Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
546 PM EDT Sun Apr 09 2023
Valid 12Z Thu Apr 13 2023 - 12Z Mon Apr 17 2023
...Cold pattern for much of Alaska this week and beyond...
...Overview with Guidance Evaluation/Predictability Assessment and
Weather/Hazard Highlights...
An amplified mean upper trough will persist over mainland Alaska
this week along with a cold temperatures and occasional localized
light snow focus from the Interior to the North Slope. The overall
cold to much below normal cold pattern is expected to hold for
much of Alaska this April as per latest guidance from the Climate
Prediction Center.
Meanwhile to the south, surface lows will consolidate/deepen and
re-develop over the Gulf of Alaska late week into next week with
upper trough amplification and persistence as aided by multiple
stream energies. Expect periods of high winds/gap winds are
possible on the backside of these maritime lows with some focus
from the eastern Aleutians to the Alaskan Peninsula and Kodiak
Island. Unsettled weather with periodic wrapping precipitation
will linger for the southern coastline of Alaska, but more so for
the Southeast Panhandle with protracted lead moisture potential as
the main low system position is forecast to meander over the
east-central Gulf of Alaska. Precipitation amounts do not appear
to be excessive over the Southeast this week, but should be
widespread and enhanced over favored terrain.
Guidance shows a quite similar pattern evolution though these
med-range time scales, but offer less than stellar run to run
continuity with features rotating within main upper trough
positions both over the mainland and the Gulf of Alaska.
Accordingly prefer a blend of the 12 UTC GFS/ECMWF/CMC and
GEFS/ECMWF ensemble means, with greater weighting on the ensemble
means given uncertainties. This forecast plan was collaborated
with local Alaskan weather offices and associated WPC product
continuity is well maintained in this manner.
Schichtel
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