Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
659 PM EST Wed Feb 22 2023
Valid 12Z Sun Feb 26 2023 - 12Z Thu Mar 02 2023
...Increasing threat of heavy precipitation from southwestern
Alaska to the Panhandle early to middle of next week...
...Pattern Overview, Model Guidance/Predictability Assessment and
Weather/Hazard Highlights...
The main area of concern during the medium-range period will
likely be across southwestern Alaska where model guidance
indicates an occluding cyclone will approach the region from the
southwest by early next week. This system will likely bring heavy
precipitation from west to east across the southwestern and
southern periphery of Alaska from late Monday onward. Potential
exists for moderate to locally heavy snow to impact farther inland
across interior sections of southwestern Alaska later on Monday
into Tuesday. This scenario is best supported by the ECMWF which
continues to bring a stronger cyclone across Bering Sea and with
the northern-most track among the guidance. The GFS, on the other
hand, has favored a much more southern and faster track, with the
12Z GFS keeping the southern-most track right across the Aleutian
island chain. The CMC has been in between these extremes. The
WPC fronts/pressures forecast was derived from the 06Z GFS, 12Z
GEFS, 12Z ECMWF, 12Z EC mean, and some contributions from the 12Z
CMC and CMC mean. The results are quite compatible with WPC
continuity.
For the Panhandle, the remaining heavy precipitation should be
winding down as the medium-range period begins on Sunday. Several
days of quiet weather is expected before heavy precipitation from
the aforementioned system is forecast to reach the Panhandle by
midweek. Meanwhile, the mild temperatures late in this week are
forecast to drop substantially from the 20s/30s down to the 0s/10s
across much of the mainland for highs going into the weekend as
the upper ridge breaks down. The coldest readings are expected
north of the Brooks Range, where the greatest coverage of subzero
temperatures is likely. Depending on the track and magnitude of
warm air advection with the large Bering Sea storm, temperatures
are likely to moderate some across the southwestern mainland early
next week. This will be crucial in determining how far inland the
snow will spread with the arrival of the aforementioned system.
Kong
Hazards:
- Heavy precipitation across portions of the Alaska Panhandle and
mainland Alaska, Tue-Wed, Feb 28-Mar 1.
- High winds across portions of the Aleutians, Sat, Feb 25.
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