Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
816 AM EDT Wed Jun 26 2019

Valid 00Z Thu Jun 27 2019 - 00Z Thu Jul 04 2019

An anomalously deep upper-level low/trough (3-4 standard
deviations below normal at 500 mb) and surface cold front that has
settled just to the northwest of the state is supporting an
ongoing risk of heavy convective rains for the western and central
islands. Radar now shows quite an active thunderstorm signature
and Flash Flood watches and advisories have already been issued by
WFO Honolulu. In this pattern, activity will be fueled by
instability and a deep moisture feed that will continue to pump
precipitable water values of upwards of 2.5 inches into the
islands into Thursday. This seems well cooroborated by latest
blend precipitable water loops. This system and threat is expected
to slowly weaken and lose influence over the islands. In the wake
of this system, a favored guidance composite shows a drying trend
over the islands with a return to a pattern with near moderate
trades and more typical windward based showers.

Schichtel