Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
248 AM EST Wed Dec 27 2023

Valid 00Z Thu Dec 28 2023 - 00Z Thu Jan 04 2024

Latest models and ensembles continue the theme of multiple fronts
that may affect the state to varying degrees and lead to
day-to-day variability in winds and shower focus.  Most of the
period will feature below-climatology precipitable water values,
keeping rainfall totals on the lighter side.  Looking at the
details, an initial band of moisture over the southern islands
should dissipate while a front drops over the state
Thursday-Friday.  Recent model trends for the late week front have
been a little southward by Friday with the associated band of
moisture settling over the Big Island into the weekend.  Another
front should reach a position north of the state on Saturday, with
GFS runs incrementally trending north toward other solutions.  The
GFS is still a little extreme with its amplitude of supporting
shortwave dynamics but not to the extent seen in prior days.  Then
there are still some small scale/low predictability shortwave
issues that affect details of the next front forecast to arrive
early next week.  Today the 00Z CMC is the only solution (and thus
not favored) that still pulls off a sharp upper trough/low just
west of the main islands to keep the front to the north.  The
00Z/18Z GFS and 00Z ECMWF pull off some weak energy over or just
east of the state so there is still the potential for the front to
stall once it reaches the islands, with specifics aloft affecting
how much moisture lingers over the area into midweek.

Rausch