Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
657 AM EST Thu Dec 22 2016

Valid 00Z Fri Dec 23 2016 - 00Z Fri Dec 30 2016

Latest guidance maintains good continuity and agreement for the
forecast through the weekend into early next week, as a series of
low-mid level anticyclones move slowly east across latitudes north
of the islands. In between highs, such as Friday December 23, a
weakness in the ridge results in slightly reduced trades, but on
balance through the next week trade winds will be brisk.

Pockets of dry air rotating around the highs across the islands
are expected to will result in less than normal available moisture
as GEFS standardized anomalies show precipitable waters hovering
near 1-1.25 inches this weekend, dropping to near an inch early to
middle of next week, or half a standard deviation below normal.
The strength of the onshore and upslope flow supports showers in
windward terrain, with less coverage in downslope/leeward areas. 
The lower available moisture reduces chances of heavy rain
occurring.

Petersen