Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
821 AM EDT Sat Mar 25 2017

Valid 00Z Sun Mar 26 2017 - 00Z Sun Apr 2 2017

The upper level pattern over Hawaii for the upcoming week features
large-scale ridging centered along roughly 30 degrees north
latitude, with good agreement amongst the operational models and
their ensembles that any major systems should remain well north of
the state.  Expect a typical trade wind pattern as well through
mid-week, with some clouds and showers reaching mainly windward
and mountainous areas during that time.  The big weather maker
across the northern Pacific will be an intensifying mid-latitude
cyclone that will be originating south of Japan and forecast to
track towards the east-northeast and reaching Alaska by the end of
next week.  The implications for Hawaii will be the trailing cold
front from this cyclone, which will likely cause a break in the
subtropical ridge by Thursday night and into Friday.  This should
allow the trade winds to veer to the southeast and weaken some,
and the GFS/GEFS mean is indicating this scenario more so than the
ECMWF/EC mean.  Both of the ensemble means are not currently
indicating anything in the way of significant precipitation with
the late week pattern change, other than to enhance orographic
showers on the southeast facing terrain.

D. Hamrick