Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
359 AM EDT Sun Oct 30 2022

Valid 00Z Mon Oct 31 2022 - 00Z Mon Nov 07 2022

Current guidance shows a gradual oscillation of trades over the
course of the week.  Expect moderate winds from now through
Tuesday as an upper low to the northeast of the state dents the
pressure gradient to the south of a mid-latitude surface high. 
Consensus still shows a trend to more brisk winds mid-late week as
a stronger surface high settles over the east-central Pacific. 
Most guidance shows a weakening and more southeasterly tilt of the
trades over the course of next weekend as the surface high weakens
and a front comes into the picture off to the west.  Note that
during next weekend the 00Z GFS strays to the western side of the
spread for the overall upper trough-ridge pattern over the central
Pacific, so an average of the 00Z ECMWF/CMC and GEFS/12Z ECMWF
means would be preferable for depicting the upper pattern and
surface response.

Typically windward/mountain-focused showers should be lightest
during the first part of the week as guidance maintains below
average precipitable water values over most of the state, perhaps
aside from the Big Island.  With typical detail differences,
guidance maintains its signal for moisture to increase from the
east during the latter half of the week.  Also an upper level
weakness should develop over the area as a strong ridge prevails
to the north, and there could be an embedded upper low that tracks
near the islands.  The combination of moisture and upper level
evolution should lead to higher trends for rainfall amounts.  By
next weekend the rainfall focus could shift more to
southeast-facing terrain, and/or other locations depending on how
pronounced the lighter and southeasterly trends become.

Rausch