Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
358 AM EDT Sat Nov 02 2024

Valid 00Z Sun Nov 03 2024 - 00Z Sun Nov 10 2024

Today's models and ensembles agree fairly well up to about the
middle of next week and then diverge for details at the surface
and aloft.  Continue to expect moderate trades and
windward/mountain shower focus through the weekend into early next
week, supported by high pressure well to the northeast of the
state.  Consensus still shows weak shortwave energy approaching
from the west and enhanced moisture arriving from the
east-southeast combining to support some locally heavy rainfall
around next Monday-Tuesday with particular emphasis over the Big
Island.  Then a front should progress close to or into the main
islands from the northwest around midweek while the southern
periphery of the supporting upper trough starts to drop southward.
There are various ideas for what this upper energy will do, but
the 00Z ECMWF is the most extreme in closing off an upper low that
settles over the main islands by next Saturday.  This evolution
aloft leads to a significant break in trades due to surface
troughing (with a surface low to the north).  Remaining dynamical
guidance says that this energy should be either farther east or
south, while the latest machine learning models favor southward
suppression of energy as the upper ridge bridges eastward with an
axis just north of the state.  The majority scenario favors
continuity that reflects establishment of brisk northeasterly
winds after midweek, perhaps turning more easterly by next
Saturday.  Moisture should trend down to near or slightly below
climatology after midweek, with rainfall totals likewise trending
down somewhat compared to earlier in the week.

Rausch