Heavy rain was falling on Kauai this morning as a storm system makes its way down the island chain.

A flash flood watch is in effect for Kauai and Oahu through Friday.

Jonathan Hoag, a forecaster with the Honolulu office of the National Weather Service says Oahu can expect frequent showers, heavy at times with the possibility of thunder showers by tonight.

Hanapepe got an inch of rain in the six-hour period ending at 8 a.m. today, Hoag said.

The storm could also begin bringing rain to Maui and the Big Island sometime tonight.

But before the rain comes, shifting winds from the south may bring vog to Oahu by this afternoon, Hoag said.

Depending on how the winds change as the storm system moves through the islands, the vog could be back tomorrow, Hoag said.

The Big Island and the Kau District which is still suffering from drought, may see some needed rain from this system, Hoag said. 

“We’re hoping they get the rain,” he said. “But the amount of precipitation the Big Island will get is difficult to say.”