Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
800 AM EDT Sun Jun 17 2018

Valid 00Z Mon Jun 18 2018 - 00Z Mon Jun 25 2018

Most guidance maintains fairly good agreement and continuity
regarding the forecast over the next seven days.  During the first
half of this week expect Pacific systems and their trailing fronts
to weaken an already modest surface ridge just north of the state.
 This will allow for some land and sea breeze influence on shower
activity.  Rainfall should be on the light side with an upper
ridge just west/north of the area helping to offset a band of
higher precipitable water values dropping into the region from the
north.  While there will be another front crossing the
mid-latitude Pacific, still expect an overall trend toward
strengthening surface high pressure over the eastern half of the
Pacific late this week through the weekend.  This evolution will
lead to moderate or brisk trades with more windward shower
emphasis.  Precipitable water values should decrease relative to
the early/mid week time frame though there may still be a pocket
or two of enhanced moisture embedded within the easterly flow. 
Best focus for light to moderate rainfall next weekend will likely
be over the Big Island given terrain enhancement and potential for
an upper level weakness to approach from the east.  Note that the
06Z GFS compares much better to the full model/ensemble mean
consensus for this upper feature than the slower 00Z GFS.

Rausch