Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
248 AM EST Fri Dec 06 2024

Valid 00Z Sat Dec 07 2024 - 00Z Sat Dec 14 2024

In a broad sense the guidance agrees fairly well for the pattern
through the period, though some detail differences emerge next
week.  A front with associated band of moisture should weaken
and/or retreat westward through the end of this week, followed by
a front approaching from the northwest Sunday into Monday but
likely not quite reaching the main islands.  These features will
tend to keep winds on the lighter side and somewhat variable in
direction at times, allowing for varied shower focus.  Then for
most of next week consensus shows high pressure becoming better
established north of the state, leading to a period of fairly
strong and gusty trades which may peak around Wednesday-Thursday. 
This will support more windward/mountain focus for rainfall. 
Meanwhile, guidance shows energy aloft pulling southward to the
east of the state early next week and ultimately closing off an
upper low that tracks westward along 10-15N latitude mid-late
week.  There is good agreement that this feature should increase
moisture from the southeast after midweek, likely leading to
higher rainfall totals over the Big Island in particular. 
However, the current majority cluster for the upper low track
(among both dynamical and machine learning guidance) would at
least keep the best defined band of heaviest rainfall just south
of the Big Island.  As for westward progression of the upper low,
the 00Z machine learning models generally favor an intermediate
solution like the 00Z ECMWF/12Z ECens mean (and the UKMET through
the end of its run) versus the fast 00Z GFS.  The 00Z CMC/CMCens
mean are a bit on the slower side.

Rausch