Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
244 PM EST Mon Nov 12 2018

Valid 12Z Fri Nov 16 2018 - 12Z Tue Nov 20 2018

Models and even the ensembles have struggled to consistently
capture the forecast outside of the largest scale. Even the ECMWF
ensemble mean, which had been least susceptible to cycle-to-cycle
variability, has shifted both over the high latitudes in addition
to across the lower 48. The 00Z ECMWF recent GFS runs matched
fairly closely to the ensemble consensus early in the period
(Fri-Sat) which served as a good starting point. Lead system in
the Gulf Friday will lift northward and northeastward into the
Panhandle as its southern portion stretches to the south aloft,
becoming the main system as the northern portion weakens into the
ridge. On its heels will be another system moving through the
Aleutians but with a large N-S spread in track. Tried to balance
continuity (to the south) with the trend northward at a bit
quicker pace than 24 hrs ago. That will move into the Gulf next
Sun/Mon as another system slides eastward along or just north of
the Aleutians -- but with a lot of uncertainty per recent runs.
Wet pattern for southeastern Alaska/Panhandle with the upper ridge
axis near 130W (NNW-SSE).


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