Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
348 AM EDT Fri May 26 2023

Valid 00Z Sat May 27 2023 - 00Z Sat Jun 03 2023

Latest guidance shows a western Pacific high ultimately replacing
initial high pressure north of the islands during the weekend,
followed by only gradual weakening as it drifts a bit southward. 
This combination of highs should support a general trade pattern
through the period but with some variation.  Trades should be
weakest when a surface trough passes through around Sunday, with
potential for a period of more land/sea breeze influence on
showers.  Expect trades to rebound in strength to moderate/brisk
levels by midweek, favoring a return to windward and mountain
shower focus.  Winds could slacken a bit around the end of the
week.  Initial flow around an upper trough/low northeast of the
state should lead to slightly below normal precipitable water
values over most of the islands into Saturday.  Then expect
moisture to increase to moderately above normal versus climatology
into next week with the east-west elongation of upper troughing
over/just north of the state through midweek.  This moisture may
linger for a time, with some spread developing in the guidance
regarding whether a drier trend from the northeast could commence
around Friday.  Especially over the northern islands, the 00Z
GEFS/12Z ECMWF means are slower with this trend versus the 00Z
GFS/ECMWF runs.

Rausch