The public should be prepared for potentially damaging high surf on Oahu’s north and west shores that could cause coastal flooding, damage to homes, and road closures today, the city Department of Emergency Management said.

The National Weather Service has issued a high-surf warning from noon today for north- and west-facing shores of Oahu and parts of Kauai, Molokai and Maui. The warning was set to expire at noon Friday.

Surf will increase rapidly today, reaching 30 to 40 feet along north- and west-facing shores on Kauai, 25 to 35 feet along the north shore of Oahu, and 20 to 30 feet along the west shore of Oahu and north shores of Molokai and Maui.

A low-pressure system with hurricane-force winds northwest of Kauai generated this swell, which is expected to reach Kauai first, then work its way down the island chain.

The swell has a westerly component that will produce larger-than-normal surf along west-facing shores and possible wave run-up along Leeward Oahu, the weather service said.

"Although previous warnings did not produce many problems for Oahu residents, this high-surf event has the potential to generate coastal flooding, cause damage to homes located on or near affected beaches, create road closures and other hazards," the city Department of Emergency Management said.

Residents are urged to take measures to protect their property and prepare to evacuate if necessary, the department said. Motorists driving along affected shores should exercise caution as roads can become blocked with sand and debris.

Meanwhile, a cold front over parts of the state is expected to drop as much as 6 inches of snow on the summits of Mauna Loa and Mauna Kea overnight, the weather service said.

A winter storm watch is in effect until this afternoon for the summits because of the potential for significant snow, sleet or ice affecting travel.

The same storm was forecast to bring heavy showers, thunderstorms and flash flooding to Maui and the Big Island last night.

The flash flood watch lasts until this afternoon, the weather service said.