Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
811 AM EDT Sat Jun 11 2016

Valid 00Z Sun Jun 12 2016 - 00Z Sun Jun 19 2016

Merging of two surface high centers near 40N latitude and
subsequent strengthening of the resulting high over the next
couple days will lead to brisk trades for most of the coming week.
 Gradual weakening of the slowly retrograding high should allow
for some slackening of winds by next Fri or Sat.  Expect rainfall
to have greatest focus over windward terrain though with activity
occasionally extending to other locations as well. 

An upper level feature currently nearing 150W remains on schedule
to track over or near the islands from Sun into Mon night.  Lower
stability and precipitable water values reaching 1.50-1.75 inches
should lead to greater coverage and intensity of rainfall during
the early part of the week.  While the upper feature will continue
westward it may take until Wed or Thu for PWATs to decline
noticeably. 

Toward Fri-Sat GFS based guidance still brings lower heights aloft
to the islands from the northeast relative to most other
solutions.  The GFS scenario also shows slightly higher PWATs than
the 00z ECMWF at that time.  Over the past day the GFS has trended
a tad less amplified with the upper trough as of early Fri,
favoring at least a compromise approach.  Impact on the surface
pattern appears minimal.

Rausch