HONOLULU (AP) — Traffic lights malfunctioned and more than half of the Big Island of Hawaii’s electric utility customers lost power as remnants of a former tropical storm battered the island.

Hawaii Electric Light spokeswoman Kristen Okinaka says the utility is investigating the cause of the power interruption but says it’s likely related to the weather.

About 45,000 customers lost power at 10:45 a.m. Monday. All but 1,600 had power restored less than two hours later. The utility has 86,000 customers on the island.

The National Weather Service warned of high surf for east-facing shores of the Big Island through Tuesday morning.

The agency is predicting showers and possibly a thunderstorm as moisture associated with the remnants of Barbara moves over the island.

Barbara was a Category 4 hurricane last week but weakened.