Alaska Extended Forecast Discussion
National Weather Service College Park MD
551 PM EDT Sat Sep 5 2026

Valid 12Z Wed 09 Sep 2026 - 12Z Sun 13 Sep 2026

...Mid-late week storm to bring hazardous weather to parts of the
western mainland...


...Guidance Evaluation and Preferences...

Models are in good agreement regarding the mid-level pattern
during the Alaska medium range period (Wednesday, 9th -- Sunday,
13th). There aren't any significant areas of model uncertainty,
however the Euro ensemble mean does develop a notable amount of
member spread related to the timing of a potent eastern Russia
trough on beginning on day 6. Therefore, it didn't feature much in
the days 4-7 blends.

A general model blend consisting of the latest deterministic Euro,
GFS, Canadian and ECAIFS were used in the days 4 and 5 blends with
weighting slightly skewed toward the Euro suite. The AiGFS is
introduced into the blend on day 6 and continued through the rest
of the period. The deterministic Euro and GFS are favored in the
blends consistently during the medium range due to good agreement
between the models. The UKMET wasn't included in the blend due to
diverging split flow solutions over the North Pacific and Gulf
early in the period.


...Pattern Overview and Weather/Hazards Highlights...

The medium range period begins on Wednesday, September 9th with a
weakened trough moving through the Central Gulf Coast toward the
Southeast. An amplifying eastern Russia low will promote a
strengthening downstream ridge over the mainland on Thursday. This
will be followed by the arrival of the aforementioned trough
Thursday night into Friday. This system will carry subtropical
moisture, which will support rain showers across the western
mainland through Saturday. The heaviest rainfall is expected to
occur along the track of the surface wave, which will possibly
propagate through the Seward Peninsula, points to the north and
interior areas Thursday--Friday. High winds are also expected
over St. Lawrence Island, Seward Peninsula and the immediate
northwestern coast due to strong warm southwesterly flow ahead of
the system.

Temperatures will remain around average for much of the state next
week. Meanwhile, temperatures will be above average to well above
average along the North Slope.


Kebede



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