Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
344 AM EDT Thu Sep 10 2020

Valid 00Z Fri Sep 11 2020 - 00Z Fri Sep 18 2020

The consensus of latest guidance maintains the persistent trade
pattern with some variation in wind speeds while below normal
precipitable water values of around 1.25 inches or lower should
favor mostly light shower activity.  Rain will focus over
windward/mountain areas most of the time but sea/land breezes that
could develop during periods of lighter trade flow, especially
this weekend, would bring some showers to other locations.  

Models and means are consistent with the expected trade wind
fluctuations in response to high pressure north of the state. 
Expect a stronger trend into early Friday followed by a weaker
trend through the weekend, and then another stronger/weaker cycle
Monday-Tuesday/Wednesday-Thursday.  Guidance still shows a fair
degree of ambiguity over specifics of flow aloft over and north of
the state next week with some influence on the strength of high
pressure.  Over recent days the consensus for mostly 1.25 inch and
lower precipitable water values has held up well, with stray
solutions having briefly higher values tending to revert back to
consensus in later runs.  Toward next Wednesday-Thursday there is
the possibility of moisture increasing in some fashion, whether
encroaching from the north as in the 12Z ECMWF mean or from the
east/southeast in the 00Z GFS/GEFS mean.  This aspect of the
forecast has very low predictability. 

Rausch