Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
326 PM EST Fri Mar 09 2018

Valid 12Z Tue Mar 13 2018 - 12Z Sat Mar 17 2018

Deterministic and ensemble guidance continue to show reasonably
good agreement with an upper ridge building in and shifting
eastward over the Gulf of Alaska mid to late next week.  However,
there remains a great deal of spread and uncertainty with an
upstream trough and strong surface low possibly lifting
northeastward into the Bering Sea next Wednesday into Thursday. 
Until models come into better agreement with the amplitude,
timing, and strength of this feature, the WPC day 4-8 forecast
continued to rely heavily on a blend of continuity and ensemble
mean guidance.  The 00Z CMC and EC were slightly incorporated
early in the blend since they were a closer match to continuity
than the 00Z GFS, and they also provided some detail with a wave
of low pressure tracking near the Aleutians on Tuesday.     


Gerhardt