Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
345 AM EDT Sun Jun 12 2022

Valid 00Z Mon Jun 13 2022 - 00Z Mon Jun 20 2022

The most consistent part of the forecast is the expected surface
pattern that should help to maintain mostly moderate to brisk
trades through next weekend.  Models/means continue to show an
evolution that involves an initial surface high tracking westward
to a position north of the state along 30N latitude by Monday,
then quickly giving way to a stronger central Pacific high that
passes by to the north along 35-40N Tuesday-Wednesday and
ultimately settles well northeast of the state.  Most showers
should focus over windward/mountain areas, though some moisture
could stray to other locales at times.   

As for other details, consensus shows below normal precipitable
water values persisting through Tuesday and helping to keep
showers on the light side early in the week.  An area of enhanced
moisture originally from an old front should pass through from the
northeast around Wednesday (possibly into early Thursday), leading
to some enhancement of showers.  In recent days the best signal
had been for the greatest moisture to cross the northwestern
islands but now the 00Z ECMWF/ECMWF mean show a little more
southward extent.  Behind this pocket of moisture, today's
guidance has settled into better agreement on an upper
trough/compact low crossing the state after midweek and centered
just northwest of the main islands by Friday.  Most models/means
show a broader weakness aloft developing over and northwest of the
state during the weekend (with the upper low still in the picture)
while precipitable water values settle to within a half standard
deviation on either side of normal.  These ingredients should lead
to a slightly drier pattern than expected around the middle of the
week but a somewhat wetter one than forecast early this week.

Rausch