Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
519 PM EDT Mon Oct 07 2024
Valid 12Z Fri Oct 11 2024 - 12Z Tue Oct 15 2024
...Strong low into the Gulf to bring strong winds, heavy rain, and
maritime threats next weekend...
...Overview and Guidance Evaluation/Preferences...
A strong surface low tracking from the Bering Sea on Thursday,
across the Alaska Peninsula, and into the Gulf next weekend will
be the main feature of interest across the Alaska region during
the medium range period. The latest 12z guidance shows very good
agreement on this system, which is forecast to have surface
pressures into the 950s, though some guidance suggests even
deeper. Another system looks to slide south of the western to
central Aleutians late in the period, but the GFS/ECMWF show
really good agreement here and the Canadian didn't lag too much.
For the winds, pressures, fronts, and QPF, an even blend of the
12z GFS, ECMWF, UKMET, and Canadian were used initially, before
incorporating some of the 12z NAEFS mean and 00z ECMWF ensemble
mean later on to account for uncertainty. The remainder of the
grids were more 19z NBM based.
...Weather/Hazards Highlights...
The storm moving into the Gulf on Friday will bring a threat for
heavy precipitation progressing east to west from the mountainous
terrain of the eastern Aleutians/AK Peninsula to the Southern
Coast, and eventually the Panhandle. An atmospheric river event is
likely with precipitation totals of several inches of QPF, and
snow in the higher terrain. Unsettled wet weather will linger for
a few days across the Panhandle region as the low settles into the
Gulf. Gusty and strong winds will also be a threat across the
entire region, with storm to hurricane force winds possible over
the water, and strong gap winds within the usual favorable
locations. Significant waves will present a major threat for
maritime interests as well. Some lighter precipitation (snow) may
reach into interior Alaska. 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.
Roth/Santorelli
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