Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
259 AM EST Wed Nov 30 2022

Valid 00Z Thu Dec 01 2022 - 00Z Thu Dec 08 2022

Latest guidance finally appears to have stabilized for the portion
of the forecast covering the latter half of this week through the
weekend.  During this time frame expect a lighter trend for
showers as drier air moves into the region from the
north/northeast, a scenario that the models/means had trended
toward 24 hours or so ago.  Meanwhile high pressure well to the
northeast should extend its influence just enough to transition
winds from northerly or northeasterly initially to moderate
easterly trades by Friday and continuing through the weekend. 
This will provide a windward/mountain focus for any showers that
occur.

Then by Monday-Wednesday, individual models and ensemble members
diverge wildly for the ultimate evolution of energy within a
sharpening upper trough that approaches from the northwest to
start the week, leading to similarly wide spread for the surface
pattern and moisture/precipitation distribution.  On one extreme
the 00Z ECMWF and a decent cluster of 00Z CMCens members pull off
an upper low to the west of this islands.  The ECMWF solution
leads to a moister pattern with southeasterly winds but the upper
feature in the CMC mean is weak enough for fairly brisk trades to
persist.  On the other hand, the latest GFS runs and 00Z CMC close
their upper low to the northeast of the state and ultimately
develop strong northeasterly winds, with at least the GFS showing
a significant drying trend by Tuesday-Wednesday after a modest
rebound in moisture around Sunday-Monday as a front approaches. 
The 00Z GEFS/12Z ECMWF means are similar in showing this modest
moisture rebound at the start of the week and a brief weakening of
the trades with the front, followed by some re-establishment of
trades and windward shower focus (more so in the ECMWF mean since
it has less upper troughing to the northeast than the GEFS mean). 
Some individual GEFS/ECens members still vary a lot though. 
Relative to other guidance the GFS winds become rather strong by
midweek.  Based on the full array of guidance, would favor a
solution closest to the GEFS/ECMWF means in principle while
waiting for better model agreement.

Rausch