Alaska Extended Forecast Discussion
National Weather Service College Park MD
548 PM EDT Sat Jun 28 2025


Valid 12Z Wed 02 Jul 2025 - 12Z Sun 06 Jul 2025

...General Overview...

A mild/stable upper level high is forecast to meander over the
North Slope/Brooks Range mid/late week and eventually slip
southeastward into the Yukon by next weekend. Between 50-55N, a
few systems will traverse this latitude band which will keep the
highest rain chances across the Aleutians and into the Panhandle.
This pattern will be conducive to enhanced thunderstorms over the
interior which may spark some fire concerns. 


...Guidance Evaluation/Preferences...

The 12Z model guidance suite was in good agreement overall with
the handling of the synoptic features, with expected detail
differences through the period (timing/track/strength). The ECMWF
AI/ML models/ensembles were close to the dynamical consensus that
included the 12Z GFS/ECMWF/UKMET/Canadian. Though differences are
less than average, it was evident that the AI models/ensembles
were notably north of the dynamical models with the track of the
late week upper/sfc low (by perhaps 5deg latitude) perhaps due to
the strength of the upper high to the north. Favored the stronger
upper high solution which would keep the storm track a bit farther
south. The ensemble means were gradually increased to about 40%
weighting by next Sat/Sun to account for deterministic spread.

...Weather/Hazards Highlights...

The upper high will promote mild/warm temperatures with isolated
showers/storms for the North Slope/Brooks Range and much of the 
interior to start, with temperatures rising into the 80s in the 
warmest spots. Over the Tanana Valley, thunderstorm chances may
increase by later in the week as anomalous easterly flow around
the upper high increase instability when combined with warm/very
warm surface temperatures. Thunderstorms without much rainfall
could lead to fires started by lightning. 

More stratiform rain will be favored across the Aleutians and into
the Panhandle (as well as skirting coastal Southcentral) as the
Bering-Gulf systems move through from west to east. Rainfall
amounts will be light to modest and temperatures will be near to a
bit below normal due to the cloud cover. 


Fracasso




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