Winds will shift out of the south over the next 24 hours, bringing showers over the Hawaiian isles, forecasters said, as a cold front approaches from the west.

The National Weather Service now expects the fast-moving cold front to reach Kauai on Wednesday, sweep across Oahu and Maui County Wednesday night, then travel across Hawaii island Thursday, bringing widespread rain, gusty winds, and a few thunderstorms.

Snow is expected to once again blanket Big Isle summits at Mauna Kea and Mauna Loa as temperatures drop.

Today’s forecast is partly sunny for most isles, with scattered showers and highs from 78 to 83 degrees Fahrenheit. Skies will be mostly cloudy tonight, with lows dipping to 66 to 71 degrees. Southeast winds of 15 mph shift to south winds of 15 to 20 mph tonight.

Hawaii island can expect afternoon haze, with increasing clouds and showers in the Puna and Kau regions tonight.

Surf is building for northwest shores due to a series of small, northerly swells — from 3 to 5 feet for north shores today to 8 to 12 feet Wednesday morning, and 12 to 16 feet Wednesday evening, and from 1 to 3 feet for west shores today to 7 to 10 feet on Wednesday

Elsewhere, surf remains stable at 1 to 3 feet for south shores, and 2 to 4 feet for east shores, today and Wednesday.

Forecasters are expected a much larger, northwest swell during the latter half of this week, potentially bringing advisory level surf to the west shores of Hawaii island.

Cooler, dry air and strong, northeast winds are expected behind the front, dropping temperatures below normal for the rest of the week and into the weekend.