Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
337 AM EDT Fri Jun 26 2020

Valid 00Z Sat Jun 27 2020 - 00Z Sat Jul 04 2020

Today's guidance agrees on maintaining trade flow but with some
variability in wind speeds during the period, along with generally
light rainfall that should have greater focus over
windward/mountain areas.  Moderate to brisk trades late this week
should trend lighter during the weekend (especially Sunday) as an
upper low tracking well northeast/north of the state brings an
upper weakness and a possible surface trough across the area.  The
upper weakness/surface trough could provide modest enhancement to
rainfall and temporarily reduce the windward focus somewhat.  Then
by Tuesday-Wednesday expect the pressure gradient to tighten and
trades increase as an upper ridge moves in from the
east/northeast.  Later in the week the models begin to differ over
how quickly the upper ridge weakens/progresses westward, with some
influence on the trades.  The 00Z GFS/GEFS mean are the quickest
with the weakening/progression and thus lead to gradually lighter
trades.  On the other hand the 00Z CMC holds onto its upper ridge
through next Friday.  An average of the 00Z ECMWF/00Z CMC mean/12Z
ECMWF mean provides the best intermediate solution for this part
of the forecast. 

Rausch