Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
756 AM EDT Fri Mar 31 2017

Valid 00Z Sat Apr 01 2017 - 00Z Sat Apr 08 2017

The guidance are in good agreement in and near the 50th state into
Tuesday.  Thereafter, the 00z Canadian becomes a fast outlier with
energy aloft which leads to a very quick cyclone progression
towards the Pacific Northwest which leads to a more defined
boundary remaining near Hawai'i, rather than retreating ahead of
the more realistic progression shown by the 00z ECMWF/06z GFS
solutions, which are more supported by the various ensemble means.
 The 00z Canadian is not preferred. 

The upper level pattern over Hawai'i for the upcoming week
features large-scale ridging in the Horse Latitudes into Tuesday. 
A weak front/shear line moves into the main islands Tuesday which
should weaken out of existence or retreat by late Wednesday.  A
new boundary entering the Papahanaumokuakea National Marine
Monument late Wednesday is expected to slowly march through the
main islands Thursday and Friday.  Each boundary should lead to
slight enhancement to the diurnal shower regime in its vicinity. 
Because of the incursions of the two fronts, trade winds become
quite weak from Monday night into Friday morning, before
freshening out of the northeast late Friday.  Precipitable water
values look a touch low through the period, 1-1.25", which should
otherwise keep shower activity slightly less than usual along
windward slopes.

Roth