Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
714 AM EST Sat Dec 13 2014

Valid 00Z Sun Dec 14 2014 - 00Z Sun Dec 21 2014

Models show an amplified trough crossing well north of the islands
this weekend with the associated baroclinic zone gradually
shearing over Hawai`i. In its wake, building heights will allow
surface high pressure to settle to the north favoring an increase
in the northeasterly flow. During the early/middle part of next
week, the surface ridge will move east of the island chain
allowing low-level winds to veer toward more of an easterly
direction. Any meaningful height falls will continue to remain
well north of the region allowing little change in the pattern.
Looking to early next weekend, a rather potent cold front lurks
just east of the International dateline which will allow winds to
veer in response to increasing warm advection ahead of the system.

Regarding precipitation, the initial frontal boundary will spark
light shower activity given only modest precipitable water values
in place. The band of rainfall should migrate southward in time as
the boundary slowly begins to shear. Otherwise, a return to trade
wind-driven showers will become the norm throughout much of next
week with the usual upslope locations receiving the heaviest
rainfall.


Rubin-Oster