Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
215 AM EDT Mon May 11 2020

Valid 00Z Tue May 12 2020 - 00Z Tue May 19 2020

Models/ensembles show good consensus that a mid/upper-level ridge
should remain in place across Hawaii and much of the Central
Pacific through the next week. Moderate trades are expected
initially as surface high pressure slides eastward north of the
state, keeping windward/mauka showers in place. A weakening
upper-level disturbance embedded within the ridge may bring a
brief increase in shower activity through Tue, before drier air
works into the state later this week. Model guidance shows general
agreement on this feature as well as a relatively modest increase
in PW values across Hawaii in the vicinity of the upper low.
Trades should weaken by midweek as high pressure spreads south
across Hawaii and weakens. As a stronger surface high develops
north of the state once again by the weekend, trades should
return. Ensemble means show good consensus (ECENS/GEFS/NAEFS) that
the upper ridge in the vicinity of Hawaii should strengthen by
next weekend, with ensemble means showing the center of the upper
ridge anchored directly over Hawaii by Sun. This should serve to
keep convection relatively suppressed by that time, with isolated
showers sticking to favored windward/mauka locations.

Ryan