Alaska Extended Forecast Discussion...UPDATED
National Weather Service College Park MD
643 PM EDT Sat Jul 5 2025

Valid 12Z Wed 09 Jul 2025 - 12Z Sun 13 Jul 2025


...Synoptic Overview...

A strong Arctic trough and surface front will sink south across 
the northern half of Alaska next week, bringing well below average
temperatures to the North Slope and portions of the Interior and 
chances for snow showers to the Brooks Range. Meanwhile, a series
of surface low pressure systems will track across the Pacific into
the Gulf, which will result in unsettled weather through the 
period for the southern half of the state and heavy rain potential
for Southeast Alaska. 


...Guidance Evaluation and Preferences...

There is fairly good agreement on the upper level pattern through
the period, with an average amount of spread for this time period.
Model differences late in the period (next weekend) will have the
largest influence on the weather forecast. Models are all 
depicting an upper low developing over the Bering Sea that will 
slowly sink southeast across the Aleutians and eventually into the
Gulf. The evolution of this feature will greatly influence timing
and position of surface low pressure systems moving into the Gulf
towards Southeast Alaska. 

The 12Z CMC/ECMWF are well clustered, bringing a portion of the 
low's energy south across the Aleutians late Saturday into 
Sunday, but the 12Z GFS keeps the low over the Bering through the 
period. The ensemble means from the CMCE/ECENS/GEFS are all in 
good agreement on moving the upper low south towards the Aleutians
on Sunday. For this reason, the WPC forecast for next weekend 
leans more towards the ECMWF/CMC and ensemble means than the GFS.

The WPC forecast blend consisted of a near even blend of the 12Z
GFS/ECMWF/CMC/UKMET for the first two days of the period
(Wednesday-Thursday), which resulted in a middle of the road 
solution that seems to represent the pattern well. Ensemble means
from the CMCE/ECENS/GEFS were added in increasing amounts while 
the GFS was phased out of the blend for Friday through Sunday.


...Weather/Hazards Highlights...

A strong Arctic front will bring well below average temperatures
to the northern half of Alaska next week. Temperatures are 
forecast to drop 10-20 degrees below normal across the North Slope
and 5-15 degrees below normal for much of the Interior. For the 
North Slope, high temperatures are forecast to only reach the 40s 
and lows will likely be near to just below freezing. For the 
Interior, highs are forecast to be in the 50s and lower 60s and 
lows are expected to be in the 40s. Temperatures will be cold 
enough in the Brooks Range to support chances for snow showers as 
the Arctic front moves through Tuesday into Wednesday.

Though less extreme, below normal temperatures are also expected
for the South-Central Mainland and Southeast Alaska where increased
cloud cover and precipitation chances are expected through the
period as low pressure systems move into the Gulf. Given the west
to east low tracks and persistent onshore flow, Southeast Alaska 
is likely where the majority of the rain will fall next week.
Mid-next week, heavy precipitation is expected to focus on the 
Kodiak Island and Kenai peninsula areas, then the focus will shift
to Southeast Alaska Friday though the weekend. 


Dolan



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