Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
332 AM EDT Sun Apr 27 2025

Valid 00Z Mon 28 Apr 2025 - 00Z Mon 05 May 2025

Today's guidance shows good continuity with the overall pattern
through the period. Sunday-Tuesday will be unsettled with a
surface trough and band of enhanced moisture aligned over the main
islands, supporting episodes of locally heavy rainfall (possibly
with some thunder) that should have a sea/land breeze focus due to
light winds. Consensus still shows an upper low closing off north
of the state on Monday and diving south over or barely northeast
of the main islands on Tuesday before continuing eastward and
opening up. This upper low would enhance instability as it passes
through.

Departure of the upper low and then surface high pressure
tracking by to the north will bring a return of trades from
midweek onward. Winds may become fairly brisk late week through
the weekend, with a decent gradient persisting into Sunday even as
high pressure settles over the eastern Pacific. The trade pattern
will support windward/mountain focus for showers that should
trend lighter, given precipitable water values declining to or
below climatology.

Rausch