Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
826 AM EDT Wed Jun 21 2017

Valid 00Z Thu Jun 22 2017 - 00Z Thu Jun 29 2017

A surface frontal boundary about 400 miles to the northwest of the
islands is forecast to remain away from the region as the low
pressure moves to the northeast. High pressure south of the
Aleutians will slide eastward along 44N and maintain moderate
trades (especially to the north) thanks to the pressure gradient
between the 1033-34 mb high and sub-1016mb pressures over Hawai'i.
Trades may increase more next week as the high slips southeastward
to 40N. Deep moisture should remain well south of the area so
generally light windward showers are expected. Aloft, the upper
high will center near 170E which favors weak troughing over the
50th state. Ensembles indicate a drop in precipitable water values
next week suggesting a lower chance of rain which was shown
explicitly from the latest GFS/ECMWF forecasts.


Fracasso