Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
827 AM EDT Mon Apr 16 2018

Valid 00Z Tue Apr 17 2018 - 00Z Tue Apr 24 2018

Drier air will move in from the northeast as a surface high slides
eastward between 30-35N. This will keep trades on the breezy side
but with mainly isolated to scattered light showers in
windward/mauka areas. Ensembles show another surge in precipitable
water values on Thursday as a weakness moves eastward to the north
of the region. The 00Z GFS/GEFS were closer to the ECMWF and its
ensembles in showing a decrease in PW values again by the weekend
into next Monday as a front pushes eastward well north of the
state, so a blended solutions was reasonable as their QPFs were
still separated higher/lower per the GFS/ECMWF, respectively. All
ensembles show increasing heights to the northwest of Hawai'i as
an upper ridge/closed high strengthens near the Dateline with
heights about +1.5 standard deviations above the mean. This will
maintain some light showers for the state.

Fracasso