Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
232 AM EST Fri Nov 24 2023

Valid 00Z Sat Nov 25 2023 - 00Z Sat Dec 02 2023

A cold front to the north of Hawaii should help to weaken trade
winds into this weekend, bringing an increase in land/sea breezes
and showery activity. High pressure moving in to the north behind
this front should bring a brief return to moderate trade wind
activity early next week. Additional moisture should begin to be
drawn northward around the same time as well as southern stream
energy breaks off, closes off a low west of the state, and then
opens up again and advances eastward around Monday. After this
though, models are showing better agreement on a stronger and more
persistent Kona low setting up west of the state around mid week
with precipitable water values increasing up to two or more
standard deviations above normal by Thursday. The guidance
continues to show plenty of uncertainty in the exact placement of
the low, with impacts on where the heaviest rainfall sets up. At
this point, the ECMWF is closest to Hawaii with the cyclone, and
shows heavy to significant precipitation over the Islands. The CMC
is displaced farthest west, and the GFS is more in the middle of
the two and keeps the heaviest rain just to the south of the Big
Island. Regardless though, the guidance and ensembles are showing
increased potential for at least more widespread to potentially
heavy rains across Hawaii mid to later next week, with a lot of
uncertainty still in exact amounts. The guidance suggests this low
may persist into at least next weekend as well.

Santorelli