Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
718 AM EST Fri Jan 22 2016

Valid 00Z Sat Jan 23 2016 - 00Z Sat Jan 30 2016

Models and ensembles continue to show progressive mid-latitude
Pacific flow that will bring surface fronts toward and in some
cases into the islands.  Weak high pressure initially north of the
state will support light to moderate trades that will weaken as
the high moves east.  The first front of interest will cross the
area around Sun-Sun night.  There is good agreement with this
front though a more amplified than consensus mid-level trough in
the 06z GFS may have an adverse impact on its forecast.  Passage
of this front will bring a brief period of northwesterly to
northeasterly winds that will turn light/variable under a trailing
weak surface ridge.

By Tue-Wed expect winds to gain a more southerly or southwesterly
component with the next approaching front.  Then for Thu-Fri
guidance shows some spread with waviness along the front, which
lowers confidence in determining how far southeastward the front
will reach at that time.  Based on the current range of solutions
the 00z GFS has the strongest wave tracking northwest-north of the
state, with the majority cluster bringing the front a little
farther southeastward.  On the other hand by next Fri the 00z
ECMWF mean lowers mid-level heights more than other guidance so
its front might push a little too far southeastward.

Expect precipitable water values to be below climatology for most
of the period, favoring relatively light totals for any
rain/shower activity including with the Sun front.  Focus will
vary with time depending on prevailing wind direction.  For one or
two brief periods winds may slacken enough to allow for land/sea
breeze boundaries.

Rausch