Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
111 AM EDT Thu Jun 18 2020

Valid 00Z Fri Jun 19 2020 - 00Z Fri Jun 26 2020

A relatively quiet weather pattern appears likely to persist
across Hawaii. High pressure at the surface and aloft is forecast
by all guidance to remain anchored north of Hawaii, keeping a
breezy trade wind pattern in place, with scattered, primarily
windward showers. Models continue to show a relatively weak
easterly wave traversing Hawaii, moving west of Hawaii by late
this week. A relatively dry air mass in place (PWs ranging from
1.0-1.5 in.) should keep any associated activity somewhat sparse,
and limit the potential for any heavy rains. Guidance shows
general consensus that as the system moves west of Hawaii, it
should cut off, and perhaps become nearly stationary for a period
of time, before  perhaps once again slowly drifting farther west
by later next week. The implications for sensible weather across
Hawaii of this seem relatively minor - perhaps a slight weakening
of the trades early Sun-Mon. Deterministic guidance continued to
show some variability on the handling of the upper low, but
ensembles continued to show relatively good agreement, so favor an
approach to the forecast heavily reliant on ensemble means with
respect to that feature into next week.

Ryan