Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
259 AM EST Sun Nov 15 2020

Valid 00Z Mon Nov 16 2020 - 00Z Mon Nov 23 2020

A brief period of weaker trades and some land/sea breeze influence
on showers Sunday will quickly transition to an extended period of
moderate to occasionally brisk trades with more windward rainfall
focus.  A series of surface highs to the north of the state will
support the trade flow through next weekend.  Most guidance
suggests that high pressure next weekend may be strongest so
likewise expect the best potential for the strongest trades at
that time. 

Over the past day guidance has trended into better agreement for
the particulars of the upper low expected to linger over or near
the state into midweek and provide at least some enhancement for
rainfall.  Solutions ended up gravitating more toward yesterday's
GFS/GEFS mean that advertised a far enough west track for the
upper low to keep near or above 1.50 inch precipitable water
values over the state through Wednesday--corresponding to a nearby
front remaining north of the islands.  However by Thursday model
spread returns as the 00Z ECMWF/12Z ECMWF mean go back to recent
tendencies, pushing the front/moisture farther south than the
GFS/GEFS mean.  Also after midweek the ECMWF builds somewhat
higher heights aloft over the state versus some other solutions. 
Regardless of some of these details there is the general theme in
the models/means of precipitable water varying within a range of
near to modestly above normal values late week into the weekend. 

Rausch