Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
712 AM EST Fri Nov 21 2014

Valid 00Z Sat Nov 22 2014 - 00Z Sat Nov 29 2014

The 21/00Z forecast cycle offered a good depiction of the sensible
weather scenario for Hawai'i through day 4---with more detail on
the next frontal system migrating from the Aleutians to the east
central Pacific by day 5-6.

The 21/00Z ECENS/GEFS were in much better 'synch' with the mass
fields through day 5 and it's the deterministic 21/00Z
GFS-Canadian that have a deeper (closed 500mb low) solution
migrating northeastward into the mid-latitude east Pacific by
26/12Z. The GFS-parallel and ECMWF carry more of a positive-tilt
trough eastward---but essentially, the stalled closed low solution
from yesterday is gone.

And the trend is---a progressive solution for a surface frontal
passage for Monday, more in line with yesterday's GFS
(20/00Z-20/06Z cycles). The frontal passage should alter the
current wind field pattern, and depending on the forward speed of
the exiting trough---the western Islands will likely be affected
by one or more shear lines developing in the wake of the departing
system.

Beyond day 5, a mass-field blend of the 21/00Z GEFS/ECENS means
should handle the timing of heights rises (a migratory upper-level
ridge) moving west to east along 20N latitude.

Vojtesak