Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
744 PM EDT Thu May 1 2025

Valid 12Z Mon 05 May 2025 - 12Z Fri 09 May 2025

...Strong winds with moderate to heavy rain to impact southern
parts of the state through Monday...

...General Overview...

Stronger winds and moderate precipitation, and at times becoming 
heavy, is expected along the southern tier of the state and 
adjacent islands. Onshore shore flow will promote multiple round 
of moderate rain and some snow further inland. A broad upper low 
is crossing the Bering is expected to reach the Aleutians and Gulf
of Alaska by midweek which will usher in the next round of
precipitation. The Arctic surface high will be decreasing in
strength thus relaxing the easterly winds which will allow the 
below average temperatures of late will begin to moderate by the 
end of the extended period.


...Guidance/Predictability Assessment...

The latest guidance continues to depict a mean trough over the 
Gulf of Alaska, an Arctic high north of the state and a trough/low
traversing the Bering Sea toward the Gulf of Alaska for the 
extended period. Overall, agreement is fair with both the Gulf of
Alaska low and the Bering Sea low. The UKMET was significantly
faster than the cluster for the Bering Sea and was deemed an
outlier for this cycle. Although there is a fair amount of spread
without the UKMET, consensus has the Bering Sea Low approaching
the Aleutians/western Gulf by Thursday which will usher in another
frontal system and round of precipitation to the southern part of
the state.

WPC utilized a multi-model approach for the forecast, beginning
with the 12Z CMC/GFS/ECMWF. The ECMWF ensemble and GEFS means were
added to the blend for all periods beyond Day 4 to help mute the 
noise within the guidance for the Gulf of Alaska and the Bering 
Sea lows.

...Weather/Hazards Highlights...

Strong wind and widespread rain will move onshore as a robust 
surface low and associated front tracks south of the Kodiak
Island. Strong winds will impact the central Aleutians, Alaska
Peninsula, islands and the southern coast to about west of
Yakutat. Moderate/heavy rain will spread from Alaska
Peninsula/northern Kodiak Island to Malaspina Glacier. Higher 
elevations inland may have snow during this period. 

Below average temperatures across portions of the northern
Interior will begin to moderate closer to seasonal average by the
end of the extended period as the Arctic high weakens and the
easterly winds decrease. 

Campbell

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