Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
817 AM EDT Mon Jul 23 2018

Valid 00Z Tue Jul 24 2018 - 00Z Tue Jul 31 2018

Expect the state to remain on the periphery of surface high
pressure well to the north/northeast.  This will support moderate
trades through much of the period and rainfall focusing over but
not fully limited to windward terrain.  One area of moisture and
associated surface trough is currently progressing through the
islands and will continue westward with a band of drier air moving
in for Tuesday and into Wednesday.  Over the past day guidance has
come closer together for the next area of moisture that may
provide some shower enhancement, especially over the Big Island,
late Wednesday or Wednesday night through at least Thursday.  The
axis of highest precipitable water values will continue
progressing to the west with time but model/ensemble guidance
agrees that PWATs should remain over 1.50 inches at most locations
through next Monday.  An upper ridge will persist over the area
for most of the period and possibly tone down shower development
to some degree.  Guidance is suggesting this ridge may begin to
weaken or at least drift westward by around Sunday-Monday.

Rausch