Alaska Extended Forecast Discussion
National Weather Service College Park MD
657 PM EDT Sun Jun 1 2025

Valid 12Z Thu 05 Jun 2025 - 12Z Mon 09 Jun 2025


...Moderate to heavy rain to impact portions of the Southern 
Coast and Alaskan Panhandle into the end of the week...

...Overview...

The extended range period starts Thursday with a weakening upper 
low over mainland Alaska. Energy rotating around this low and also
combination with an Arctic low to the north will help maintain 
general troughing over Alaska through at least the weekend. To the
South, an upper low/surface low will slide east south of the 
Aleutians and in a more northerly direction towards the 
Peninsula/Southern Coast as upper ridging builds over the Gulf and
Panhandle late week. Moderate to heavy rainfall may be a concern 
early in the period (mid next week), but a generally unsettled 
pattern may continue through the period. Another round of heavier 
rain may impact the Southern Coast region late in the period, but 
with a lot more uncertainty in the timing and amounts still at 
this point.


...Guidance Evaluation/Preferences...

Overall, there is generally good agreement on the pattern, moreso
in the early part of the period. The guidance becomes more 
chaotic by about Day 6 with the evolution of the trough/low south 
of the Aleutians and its eventual track northward. The GFS was the
biggest outlier suggesting a splitting of energies, sending a 
weak shortwave into the Gulf and maintaining a much stronger cut-
off low south. The better consensus of models and ensembles 
suggests stronger ridging over the Gulf and a general east to 
north east progression of this system (maintaining one trough, 
rather than split flow). Much of the guidance shows another 
surface low reaching the Southern Coast by next weekend. Even 
bigger questions arise Day 7 and 8 (Sunday and Monday) with the 
evolution of this trough/low, with the ECMWF a bit of an outlier 
right now showing a very blocky flow pattern beginning to set up 
next Monday. The WPC forecast today used a blend of the 
deterministic solutions Days 4 and 5, but begin increasing 
influence of the ensemble means Day 6 and especially day 7 and 8 
(with no inclusion of the GFS at all past Day 5). Overall, this 
maintained pretty good continuity with yesterdays forecast.


...Weather/Hazards Highlights...

A weakening low and cold front in the Gulf will continue a steady
stream of moisture directed towards Southeast Alaska on Thursday,
slowly drifting southward on Friday. Moderate to heavy rainfall 
may be possible with this system. After this, rainfall intensity 
should decrease but showers will continue all along the coastal 
regions from the Aleutians to the Panhandle, and even farther 
inland towards the Brooks range with general troughing around. 
Ridging into the Panhandle may help keep things more dry for that 
region. Another low lifting northward may increase precipitation 
again for parts of the Peninsula and Southern Coast but with much 
more uncertainty in the amounts and impacts.

High temperatures across much of the state will be below normal 
through the period underneath of weak troughing. Some moderation 
at times is possible, particularly for southwest or southern 
regions as upper ridging moves through. The greatest below normal 
anomalies will be across the Northern Slope region under the 
influence of an Arctic upper low.

Santorelli



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