Alaska Extended Forecast Discussion
National Weather Service College Park MD
748 PM EDT Sat Aug 8 2026

Valid 12Z Wed 12 Aug 2026 - 12Z Sun 16 Aug 2026

...Overview...

An upper/surface low pressure system will move north through the
northern Pacific toward the Alaska Peninsula mid to late week,
bringing ample moisture for heavy rain and some high wind threat
to Southcentral regions. Another low upstream is forecast to dive
through the western Bering Sea toward the Aleutians, and these
should interact and combine into later week and next weekend.
Meanwhile, blocky upper ridging will be persistent over much of
the Mainland, leading to continued above average temperatures.


...Guidance Evaluation and Preferences... 

The first low pressure system moving toward the AKPen is 
initially in good agreement among the models. Upstream, the low 
moving south/southeast through the Bering ends up a bit more 
questionable into Thursday-Friday at the surface. The model 
consensus seems to be for the surface low to be near or north of 
the Aleutians, but the 12Z ECMWF surface low position was south of
the Aleutians, affecting wind direction etc. Then, models show 
some typical spread with those two lows interacting and merging, 
with uncertainty on timing of the eastern low likely weakening. 
Over the weekend, there is growing model spread with the potential
for a somewhat strong surface low to develop in the northern 
Pacific as the lows combine and possibly get enhanced by upstream 
energy coming southeast through the Bering Sea. The 12Z/18Z GFS 
seemed quick to develop this low by Saturday, but the AIGFS 
supports the GFS, while the AIFS also indicates a low farther west
and a bit weaker by then, and the 12Z ECMWF does show a 
reasonably strong low by Sunday. This is a somewhat new model 
trend, so will continue to watch. Generally, guidance shows good 
agreement with the ridge aloft, oriented across the northeast 
Pacific into the Mainland Wednesday-Thursday and shifting to be 
across western Canada bending westward into the Mainland by Friday
into the weekend.

The WPC forecast was based on a multi-model blend early in the 
period, with increasing proportions of ensemble means to half Day 
7 and more Day 8 amid increasing spread. 


...Weather/Hazards Highlights...

Moisture will flow into much of Alaska given mean southerly flow 
through the period, producing rain chances. The heaviest rain 
amounts are likely Wednesday night to Thursday across favored 
coastal/upslope areas of the Alaska Peninsula, Kodiak Island, and 
the Kenai Peninsula, as the low pressure/frontal system moves 
through and provides forcing and moisture focus for a broad couple
of inches of rain. The low may also funnel strong winds into 
parts of the AKPen and Cook Inlet and vicinity. Rounds of lighter 
to moderate rain showers are likely farther north across the 
western Mainland and Alaska and Brooks Ranges. A potentially 
strengthening northern Pacific low could lead to another round of 
moderate to heavy rain for the AKPen to Southcentral next weekend.
The eastern Interior to Southeast AK should mostly be dry 
underneath upper ridging through late week, though chances for 
showers may increase by next weekend depending on the eventual 
evolution with that low.

Temperatures will be broadly warmer than average in most areas 
through the period, given southerly flow and ridging aloft. Highs 
in the 70s and 80s are forecast for Interior areas for multiple 
days. Southcentral can expect highs around 70, with 60s and upper 
50s for southern coastal areas. The coastal towns of the North 
Slope could see 50s for highs, with 60s to around 70 in the Arctic
Plains.


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