(BIVN) – The National Weather Service in Honolulu has issued a Flood Watch for all the main Hawaiian islands – while heavy snow and strong winds are expected at the summits, and high surf along south-facing shores – over the next several days.

Flash flooding caused by excessive rainfall will be possible through late Friday, forecasters report, following up on a Special Weather Statement that was issued on Wednesday.

At the Big Island summits, a Winter Storm Warning and a High Wind Warning will be in effect from noon Friday to 6 a.m. on Saturday. “Heavy snow and very strong winds expected,” the National Weather Service stated. Total snow accumulations of up to 6 inches, with winds gusting over 70 mph, are expected.

“Travel could be very difficult to impossible,” forecasters warned travelers to Maunakea and Mauna Loa. “Blowing snow will significantly reduce visibility at times, with periods of zero visibility.”

Also, large breaking waves of 7 to 10 feet are expected along south-facing shores through Friday evening.

From the National Weather Service:

A strong upper level disturbance will bring heavy showers and isolated thunderstorms tonight through Friday and Friday night. The heaviest downpours will be hit or miss, but where they do occur, they will be capable of producing rainfall rates in excess of 3 inches per hour. The threat for flash flooding is expected to be the greatest Friday through Friday evening. Conditions should steadily improve from west to east late Friday into Saturday.

The Hawaiʻi County Civil Defense issued a radio message concerning the Flood Watch on Thursday. Emergency officials stated:

• Thunderstorms will produce heavy rains, high winds and lightning.
• Residents in flood prone areas should be prepared for heavy rains and potential flooding
• Be aware that road closures may occur without notice
• Do not attempt to cross flowing water in a vehicle or on foot; turn around don’t drown.
• If lightning threatens your area, the safest place to be is indoors.