Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
817 AM EDT Tue Jul 30 2019

Valid 00Z Wed Jul 31 2019 - 00Z Wed Aug 07 2019

...Erick forecast to move south of Hawai'i late this week...
...Flossie expected to approach Hawai'i first half of next week...

The most prominent aspect of the forecast will be the potential
effects from two tropical systems.  Based on the latest Central
Pacific Hurricane Center advisory, Hurricane Erick will strengthen
further over the next couple days and then weaken to a tropical
storm as it passes to the south of the main islands Thursday night
into Saturday.  This system will bring the potential for areas of
heavy rainfall and enhanced winds/waves, with specifics very
sensitive to the exact track.  Based on current guidance there is
reasonable consensus that the Big Island should see the heaviest
rainfall in association with Erick.  Farther east is Tropical
Storm Flossie, which based on the latest National Hurricane Center
forecast should reach hurricane status soon and approach the main
islands in the Monday-Tuesday time frame.  As is typical for days
6-7 forecasts there is a fair amount of spread for track/timing,
but there is a common theme of a track somewhat farther north than
with Erick.  Again the exact track of Flossie will determine
location/magnitude of effects from heavy rainfall, strong winds,
and high waves.

Otherwise, through midweek expect moderate to brisk trades
supported by central Pacific high pressure, and windward/mountain
showers that may be enhanced by a pocket of deep moisture passing
through the region along with a weakness aloft.  Between Erick and
Flossie there will be some lingering moisture to promote
occasional showers.  However trades will likely not be as strong
as early in the period as energy dropping from the Bering Sea into
the east-central Pacific erodes the mid-latitude high pressure.

Rausch