Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
346 AM EDT Tue Sep 27 2022

Valid 00Z Wed Sep 28 2022 - 00Z Wed Oct 05 2022

Guidance generally shows easterly trades through the period, with
some fluctuation between light and moderate speeds depending on
the position of a couple fronts reaching close to the state from
the north along with surface high progression/evolution north of
the fronts.  Expect the trades to support windward and mountain
focused showers but sea breezes may also influence showers at
times when the background flow is on the lighter side.  There
should be a pronounced moisture gradient across the state most of
the period, with below-climatology precipitable water values over
and near the Big Island and above normal values over the
northwestern islands which will be closest to the fronts and could
see some rainfall enhancement at times.

The moisture band from the first front north of the state should
reach its closest proximity around Wednesday or Thursday (00Z GFS
a little later than the 00Z ECMWF).  The front should dissipate as
the second front approaches during the weekend and early next
week.  The GFS/ECMWF and their means have trended noticeably
farther southward with the second front compared to 24 hours ago,
now bringing the feature very close to the northwestern islands
early next week.  

Rausch