Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
227 AM EST Fri Dec 31 2021

Valid 00Z Sat Jan 1 2022 - 00Z Sat Jan 8 2022

The large surface high that is currently situated northeast of
Hawaii near 40N will settle southward and weaken, while a pair of
surface lows west of the state near 170W are forecast to lift
north with a convergence zone situated just north of the state. 
This zone will be the focus for enhanced rainfall through the
upcoming weekend, and both the GFS and ECMWF suggest the heaviest
rainfall should be about 100-200 miles offshore, and any deviation
south will significantly increase rainfall chances. 

By early next week, a col is expected in the subtropical ridge
axis at the surface over the western Islands, and this will tend
to lessen the trades and allow for more sea breeze based showers
through the middle of the week.  With a broad upper trough
remaining in place, the coverage of showers will likely be higher
than usual.

Hamrick