Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
840 AM EDT Mon Sep 21 2015

Valid 00Z Tue Sep 22 2015 - 00Z Tue Sep 29 2015

Models and ensembles reasonably agree upon the overall flow
pattern across the Hawaiian Islands for much of the next week.
High pressure northeast of the state and moderate to fresh trades
underneath over the state should combine with pooling moisture to
favor windward showers in the short term, with best downpour
potential from Molokai and Maui to the Big Island where a flash
flood watch is now in effect as per WFO Honolulu. A closed low now
spinning aloft to the northeast of the state will continue to lose
remaining island weather influence as a new Pacific high will
strongly reforms and reinforces north of the islands mid-late week
and beyond in the wake of ample eastern Pacific trough/low
amplification. Moderate to locally brisk island trades may relax
some during the transition and then rapidly rejuvinate...leading
to potential for additional enhanced rainfall with increased
moisture availability around Sunday/Monday, with best potential
over the Big Island.

Schichtel