Forecast: Humid, with a chance of heavy rain for Kauai and maybe Oahu

Forecast: Humid, with a chance of heavy rain for Kauai and maybe Oahu
Radar shows a line of heavy showers from a cold front over Kauai and Niihau. (Source: Hawaii News Now)

HONOLULU, Hawaii (HawaiiNewsNow) - A stalled cold front is bringing very wet weather to Kauai County, which is under a flash flood watch through Sunday afternoon. Heavy rain and thunderstorms from the south are expected to move over the Garden Isle and Niihau, especially tonight.

An upper low pressure system has parked itself about a thousand miles to the northwest of the state, which is adding to the unstable conditions. Showers will be possible on Oahu, but if the upper level nudges southward, the island could also see a higher threat of heavy rain and isolated thunderstorms.

Somewhat quieter conditions are expected for Maui County and Hawaii island, but there will be a chance for afternoon pop-up showers due to the light winds.

Looking a bit further ahead into next week, the front should dissipate and the upper low should pull away to the north sometime Monday, bringing gradually improving conditions. However, it will still be muggy with light winds because we could get another front approaching from the northwest that will keep the trade winds away.

At the beach, the northwest swell from gale force winds associated with the frontal system has come in larger than expected, just high surf advisory levels. Surf will be larger for the north and west shores of Kauai and Oahu; surf of 10 to 14 feet is possible for north shores of the Garden Isle, with north shores on Oahu as high as 8 to 12 feet. East shores will be very quiet due to the continued lack of trade winds. Small south and south-southwest swells will keep some wave energy coming to south shores through the weekend.

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