Alaska Extended Forecast Discussion
National Weather Service College Park MD
724 PM EDT Thu Oct 16 2025

Valid 12Z Mon 20 Oct 2025 - 12Z Fri 24 Oct 2025


...High winds and heavy precipitation for the Aleutians and 
Alaska Peninsula this weekend and possibly spreading eastward...

...Overview...

A broad upper low is forecast to be in place atop eastern Siberia
into the Bering Sea into early next week, with rounds of 
potentially impactful cyclones on its periphery. A large and deep 
surface low is forecast to pass near the Aleutians and Alaska 
Peninsula Sunday and bring heavy rain/precipitation and high 
winds then tracking east across the Gulf of Alaska Monday-Tuesday. 
It may bring the heavy precipitation into Southcentral and 
Southeast Alaska. Another wave of upper troughing and a weaker 
surface low look to track near the Aleutians once again early next
week, and then settle into the Gulf of Alaska while the broad 
cyclone aloft reorients a bit east into Bering Sea by midweek.


...Guidance Evaluation/Preferences...

Guidance continues to depict a notably strong surface low 
(generally in the 950s or 960s mb) crossing the Aleutians just
prior to the start of the extended period. This feature will 
usher in high winds with it, although the associated QPF has 
trended more offshore thus reducing the threat for heavy rain for
portion of the Aleutians, AKPen and southcentral Mainland. The 
low system is progged to move east across the Gulf of Alaska. 
Unlike the previous runs, there are intermittent time steps where 
the CMC has trended toward the track/evolution of the GFS and thus
has some degree of usability. Upstream, another surface low looks
to track east from the southern tip of the Kamchatka Peninsula 
early next week. Models have this low's central pressure generally
in the low 980s. The low looks to arrive to Kodiak Island and the
Gulf of Alaska by Tuesday and then persist there through 
Wednesday and Thursday. The preferred blend leaned toward a GFS/EC
and their means for the extended period with small, intermittent 
inclusions of the CMC.


...Weather/Hazards Highlights...

The latest guidance has backed off on QPF amounts for the 
Aleutians to the Alaska Peninsula, keeping the highest amounts
over the Gulf. However, these areas can expect high winds with 
the strong surface low for the start of the week. Precipitation 
should spread into Southeast Alaska (the Panhandle) regardless, 
beginning Monday. The second low will provide some moderate rain 
to the Aleutians and AKPen again into Monday, likely reaching 
Southcentral and Southeast by Tuesday with moderate to heavy 
amounts. The slower- moving pattern by the middle of next week 
will be favorable for moisture streaming into Southeast Alaska for
multiple rounds of precipitation next week. Thus will continue to
monitor if this deserves a hazard area on the Day 3-7 Hazards 
chart, despite the high criteria for this time of year since the 
region can handle a lot of precipitation. Farther north across the
Mainland, most areas should stay mainly dry early next week 
(after a few rain and snow showers early Sunday), until Tuesday 
and Wednesday when coverage of light precipitation may increase as
energy aloft gets closer and funnels some weak moisture ahead of 
it. 

Lower elevation areas of the Mainland will mostly be above 
average temperatures (especially for lows) through the period, 
with chillier temperatures in the Brooks and Alaska Ranges. The 
Lower Kuskokwim delta may cool to slightly below average by 
Wednesday- Thursday as energy aloft moves in. Southeast Alaska 
should be generally near average for temperatures in the 40s and 
low 50s.


Campbell/Tate




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