Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
252 AM EDT Tue Oct 20 2020

Valid 00Z Wed Oct 21 2020 - 00Z Wed Oct 28 2020

An amplified and slow moving upper low/trough to the northwest of
the state and trailing front has pulled a deep moisture plume into
the western islands. This is fueling some threat of some heavy
rain over the next couple of days in a pattern with disrupted
trades. Guidance solutions remain reasonably clustered, bolstering
forecast confidence in a composite solution. The upper low/trough
and front/moisture will gradually weaken through midweek. In this
transition, island trades would return later week into the weekend
to offer potential for tropical moisture influx into the state
from the Southeast in a pattern favoring windward terrain
rainfall. There is a growing guidance signal to then develop
another amplified upper trough/frontal system to the northwest of
the state that could again disrupt trades and renew moisture
pooling over the islands into early next week.

Schichtel