Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
707 AM EST Fri Dec 07 2018

Valid 00Z Sat Dec 08 2018 - 00Z Sat Dec 15 2018

Today's guidance again shows good agreement for the overall
forecast through the next seven days.  The front initially north
of the main islands will continue to drift southward with time and
slowly weaken, with a band of associated moisture likely to reach
down to the Big Island by Sunday.  Precipitable water values
should be somewhat below average for this time of year so expect
showers to be in the light-moderate range.  Trailing high pressure
that builds eastward along or just north of 30N latitude will
tighten the pressure gradient over the state, leading to strong
trade winds especially late weekend and early next week.  Eastward
progress of the high and a trailing cold front (forecast to remain
well north of the state) will relax the gradient a bit by
Tuesday-Wednesday but trades should still be fairly brisk. 
Another surface high will track eastward north of the state
Thursday-Friday.  Current models/means keep the gradient over the
state fairly steady during that time but some enhancement of
trades could be possible.  During next week expect precipitable
water values to remain below normal to varying degrees with light
to moderate showers favoring but not exclusively confined to
windward locales.

Rausch