Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
830 AM EDT Sun Sep 22 2019

Valid 00Z Mon Sep 23 2019 - 00Z Mon Sep 30 2019

An upper-level low currently drift into the western outer islands
of Hawaii westward will continue to move west-northwest while
bringing a stream of tropical moisture northward across the main
islands of Hawaii from east to west through this week.  The
moisture axis is expected to move slowly across the main islands
during the next few days before becoming nearly stationary over
the western islands for the rest of the week.  This will likely
result in more numerous showers across the eastern islands
followed by periods of heavy rain possible over the western
islands by midweek.  A high pressure ridge at the lower levels
should slowly push drier air from east to west across the islands
through late next week into the weekend with decreasing rain
chances as trade winds strengthen.  However, available moisture is
forecast to remain above normal.  As a mid-level upper low drifts
northwestward to the east and northeast of Hawaii, higher
instability would increase the chance of thunderstorms across the
area.

Kong