Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
745 PM EDT Mon Apr 11 2022
Valid 12Z Fri Apr 15 2022 - 12Z Tue Apr 19 2022
...Pattern and Weather/Hazard Highlights...
An upper level ridge axis is forecast to be in place across
mainland Alaska for the end of the week, with an anomalous surface
high becoming entrenched north of the Arctic Coast. A weak upper
low will likely track westward across the Interior this weekend
and then meander over the Bering. Meanwhile, a strong low
pressure system over the Bering through the end of the week should
weaken by the weekend. An even more impressive storm, which will
then be the remnants of what is currently Typhoon Malakas, is
forecast to approach the Aleutians for the beginning of next week,
along with another low entering the Gulf of Alaska.
Most of the state should begin the extended forecast period with
temperatures generally near to above average, and then colder
weather arrives in time for the weekend for the eastern half of
the state as a cold front moves in from western Canada. Milder
conditions should continue for the southwestern mainland going
into the beginning of next week. In terms of precipitation, most
of the Interior region should remain dry, and periods of rain and
mountain snow are likely for coastal regions of southern Alaska as
storm systems pass south of the coast. Windy conditions are also
possible for portions of the Aleutians for the beginning of next
week.
...Guidance/Predictability Assessment...
Differences in the model guidance are apparent as early as Friday
with the 12Z/18Z GFS well to the east of the 12Z
CMC/ECMWF/ensemble means with the low pressure area over the
Bering. For the eventual remnants of what is now Typhoon Malakas,
the 12Z GFS is extremely progressive compared to the well
clustered CMC/ECMWF/ECENS, and the GFS has also indicated a big
continuity change compared to yesterday, when it had hardly
anything for this same low pressure system. Taking these factors
into account, a blend of the ECMWF/CMC and some of the ECENS/GEFS
works well as a starting point through Saturday, and then a nearly
equal ECMWF/CMC/ECENS/CMC mean blend for the remainder of the
forecast period.
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