Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
257 AM EST Mon Mar 04 2024

Valid 00Z Tue Mar 05 2024 - 00Z Tue Mar 12 2024

Today's guidance continues to show a fairly wet trade regime
through the period with an upper trough over/near the region
helping to enhance shower activity at times.  One surface high
will track north of the state early-mid week to support brisk
trades, with a second one settling to the north potentially
leading to stronger winds around Friday-Saturday.  Gradual
weakening of this high into early next week should help to weaken
the trades somewhat by then, but still remaining on the brisk
side.  Heaviest rainfall should be early this week as upper level
energy beginning to settle into place enhances deep moisture the
most.  There is still notable spread in the guidance for moisture
levels during the rest of the period, likely due in part to
low-predictability differences in details aloft, but the envelope
has narrowed somewhat over the past day.  Recently high
precipitable water values in the GFS have nudged down a bit
(though remaining on the wetter side) while the ECMWF, generally
quickest to trend drier over recent days, has delayed its drier
trend to some degree.  The GEFS/ECens means are between the
extremes.  An intermediate consensus would maintain moderately
above normal PWATs through about Thursday, especially over the
southeastern two-thirds of the main islands, with a gradually
drier trend by Friday-Monday.  It is worth noting that the
GFS/GEFS/CMC are suggesting that an upper low could become better
defined again just west-southwest of the state by next Monday and
PWATs at that time may be sensitive to the upper low position, so
confidence in the moisture forecast by then is fairly low.

Rausch