Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
349 AM EDT Mon Aug 07 2023

Valid 00Z Tue Aug 08 2023 - 00Z Tue Aug 15 2023

Latest guidance is consistent in showing a period of very strong
and gusty winds that should peak around Tuesday, due to the
combined westward progression of a deep-layer ridge to the north
and Hurricane Dora tracking to the south along 10-15N latitude. 
Weakening and continued westward motion of these features should
allow winds to decrease starting on Wednesday and settle into the
moderate range late week into early next week.  Models/means
continue to show an upper trough and possibly an embedded low
dropping into the area from the northeast by the weekend, and this
feature may serve to weaken the trades as well.  Specific details
aloft remain ambiguous, but today there is a greater guidance
majority that brings at least some of this energy to the islands
by Sunday.  At that time the 00Z ECMWF/CMC/CMC mean and 12Z ECMWF
mean all suggest that the surface pressure gradient over the
region could be somewhat weaker than advertised by the 00Z
GFS/GEFS mean.  Models and means continue to advertise an
unusually dry period from Tuesday onward.  Below-climatology
precipitable water values may reach as low as minus 2-2.5 or so
standard deviations Tuesday-Wednesday, followed by somewhat less
extreme values but likely staying drier than average by at least
one standard deviation into the start of next week.  The upper
trough/low reaching the area late in the period could slightly
increase what rainfall occurs in generally windward focused
showers.

Rausch