Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
800 AM EDT Sun Apr 09 2017

Valid 00Z Mon Apr 10 2017 - 00Z Mon Apr 17 2017

The next week will overall feature an increase in pooling moisture
content across the state, as a ridge of high pressure loses its
grasp and an upstream short wave within the westerlies approaches.
This short wave is currently positioned just upstream, south of
30N and between 170-180W. The bulk of upper dynamics with this
feature will shear downstream north of the islands but a batch in
the base will relocate to just west of the state. This weakness
will be relatively stationary west or northwest of the islands,
not quite a cut-off/Kona low, before becoming extremely positively
tilted and attempting to advance east or through the state. Now
despite all this activity aloft, it appears the main surface
front/boundary will remain north of the state. However, the
lowering of heights and increasing southwesterly component should
allow the 1 inch or greater precipitable water moisture content to
produce shower activity across the entire state. The 06z gfs shows
much more of a signal of showers/rain Tues-Thurs than the 00z
ecmwf, with the moisture plume directed at Kauai/Oahu and
eventually Lanai/Molokai/Maui. Its tough to discern which model is
correct at the moment but given the overall pattern setup, the
operational gfs may be onto something which would keep the state
unsettled for a good part of the work week.

Musher