Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
212 AM EST Sun Dec 04 2022

Valid 00Z Mon Dec 05 2022 - 00Z Mon Dec 12 2022

...Kona low development just northwest of the state favors a
early-midweek heavy rain threat...

Recent and latest runs of the GFS/ECMWF/UKMET/Canadian agree that
shower activity across Hawaii should be relatively limited through
the weekend under general upper ridging. Expect moderating
easterly trades will support some windward/mountain focused
showers.

The aforementioned models and supportive ensembles offer a similar
pattern evolution for the coming week, bolstering forecast
confidence. There is a strong signal to carve out a kona low to
settle just to the northwest of the islands early week to linger
into midweek before ejecting northwestward away from the state.
This would stall a well defined surface front just west of the
islands early week and lead to a shift to southeasterly/southerly
winds into the islands with increasingly deep and sustained
moisture inflow. This may fuel a protracted period favorable for
some heavy downpours that may lead to local runoff issues.

High pressure building strongly in guidance to the northeast of
the state in the wake of closed lo departure later week into next
weekend should then support a return to more typical moderate to
breezy easterly trades and revert to a pattern with more limited
moisture and windward terrain focusing showers under a rebuilding
upper ridge.
 
Schichtel