Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
209 AM EDT Tue Oct 19 2021

Valid 00Z Wed Oct 20 2021 - 00Z Wed Oct 27 2021

A col in the surface high to the north of Hawaii from a couple of
troughs/fronts is expected to remain through midweek, and then the
subtropical high should rebuild near 30-35 degrees north for the
end of the week.  Aloft, a weak upper level disturbance will
likely track westward to the south of the state late in the week. 
There is good agreement among the ECENS and GEFS means on the
evolution of the overall weather pattern with only minor
differences in magnitude of the weather features.

The features noted above are not expected to have much of an
impact in terms of rainfall, with mainly dry conditions for
leeward areas and trade wind showers for east-facing terrain. 
Although there may be some enhanced showers across the Big Island
on Sunday, the heaviest rainfall should remain well south of the
Islands.  Some abatement in the trades is likely through Wednesday
from the col in the ridge and the weakening pressure gradient, and
then increase again by next Friday/Saturday as the surface high
becomes more firmly established. 

Hamrick