Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
247 AM EST Fri Jan 03 2020

Valid 00Z Sat Jan 04 2020 - 00Z Sat Jan 11 2020

Expect breezy to locally windy trades through most of the period
as high pressure dominates at mid-latitudes.  One surface high
initially north of the area will head into the eastern Pacific by
Sunday-Monday and then another high will build around 30-40N
140-150W, coincident with a building ridge aloft.  These surface
highs will maintain a strong gradient over the state.  Meanwhile
guidance agrees that an upper low will form east of the state
during the weekend and persist through much of next week.  Some
elongation should occur with time in response to the upper ridge
that builds to the north.

The strong trades will likely focus showers over windward/mountain
areas though some rain could stray to other locations at times. 
By mid-late week the 00Z ECMWF becomes quicker to bring lower
heights aloft/lower surface pressures as well as moisture across
the region from east to west versus most other guidance, including
the 12Z ECMWF mean.  This relation to other guidance and the
model's historical tendency of occasionally being too aggressive
with flow retrograding beneath an upper high would favor leaning
mostly away from the ECMWF specifics for now.  The GFS/GEFS mean
and 12Z ECMWF mean do bring increased moisture in from the east
but only around or just after the end of the forecast period next
Friday.

Rausch