Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
202 AM EST Thu Dec 17 2020

Valid 00Z Fri Dec 18 2020 - 00Z Fri Dec 25 2020

...Wet Pattern for the next few days...

A favored composite of overall compatible model and ensemble
guidance shows strengthened trades for the next few days as high
pressure bridges to the north and settles to the northeast of the
state. This pattern brings an increasing chance to tap deeper
tropical moisture to fuel showers and thunderstorms as upper
troughing works over the islands, especially eastern Maui and the
Big Island. Heavier downpours offer a runoff threat and a Flood
Advisory has been issued for windward areas of the Big Island
where locally heavy rains are ongoing. Deepest moisture may linger
over the Big Island this weekend, but there is a decent guidance
signal to bring stabilizing upper ridging over the state into next
week in drier flow. Looking forward, there is a good guidance
signal to amplify the mid-upper latitude flow over the Pacific
heading into the Christmas holidays that could force a decent cold
front to the northwest of the islands, but Hawaii still seems
shielded by upper ridging.

Schichtel