Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
326 AM EST Tue Dec 28 2021

Valid 00Z Wed Dec 29 2021 - 00Z Wed Jan 05 2022

A persistent and anomalously strong high pressure, located between
Hawaii and Alaska, will remain anchored in the North Pacific for
several days more before weakening and shifting southward by the
coming weekend. Additionally, there will a closed upper low
meandering west of Hawaii as it is blocked within the flow
pattern, but as the ridge weakens later in the forecast it should
drop south. In the meantime, gusty trade winds are expected to
continue through the week with showers tending to favor the
typical windward facing terrain. Models are showing an amplifying
upper trough to move into the region west of the state, which will
drive a cold front towards the western islands causing the winds
to become more south or southeasterly. This in turn will allow a
plume of moisture to transport toward Hawaii by the end of the
week/weekend. Widespread and moderate to locally heavy rainfall
across at least parts of the island chain next weekend.

Campbell