Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
354 AM EDT Sat Sep 10 2022

Valid 00Z Sun Sep 11 2022 - 00Z Sun Sep 18 2022

Light to moderate trade winds are forecast to continue through the
weekend with a weaker than normal surface pressure gradient. This
will promote a hybrid pattern of localized land/sea breezes and
trades and thus some clouds and showers possible in windward areas
but also in leeward/interior areas where sea breezes set up. The
trade winds should strengthen somewhat to moderate levels by
around Monday, causing showers to focus more in windward areas.
Model guidance remains persistent in showing a surge of deep
tropical moisture coming north toward Hawaii as early as late
Monday and shifting slowly westward through much of next week.
Less certain is how just far north the increased moisture will
reach, which varies from model to model. However, recent guidance
generally shows that while perhaps the highest moisture levels
(e.g. precipitable water values of 2+ inches) may stay south
depending on the model, at least some above average moisture is
likely to reach at least the Big Island and perhaps most of the
islands. With troughing aloft and the moist environment in place,
this could promote a wetter pattern for Hawaii centered around
Tuesday-Thursday next week, but confidence remains somewhat low,
particularly with the details.

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