Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
711 AM EST Mon Dec 10 2018

Valid 00Z Tue Dec 11 2018 - 00Z Tue Dec 18 2018

A series of surface highs tracking to the north of the state will
support strong trades over the next several days.  Showers will
favor windward terrain with some rainfall occasionally straying
over into leeward locations.  Guidance shows precipitable water
staying below climatological values through the period, which
should keep most activity in the lighter half of the spectrum. 
Weak shortwave energy passing over the state from northeast to
southwest around Tuesday may provide a little enhancement.

High pressure initially to the north-northeast should generate the
strongest trade winds early this week.  A trailing front passing
by to the north around midweek will then weaken the pressure
gradient slightly.  The next surface high reaching north of the
area late week/early weekend does not appear to tighten the
gradient but could still serve to freshen the trades for a time as
it sags southward.  A combination of rebuilding of the western
part of the surface ridge and arrival of upstream high pressure
will keep a mean surface ridge north of the area through late
Saturday or Saturday night.  By Sunday-Monday high pressure will
depart while a cold front begins to approach from the northwest,
leading to a significant weakening of the trades at that time.

Rausch