Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
248 AM EST Sat Nov 14 2020

Valid 00Z Sun Nov 15 2020 - 00Z Sun Nov 22 2020

Guidance is similar and consistent early in the period, showing an
upper low/weakness settling over the state by Sunday.  This
feature will help to weaken the trades somewhat and allow for
potential land/sea breeze influence on rainfall which should
increase in coverage/intensity with the arrival of greater deep
moisture--especially over and near the the Big Island.  After the
weekend there is a general consensus toward a moist trade pattern
with primarily windward-focused rainfall through the end of the
forecast period.  One or more fronts should approach from the
north with trailing high pressure helping to maintain the trades. 
However models and means differ significantly among each other
(and from yesterday's continuity in some cases) for the exact
evolution and position of the upper feature, affecting the timing
and southward extent of a front around midweek.  The 00Z GFS/GEFS
mean are on the western side of the envelope with the upper
feature thus leading to less southward progression of the front
and greater extent/duration of higher precipitable water values. 
Remaining guidance suggests the 00Z ECMWF could be a little
extreme on the other side of the spectrum, ultimately favoring an
intermediate solution at this time.  The low predictability
typically associated with an upper feature of relatively small
scale also recommends a conservative approach well within the
overall guidance envelope.

Rausch