Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
219 AM EDT Fri Jul 17 2020

Valid 00Z Sat Jul 18 2020 - 00Z Sat Jul 25 2020

An upper-level ridge is forecast to persist across Hawaii through
next week. Initially light trades are expected to gradually
increase over the weekend, becoming breezy. A pocket of moisture
crossing the state Saturday-Sunday may also bring some increase in
typical windward/mauka shower activity. A broad weakness in the
ridge is forecast to traverse the state from east to west next
Tuesday through Friday. The latest GEFS shows 500 hPa height
anomalies of -1 to -2 standard deviations in association with this
feature. While this should likely be associated with some increase
in instability, a somewhat drier air mass will spread across the
state during that time frame (PWs of 1.1-1.3 inch), keeping
coverage of convection limited. The mid/upper-level weakness
should push west of Hawaii by late next week, with the ridge once
again building back across the state, and continuation of breezy
trades. Overall, model/ensemble guidance showed relatively good
agreement across Hawaii through the next week, and a general model
blend is preferred.

Ryan