Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
350 PM EDT Tue Jul 10 2018

Valid 12Z Sat Jul 14 2018 - 12Z Wed Jul 18 2018

Ensembles were in good agreement through the period as an upper
low slowly exits Southcentral Alaska. The 12Z/00Z GFS were a
closer fit to the eastward evolution than the 00Z ECMWF (which was
slower with the system due to a sec, so a blend of the 06Z
GEFS/00Z ECMWF ensemble mean with the deterministic GFS runs
formed a good starting point. To the north, better agreement
existed among the guidance, though there seems to be some 00Z/12Z
run-to-run oscillation. Prefer the 00Z guidance which keeps the
trough axis moving eastward steadily given the lack of downstream
blocking.

Surface front should push through the Gulf this weekend and
through the Panhandle by Monday as the Arctic front dips across
the North Slope bringing in cooler temperatures north of 65N.
Precipitation will focus along the southern coast into the
Panhandle for at least a couple days as upper ridging will be slow
to move eastward. Trailing system should stay south of the
Aleutians next week as another upper ridge noses into the western
Aleutians.

Fracasso


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