Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
329 AM EDT Sun Oct 01 2023

Valid 00Z Mon Oct 02 2023 - 00Z Mon Oct 09 2023

Another day of fairly typical trade wind weather is forecast for
Sunday. Compared to Saturday there may be fewer showers as
moisture levels decrease, but a weak low aloft should provide some
continued instability. Showers that form should favor windward and
mauka areas. However, by around Monday and especially by Tuesday,
a pattern change is likely as a notable surface low sets up well
north and its associated front hovers north of the islands,
disrupting the pressure gradient over the state. This will weaken
winds and likely allow 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 the latter half of the week, there is still uncertainty
regarding whether or not the front could reach the state. Recent
model guidance is suggesting the front could reach the
northwestern islands with a band of moisture along/ahead of it by
around Thursday and then dissipating there. By late week a surface
high is forecast to form northwest of the state, with its pressure
gradient sufficient to reform easterly trades. There may be
another chance at a front to approach early next week, which will
continue to be monitored.

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