Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
349 AM EDT Wed Sep 13 2023

Valid 00Z Thu Sep 14 2023 - 00Z Thu Sep 21 2023

The initial trade pattern featuring moderate wind speeds and
fairly light windward focused showers will trend toward somewhat
lighter winds and increasing rainfall by the weekend.  Some
land/sea breeze influence may offer the potential for rainfall to
reach some areas away from the typical windward locations. 
Today's guidance consensus still shows above average precipitable
water values later this week through the weekend while an upper
low evolves northwest of the area and multiple surface troughs
(one from former tropical cyclone Jova) pass through during the
weekend.  One trend of note from 24 hours ago is improved guidance
convergence toward later suppression of the upper ridge initially
over the area (away from earlier GFS/GEFS runs that were quickest
to lower heights).  There is general agreement that moisture
should decrease a little early next week while trades may rebound
slightly after passage of the surface troughs and as high pressure
settles over the eastern Pacific.  This would lead to more
windward focus of showers with a decrease in rainfall totals.  The
00Z GFS/ECMWF both show an area of enhanced moisture reaching the
state around next Wednesday, originating from a tropical wave
expected to show some additional development over the coming days.
 The ensemble means are more ill-defined and/or farther south with
this moisture.  Predictability for specifics a week out is low,
but it will be worth monitoring this potential increase of
moisture over the coming days.

Rausch