Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
338 AM EDT Sat Sep 30 2023

Valid 00Z Sun Oct 01 2023 - 00Z Sun Oct 08 2023

Through the weekend, a typical Pacific surface high well northeast
of Hawaii will keep easterly trades at around moderate levels.
Weak troughing aloft and a slight surge of moisture especially
Saturday could lead to showers, which should favor windward and
mauka areas in this pattern. By around Monday and especially by
Tuesday, a pattern change is likely as a notable surface low sets
up well north and disrupts the pressure gradient over the state,
weakening winds and likely allowing for sea and land breezes to
set up. Meanwhile moisture will become limited as precipitable
water values fall below normal. This generally dry sea/land breeze
pattern is likely to last a few days. By late week, there is still
uncertainty regarding whether or not a cold front or two could
reach the state or stay to the north. The GFS/GEFS suite of
guidance generally stalls the front to the north, while the ECMWF
and  its mean show the front passing at least through the
northwestern islands with a band of moisture along/ahead of it and
northerly winds behind it. Either solution seems plausible, so
this will continue to be monitored for hopefully some model
convergence, as it will affect the sensible weather across the
state.


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