Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
308 AM EST Tue Nov 17 2020

Valid 00Z Wed Nov 18 2020 - 00Z Wed Nov 25 2020

Latest models and ensembles agree that a series of surface highs
passing to the north of the state will maintain trades of varying
strength through next Tuesday.  There is good continuity/agreement
that the strongest trades will likely be during the weekend.  The
pattern will support primarily windward focused rainfall but with
sporadic episodes of showers reaching other locations as well.  A
compact upper low expected to linger southwest of Kauai through
midweek may provide some enhancement to rainfall before it
weakens/drops southward.  Most guidance has been indicating that
an area of greater deep moisture over the state (precipitable
water of 1.50 inches or greater) should progress westward after
Wednesday with the weakening of the upper low, followed by
fluctuating moisture values the rest of the period.  The 00Z GFS
is an exception to that scenario as it keeps an area of relatively
higher deep moisture over the area well beyond Wednesday.  The
GEFS mean hints at the GFS idea but with a less expansive area of
highest PWATs.  Weakening of the upper low should allow for
departure of the greatest moisture after midweek per
consensus/continuity.  However in recent days occasional cycles
exhibiting faster ECMWF moisture progression versus the GFS have
tended to be resolved in future runs by the ECMWF trending slower.

Rausch