Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
621 PM EDT Sun May 29 2022
Valid 12Z Thu Jun 02 2022 - 12Z Mon Jun 06 2022
...Overview and Weather and Hazard Highlights..
The upcoming early June pattern still seems fairly quiet for
Alaska. An early week warm upper ridge over the Interior shows
some weakness in guidance into mid-late week to offer lingering
chances for scattered precipitation and some temperature
moderation. This ridge separates Arctic upper troughs/lows to the
north of Alaska that periodically force several fronts through the
North Slope and northern Interior from several closed upper
level/surface lows in the North Pacific. In this flow, a
lead/lingering closed low and effects will slowly weaken well
offshore over the southern Gulf of Alaska this week, but expect
some modest precipitation over coastal southern/southeast Alaska
later period. Meanwhile, a closed upper trough/low with moderate
main/triple point surface lows will slowly transition eastward
from just to the south of the unsettled Aleutians to well offshore
over the western Gulf of Alaska as a moderate maritime threat.
...Guidance/Predictability Assessment...
Guidance solutions remain pretty well clustered overall at larger
scales for much of the Alaskan domain and vicinity, but pesky
small-mid scale differences remain. This is mainly evident with
higher latitude impulses working into the North Slope and
Interior. A WPC/Alaskan WFO collaborated decision to use a
composite blend of the 12 UTC GEFS/NAEFS/ECMWF ensemble means
seems to provide a good/consistent forecast basis over the
Mainland and the North Pacific/Gulf of Alaska where main offshore
low solutions remain well clustered. Manual edits were applied to
offset the averaging process as needed to best maintain product
continuity in an overall pattern with average to better
predictability.
Schichtel
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