319
FXAK02 KWNH 052225
PMDAK

Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
624 PM EDT Sat Oct 5 2024

Valid 12Z Wed Oct 9 2024 - 12Z Sun Oct 13 2024

***Stormy weather on the horizon for late in the week as another
strong low likely develops over the Gulf of Alaska***

...Overview and Guidance Evaluation/Preferences...

The surface low that will be over the northern Gulf should be
steadily weakening by the middle of the week, with continued
onshore flow across the southeast Panhandle region and additional
rain showers expected.  There will likely be a second surface low
tracking across the Bering and then the Aleutians before dropping
southeast and weakening by Thursday.  Attention then turns to a
rapidly developing low pressure system for the end of the week
across the eastern Aleutians and Alaska Peninsula before taking up
residence over the northern Gulf region, with surface pressures
likely in the 970s, if not a little stronger.  Depending on the
eventual track of the low, strong winds could become an issue for
southern coastal areas, including gap wind enhancement.  An
atmospheric river event is also expected east of the main surface
low.

The 12Z model guidance suite has some timing and latitudinal
differences with the low crossing the Aleutians, with the CMC/GFS
taking a farther north track, and the UK/EC guidance taking it
quicker to the southeast.  Looking ahead to the end of the week,
there are modest model and ensemble differences with the stronger
low developing, and greater differences in regard to potential
triple point low evolution by early Saturday, with the parent low
possibly splitting up into two separate lows pivoting around each
other.  However, there is decent synoptic scale agreement with the
broad upper level gyre over the Gulf and the surface high/upper
ridge over the western Bering by next weekend.  Ensemble means
were gradually increased to about 40-50% by next weekend.

...Weather/Hazards Highlights...

The next storm developing over the Gulf Friday and into Saturday
will likely bring the return of heavy precipitation from the
mountainous terrain of the eastern Aleutians/AK Peninsula eastward
to the Prince William Sound region, with an atmospheric river
event likely accompanying it and enhancing precipitation totals
with several inches of QPF possible.  The bad weather should then
eventually reach the Southeast Panhandle over the weekend with
strong onshore flow.  Winds are expected to increase to at least
gale force, with storm force conditions also possible for some of
the coastal waters, with extremely rough seas.  High gap winds are
also likely as the low passes by.  In terms of temperatures,
readings should be slightly above normal for early-mid October
across most of the central and eastern Interior, with highs in the
30s to lower 40s, and slightly below normal for the southern
coastal areas and the western mainland.  Most locations along and
north of the Brooks Range should remain below freezing for highs.

Hamrick


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

$$