Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
822 AM EDT Mon Aug 14 2017

Valid 00Z Tue Aug 15 2017 - 00Z Tue Aug 22 2017

Moderate to breezy trades will slowly subside after Wednesday as a
strong upper/sfc high
currently to the north of the area moves northeastward. This will
allow a weakness aloft to move westward to the north of Hawai'i
with little influence. Precipitable water and low/mid-level
relative humidity values are forecast to remain below average for
this time of year through Saturday before starting to increase
next Sunday and especially Monday. By then, the 06Z GEFS indicate
about a 50-60% chance that precipitable water values will be at
least +1 standard deviations as moisture pushes westward. The 00Z
ECMWF was rather aggressive (sometimes showing the highest PW
value of any ensemble member) compared to the rest of the
multi-center ensemble guidance so preferred a solution closer to
the GFS for now. This would indicate only a slight increase in
trade wind showers after a rather quiet work week.


Fracasso