Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
252 AM EST Sun Mar 03 2024

Valid 00Z Mon Mar 04 2024 - 00Z Mon Mar 11 2024

Today's guidance continues to show brisk to strong trades for most
of the period, with one surface high tracking north of the islands
helping to bump up wind speeds early this week and followed by
second late-week high that could tighten the gradient even more
around Friday-Saturday before slackening a bit by Sunday.  This
pattern will maintain windward/mountain rainfall emphasis.  The
forecast remains on track with the early part of this week having
the best heavy rainfall potential as upper troughing and possible
embedded low settle over the area while enhanced moisture lifts
northwestward into the Big Island and vicinity.  Through the rest
of the week into next weekend, models and ensembles have been
inconsistent with precipitable water trends in response to minor
differences in position and strength of the upper feature that
lingers over the state.  The latest ECMWF/ECMWF mean depict a
fairly pronounced drier trend, with precipitable water values
reaching near or under one inch by next weekend.  In contrast the
00Z GFS actually shows a rebound in moisture during the latter
half of the week and lingering into the weekend due to a slightly
stronger and northwestern upper trough/low.  The 00Z GEFS mean
(declining to 1-1.25 inch PWATs) shows a gradual drier trend but
not quite to the degree of the ECMWF/ECMWF mean.  Relatively low
predictability of exact details of the upper feature several days
out in time, along with oscillating multi-day trends in some
guidance, ultimately favor an intermediate solution for moisture
and rainfall potential from midweek through next weekend.

Rausch