jul 2025


...Guidance Evaluation and Preferences...

The 12Z model guidance generally features good agreement across
the Bering Sea and extending east to the mainland for the
beginning of the forecast period Thursday. However, there continue
to be greater than normal differences with the weakening low
pressure system near the Alaska Peninsula and northern Gulf. The
12Z GFS and UKMET in particular were stronger and maintained the
low longer, whereas the ECMWF and CMC were weaker and more in line
with the AIFS and ensemble mean guidance, so the forecast was
hedged in that direction. The 18Z GFS trended towards the 
preferred model blend and weakens the low quicker.

Looking ahead to next weekend, the CMC is farther east with the
main Bering Sea low, whereas the ECMWF is stronger and to the
west. The guidance then suggests the low could split into two
separate lows with triple point low evolution south of the
Aleutians potentially. The guidance then suggests an upper ridge
axis builds across the Gulf going into next Monday. The ensemble
means were gradually increased to about 2/3rds by that time.

...Pattern Overview and Weather/Hazards Highlights...

A mild weather pattern will continue across mainland Alaska
through the middle to end of the week, and also into next weekend 
with a weak upper ridge in place and a weakening low pressure 
system over the Gulf. Scattered showers and thunderstorms are 
likely to develop during the afternoon and evening hours across 
much of the Interior midweek with moisture advecting northward 
across the state. There may be an increase in rain and wind for 
portions of southwestern Alaska for the end of the week, but 
currently does not appear to be a hazards level event. This would 
also help to disperse more of the wildfire smoke across western 
portions of the state. For the southern coastal areas, on and off 
showers are likely through the upcoming week, but not a wash-out.
The heaviest rainfall would be for the windward terrain of the
coastal mountain ranges. Temperatures will likely be in the 70s 
to around 80 degrees for inland areas south of the Brooks Range, 
and 50s and 60s for the coastal areas.

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