Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
713 AM EST Sat Nov 29 2014

Valid 00Z Sun Nov 30 2014 - 00Z Sun Dec 07 2014

Expect brisk trade winds to lighten slightly over the next couple
days as high pressure to the north of the state weakens a little. 
Latest guidance is consistent in bringing precipitable water
values to a relative minimum, just under an inch, in the Sun-Mon
time frame so expect windward favored showers to be on the light
side.

From Tue onward the model/ensemble guidance has become more
diverse than in recent days.  Relative to other solutions the
00z/06z GFS runs are deeper with the upper level energy that
amplifies to near 170W by Thu, leading to stronger surface
development and ultimately a wetter pattern for the islands as the
wave/front approach the islands late next week.  On the other end
of the spectrum the 00z ECMWF/EC mean have a much more diffuse and
positively tilted trough that would increase moisture for a time
but primarily over the southern islands.  The 00z/06z GFS parallel
runs offer yet another option with energy aloft separating far
enough westward to support an increase in moisture/rainfall to an
extent that is between the GFS/EC extremes.  The surface pattern
in the parallel runs is somewhat similar to the 00z GEFS mean. 
Current spread and continuity changes make it difficult to select
a particular scenario with much confidence.  However on balance
the overall evolution aloft seems to favor some increase in
moisture/rainfall by Fri so the 00z GEFS mean and 00z/06z GFS
parallel runs may be the best starting point for the islands and
vicinity at this time, possibly tempered a little by the ECMWF/EC
mean given that their forecast is probably closest to continuity.

Rausch