Alaska Extended Forecast Discussion
National Weather Service College Park MD
642 PM EDT Mon Jul 28 2025

Valid 12Z Fri 01 Aug 2025 - 12Z Tue 05 Aug 2025


...Late week Aleutians/Alaska Peninsula Heavy Rain and Enhanced 
Wind/Wave Threat...


...Overview...

The primary upper flow features to affect Alaska from late this 
week into early next week will be a slow to dislodge closed
low/trough over the Gulf of Alaska, ridge re-building over the 
Interior/North Slope and closed low/trough emergence over the 
Aleutians/Bering Sea. The latter will support development of a
well organized southern Bering Sea surface low pressure system 
into late week/weekend whose energies and triple-point low
developments translate slowly work downstream to the Gulf of 
Alaska to kick/replace the aforementioned lead Gulf of Alaska closed
low going into early next week. This emerging system track offers
an uncertain long fetch moisture connection to current West 
Pacific Tropical Storm Krosa to monitor for system efficiency.

...Guidance Evaluation/Preferences...

Model and ensmeble forecast clustering have overall improved, 
bolstering forecast confidence for much of this period. The WPC 
forecast was mainly derived from a blend of the 12 UTC 
ECMWF/Canadian/UKMET models and GEFS/ECMWF/Canadian ensemble 
means. This blend shows a slow transition of a blocky pattern 
and a building well downstream moisture connection to current 
West Pacific Tropical Storm Krosa. There are still uncertainties 
in the forecast that include the shape and strength of upper 
ridging building over the Interior/North Slope to monitor. The 
broad blend process used should act to mitigate lingering smaller 
scale variances as consistent with individual predictability 
while manual edits act to maintain/deepen offshore surface low 
pressure system strengthes with favorable support.

...Weather/Hazards Highlights...

Expect much above normal temperatures across especially the 
Interior/North Slope where some spots may reach 80F by late week 
given and with anticipation of favorable upper ridge development.

To the south, moisture and waves rotating around the northern
periphery of a well offshore Gulf of Alaska closed low position
offers periodic rounds of light to locally enhanced precipitation
from Southeast to SouthCentral Alaska inland to the Alaska Range.

Meanwhile upstream, a plume of heavy rain in unsettled flow will 
overspread the Aleutians and into the Bering Sea into later this 
week. The main focus should then work into the western Alaskan 
Peninsula as a deepened low pressure system enhances winds/waves 
and draws in enhanced moisture with a connection to Krosa. The 
main low is forecast to settle in the southern Bering Sea into 
the weekend. Triple point lows will transition with more 
uncertainty downstream into the Gulf of Alaska from the weekend 
into early next week to slowly spread enhanced rain and unsettled 
flow over the Gulf to coastal southern and Southeast Alaska.

Schichtel




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