Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
753 PM EDT Sun Apr 17 2022
Valid 12Z Thu Apr 21 2022 - 12Z Mon Apr 25 2022
...Guidance/Predictability Assessment...
The 12Z model guidance suite has a decent overall depiction of the
two main low pressure centers of interest over the North Pacific
on Thursday, although the GFS/GEFS is ahead of the non-NCEP
guidance for the big storm just south of the Aleutians. The
models are still well clustered for the weakening remnants of
former Typhoon Malakas over the Gulf and this should dissipate by
Friday. The UKMET solution is close to the ECENS and between the
western CMC/ECMWF and the eastern GFS solution for the Aleutians
storm entering the Gulf region. By Saturday, the CMC is likely a
little too slow with this system, and the GFS is stronger with a
closed low emerging from eastern Siberia. It is interesting to
note that model agreement actually improves some by the end of the
extended forecast period next Monday across the Gulf with the main
closed upper level gyre, and the GEFS/ECENS are also in good
agreement there, but models diverge more with the next system
approaching the Aleutians/Bering Sea by that time.
...Overview Weather/Hazard Highlights...
With the remnants of what was formerly Typhoon Malakas primarily
gone by Thursday, attention turns to a rather large low pressure
system near the Aleutians with strong winds and extremely rough
seas to end the work week, along with multiple rounds of
wind-driven wind for the central and eastern Aleutians. Going
into next weekend, this low is forecast to emerge over the Gulf
albeit in a weaker form. There will be enough of a moisture plume
directed at the coast to produce widespread showers from the
Alaska Peninsula to the southeast Panhandle region for Friday
through Sunday, with the potential for 1 to 3 inches of rain for
the lower elevations, and heavy mountain snow. Elsewhere, much of
the Interior and North Slope should remain dry, with temperatures
generally running above average across much of the mainland. The
exception would be for the southern coastal areas with some below
average readings owing to increased clouds and precipitation.
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