Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
644 PM EDT Tue Apr 12 2022
Valid 12Z Sat Apr 16 2022 - 12Z Wed Apr 20 2022
...Deep Extratropical Low associated with current west Pacific
Typhoon Malakas to affect the Aleutians Sunday-Tuesday...
...Pattern and Weather/Hazard Highlights...
A deep extratropical low associated with current west Pacific
Typhoon Malakas is forecast to approach the Aleutians for the
beginning of next week. Wrapping rains driven by high winds with
the significant storm will also offer a widespread maritime threat.
Otherwise, an upper level ridge axis should remain in place across
much of mainland Alaska, with a surface high settling north of the
Arctic Coast. However, a weak undercutting 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.
In this pattern, much of the state should begin the period with
temperatures generally near to above average, and then colder
weather arrives in time for the weekend for eastern areas of the
state as cold air moves in from western Canada. Milder conditions
should continue into early next week for northern Alaska near a
closed upper high and over the southwestern mainland with deep
Aleutian system affect. In terms of precipitation, most of the
Interior region should remain dry and any periods of rain and
mountain snow will likely be modest for southern and southeast
Alaska as storm systems spin well offshore.
...Guidance/Predictability Assessment...
Guidance signal has improved with respect to a track to affect the
Aleutians Sunday-Tuesday of a deep extratropical low associated
with current west Pacific Typhoon Malakas and the WPC Hazards
Outlook desk has introduced graphical threats for the system. A
composite of best clustered guidance from the 12 UTC
GFS/ECMWF/Canadian and GEFS mean through medium range time scales
seems to reasonably fit the latest official system track and also
for most other features evident over the rest of Alaska. This
solution maintains good WPC product continuity and system detail
consistent with a pattern with near average predictability.
Schichtel
Hazards:
- Heavy precipitation across portions of the Aleutians, Sun-Mon,
Apr 17-Apr 18.
- High winds across portions of the Aleutians, Sun-Mon, Apr 17-Apr
18.
- Heavy precipitation across portions of eastern Aleutians to the
Alaska Peninsula, Tue, Apr 19.
- High winds across portions of the eastern Aleutians to the
Alaska Peninsula, Tue, Apr 19.
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