Prognostic Meteorological Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1
000
FXAK02 KWNH 272023
PMDAK

Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
423 PM EDT Sun May 27 2018

Valid 12Z Thu May 31 2018 - 12Z Mon Jun 4 2018

Recent runs of the ECMWF and GFS looked reasonably aligned with
the large scale pattern over Alaska through Friday night.
However, a fair amount of mesoscale variability among ensemble
members suggests there is still quite a bit of uncertainty with
the details of the forecast, so the WPC forecast still
incorporated some continuity and ensemble means into the Day 4-6
(Thursday to Saturday) blend.  By next Sunday, the GFS is much
more amplified with the upper ridge over Alaska and farther south
with a second upper low entering the Gulf of Alaska, and without
one piece of deterministic guidance offering much stability with
the pattern, the WPC forecast was heavily weighted towards
ensemble means for the second half of the forecast period.



WPC medium range Alaskan products including 500mb, surface
fronts/pressures progs and sensible weather grids can be found at:

http://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif
www.wpc.ncep.noaa.gov/alaska/akmedr.shtml
http://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html


Hamrick


$$





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.