Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
716 AM EDT Fri Aug 04 2017

Valid 00Z Sat Aug 05 2017 - 00Z Sat Aug 12 2017

It remains the case that the central Pacific still features an
upper low over the mid-latitudes well to the north of Hawai'i.
Eventually this circulation is forecast to lift toward the
Aleutians and be of minimal consequence to the Hawai`ian island
chain. Closer to the region of interest, an upper low spins
near/just east of the International Dateline while broad ridging
extends to the east of Hawai`i. By the middle-later part of next
week, there's a hint of further amplification in the
mid-latitudes. However, only the GFS/GEFS mean continue to show
this which appears to be somewhat outlying based on ensemble
spaghetti member comparisons.

At the surface, a strengthening in the dome of high pressure to
the north will lead to an uptick in the trades today into the
weekend. The strength of these winds may come down a bit early
next week as the surface pressure gradients begin to show marginal
weakening. Regarding threats for precipitation, the better
moisture fluxes should stay to the south of the islands based on
the precipitable water forecast. However, given the moderate
trades noted in the guidance, expect a potential increase in the
coverage of windward showers today into the weekend.

Schichtel