Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
330 AM EDT Sat May 18 2024

Valid 00Z Sun May 19 2024 - 00Z Sun May 26 2024

...Heavy rain threat continues through Saturday for western
islands...

The latest guidance continues to indicate that the deep Kona low
north-northwest of Hawaii and associated surface boundary reaching
the main islands will support heavy rainfall and flash flood
threats mainly for western islands into this weekend. By early
next week, the models show good agreement the low should weaken
and lift north, but another shortwave/upper low will drop in to
the northwest of the islands behind it. This will bring moderate
east-southeasterly winds and both a windward and sea breeze focus
for showers with rainfall generally lighter than the weekend,
though the combination of PWATs staying somewhat above normal and
upper level impulses could still provide some localized
enhancement. By later in the week and into next weekend, upper
ridging and surface high pressure will build back in to the north
of Hawaii with a return to more normal trade wind pattern.

Santorelli