Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
822 AM EDT Tue Aug 14 2018

Valid 00Z Wed Aug 15 2018 - 00Z Wed Aug 22 2018

Surface high pressure anchored to the north of the Islands should
continue to result in breezy trades today (Tuesday), weakening by
Wednesday and through the rest of the week as the high moves east
and the pressure gradient weakens. By this weekend, models and
ensembles continue to show the potential for an easterly wave to
approach Hawaii. Both the ECMWF and the GFS are advertising
forecast PWs reaching 2+ inches which would likely increase shower
coverage across the state this weekend. At this time, models don't
show much support for particularly widespread or heavy rains, but
given the increase in both moisture and low-level easterlies
associated with the wave, would expect there to be the potential
for at least locally heavy rainfall this weekend, especially for
the Big Island and Maui.

Santorelli