Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
258 AM EST Fri Dec 22 2023

Valid 00Z Sat Dec 23 2023 - 00Z Sat Dec 30 2023

Expect a drier trend after late this week, as an upper ridge
building across the area from the west during the weekend into
next Monday pushes an initial trough and associated moisture
southeastward.  A surface ridge north of the state will support
moderate trades through the weekend.  Then a front passing through
around Monday-Monday night will disrupt the trades, with trailing
high pressure bringing a brief period of brisk northerly flow on
Tuesday followed by lighter trades Wednesday.  What little
moisture accompanies this front may hang up near the Big Island
through at least midweek.  The next Pacific system in the series
that further erodes the early week upper ridge shows more spread
in the guidance for amplitude aloft and southward extent of the
cold front.  Currently the 00Z GFS is the most amplified solution
aloft and thus pushes the front all the way through the main
islands by Friday.  Most other guidance (including the 18Z GFS,
00Z ECMWF/12Z ECMWF mean, and 00Z GEFS mean) indicates that this
late week front may barely reach the northwestern islands.  This
latter more likely scenario would lead to some lighter and more
variable winds over the main islands late in the week versus the
brief episode of strong northerly winds forecast by the 00Z GFS
behind its front.      

Rausch