Tropical Storm Hilda was moving slowly westward and weakening but still could bring heavy rain to the state, starting with Hawaii island Thursday.

"While this system will pass sufficiently south of the Hawaiian islands to avoid direct impacts, the associated moisture plume may provide flooding rainfall for portions of the Aloha State," forecasters with the Central Pacific Hurricane Center said late Wednesday.

Hilda was downgraded from a hurricane to a tropical storm Tuesday and officials project it to become a tropical depression, with sustained maximum winds below 39 mph, Thursday and a remnant low by Friday "or sooner," according to the hurricane center.

As of 5 a.m. Thursday, the storm had maximum sustained winds of 40 mph, down from 45 mph Wednesday night. A category 1 hurricane features minimum sustained winds of 74 mph.

National Weather Service forecasters said steady weakening is expected over the next couple of days. The forecast track for Hilda has shifted south of the islands.

A tropical storm watch for Hawaii island was canceled Wednesday evening. But a flash flood watch is in effect through 6 a.m. Saturday, with forecasters expecting rain amounts of 4 to 8 inches, and up to 12 inches possible in some areas, especially east-and southeast-facing slopes.

A high surf advisory is in effect for east-facing shores of Maui and the Big Island until 6 p.m. Thursday, with waves from 8 to 12 feet possible.

Westerly winds were slowing the progress of the storm, which was about 210 miles south-southeast of Hilo and 410 miles southeast of Honolulu at 5 a.m. Thursday. The storm was moving west at about 9 mph with tropical storm force winds extending outward up to 60 miles.

Hilda’s strength peaked as a category 4 hurricane on Saturday with 140 mph winds.

Even though the storm is weakening and is moving south of the islands, forecasters still say it is capable of producing heavy rainfall that could result in dangerous flash floods and mud slides across portions of the islands into Saturday.