Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
833 AM EDT Tue Jul 11 2017

Valid 00Z Wed Jul 12 2017 - 00Z Wed Jul 19 2017

Model guidance this morning shows solid agreement that the
subtropical high pressure system will remain anchored midway
between Alaska and Hawaii through early next week.  Typical trade
wind conditions can be expected to persist.  In the mid to upper
levels, models are indicating a couple of non-convective cyclonic
circulations, one centered to the northeast, and another to the
northwest of the Big Island.  They are forecast to merge into a
positively tilted trough while drifting west of the main Hawaiian
Islands for the next week or so.  This could set off some
additional showers and thunderstorms on Wednesday into Thursday as
a batch of more humid air drifts from east to west across the
islands.  Drier air is expected to return from Friday onward with
typical trade winds and localized showers and thunderstorms. 
However, with the presence of the positively tilted trough to the
northwest, there is a chance for some localized heavier showers in
the vicinity.

Kong