Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
819 AM EDT Sun Jun 26 2016

Valid 00Z Mon Jun 27 2016 - 00Z Mon Jul 4 2016

Over the next 7 days, a large 1031 mb high near 40N is expected to
gradually weaken by Tuesday to around 1027 mb, as the result of
troughing over the northern Pacific dropping southward,
effectively shrinking and weakening the ridge.  By later in the
week, the surface ridge rebuilds some with pressures returning to
1030mb or slightly higher.  The trough should slowly retrograde
westward across the islands through midweek.  The surface pressure
pattern over the state is in relatively good agreement through the
upcoming week between the 6Z GEFS mean and the 00Z EC mean.

The result in terms of sensible weather will be a slight veering
of the trades from northeast to more easterly, and perhaps
east-southeast at times.  By the end of the period once the ridge
re-establishes itself, an east-northeast flow should be dominant
in the lowest levels.  Precipitable water values increase to
slightly over 1.5 inches by Wednesday into Thursday morning as the
upper level trough axis moves by, with heavier showers likely. 
Besides that, the typical orographically enhanced shower activity
on the windward slopes can be expected.

Hamrick