Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
801 AM EDT Mon Jul 17 2017

Valid 00Z Tue Jul 18 2017 - 00Z Tue Jul 25 2017

Initially, an elongated positively-tilted upper trough over the
Hawai`ian island chain will drift west-southwestward to move west
of the islands through mid week. An upper ridge moves across the
islands later in the week, and then west of the islands next
weekend.  At the surface, a persistent anticyclone will remain
north of the islands this week. This favors the persistence of
trade winds across the region, generally in the 15 to 20 knot
range.
Showers are forecast across the Big Island as well as windward
locations of the other islands.

Next weekend, an inverted trough, with a low level tropical wave
associated with the remnants of Fernanda, is forecast to possibly
approach from the east. Enhanced tropical moisture will move
across the islands late next weekend into early next week, so the
tropical wave might produce enhanced shower activity with
potential for locally heavy rain. The models continue to show
timing differences so the peak period of rain remains uncertain.

Petersen