Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
222 AM EST Tue Dec 24 2024

Valid 00Z Wed Dec 25 2024 - 00Z Wed Jan 01 2025

The model guidance agrees well that the subtropical ridge will
strengthen near and north/northeast of Hawai'i into Friday,
resuming trade winds.  The base of a progressive trough will split
the warm core ridge in two from late Friday onward, as an upper
level low cuts off east to southeast of the Big Island, causing
some relaxation in the low-level wind flow as a front/shear line
moves into the main islands Friday into Saturday which should
briefly provide a focus for moderate to possibly heavy rain
showers Saturday into Sunday before the boundary fades.  Its
fading will be coincident with a resumption of trade winds as
ridging rebuilds somewhat to the north, moreso at the surface than
aloft.

Roth