Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
806 AM EDT Sat Apr 13 2019

Valid 00Z Sun Apr 14 2019 - 00Z Sun Apr 21 2019

An upper-level low situated east of Hawaii early this morning is
expected to persist into early next week before moving eastward
away from the state. Models/ensembles show broad agreement on this
evolution, with relatively minor differences primarily in the
depth of the feature. At the surface strong high pressure anchored
well northeast of the state is expected to keep moderate trades in
place into early next week, before these begin to relax by midweek
as the surface high weakens and moves east. The combination of the
upper low generating enhanced instability along with some degree
of deeper moisture pooling will be sufficient to produce scattered
showers and even a few thunderstorms, which should focus primarily
across windward locations in eastern portions of the state. Areas
of locally heavy rainfall will be possible, and ECENS
probabilities continue show the greatest potential for heavy rains
across eastern portions of the Big Island through Sunday.

By the middle of next week, as the upper low moves east, light to
moderate trades are expected to continue with more isolated
windward shower activity. Any influence from a fairly active
frontal zone across the north central Pacific appears likely to
remain north of Hawaii through late next week.

Ryan