Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
649 AM EST Wed Feb 17 2016

Valid 00Z Thu Feb 18 2016 - 00Z Thu Feb 25 2016

Fairly quiet rest of the week for Hawai'i with generally light
windward showers and northeast breezes veering to easterly later
this week. Some showers spill over to leeside areas thanks to
stronger trades than normal. By the weekend into next week,
ensembles still show good agreement on strong upper ridging
retrograding westward past the Dateline and expanding northward
which will allow troughing to dig right toward Hawai'i. A wave of
low pressure may form along the front north of the islands Sat
nigh-early Sunday, which would keep the bulk of the precipitation
to the north and east of the region, per the ensembles. The 00Z
GFS forecasts the more amplified solution with the GEFS
mean/operational ecmwf/ecmwf ensemble mean/Canadian global
slightly less amplified with the 50 mb trough Sun-Mon.  The models
are in agreement the upper trough moves east of the islands Mon
night-Tue 23 Feb 00Z ECMWF was just a bit slower than the
multi-center ensemble mean.
A low level ridge builds in west of Hawaii early-mid next week,
low level flow becomes light over the state with only light,
sparse shower activity expected as the GEFS precipitable water
anomalies persist with values 1-2 standard deviations below
normal.


Petersen