Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
259 AM EST Mon Nov 18 2019

Valid 00Z Tue Nov 19 2019 - 00Z Tue Nov 26 2019

A stationary frontal boundary across the western Hawaiian islands
is forecast to gradually dissipate over the next 1-2 days. PWs in
the 1.5 to 1.8 inch range in the vicinity of the front will
continue to favor areas of locally heavy rainfall.
Models/ensembles continue to show good agreement that an
upper-level low should drift southward toward Hawaii Mon-Tue. This
feature should enhance instability, keeping showers and a few
thunderstorms a possibility into the middle of the week, with
areas of heavy rain a possibility. After that time, models show
good consensus that upper-level ridging should begin to build
across/north of Hawaii, along with surface high pressure north of
the state. This should support the development of breezy 15-25 kt
trades and advection of somewhat drier air across the state. Thus,
expect shower activity by late in the week into early next week a
bit more confined to favored windward and mauka areas.

Ryan