Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
556 PM EST Sun Nov 6 2022
Valid 12Z Thu Nov 10 2022 - 12Z Mon Nov 14 2022
...Synoptic Scale Overview...
A powerful low pressure system is forecast to approach the central
Aleutians towards the end of the week and then weaken as it enters
the Bering Sea. There should be a broad area of low pressure over
the Bering and Aleutians through next weekend with multiple
shortwaves reinforcing the trough axis here. Upper level ridging
and surface high pressure will continue to govern the overall
weather pattern across the Interior. Areas of heavy precipitation
are possible from the eastern Aleutians to the Kenai Peninsula
with moist onshore flow.
...Guidance/Predictability Assessment and Preferences...
The 12Z model guidance has come into a little better focus with
the low pressure system approaching the Aleutians late in the
week, although the GFS and the GEFS means continue to show a more
eastward trajectory towards the Gulf of Alaska. This is in
contrast to the CMC/ECMWF/UKMET, which support a more northward
track across the southern Bering Sea. The WPC forecast was hedged
more in this direction compared to the GFS/GEFS idea. The next
trough developing over the Bering/Aleutians next weekend is
reasonably well supported in the guidance, although the CMC
becomes a bit slower in its progression. The models continue to
agree on the upper ridge axis holding strong across the Interior.
...Sensible Weather and Potential Hazards...,
Temperatures are expected to gradually warm up going into the
extended forecast period with highs returning to the 20s and low
30s for most of the mainland, with the exception of some 0s and
10s for some of the more sheltered valley locations. Mostly
cloudy conditions should be prevalent across most of the state.
Rain chances are expected to be highest across the Aleutians and
near the higher terrain of the southern coastal areas, with the
potential for a few inches of QPF for the Thursday through Sunday
time period, with this mainly in the form of heavy snow for the
higher elevations. Winds should be highest across the
southwestern mainland into the Aleutians, depending on the
eventual track and strength of the North Pacific storm system.
There is greater potential for higher winds in portions of the
Aleutians Wednesday night and Thursday, perhaps reaching storm
force if the track and depth of a pair of cyclones are most
favorable.
Hamrick
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