Hurricane Felicia waning on its way to Hawaii

(CNN) -- Hurricane Felicia weakened Friday as it headed toward Hawaii and may continue to wane, but forecasters have not discounted the threat of flooding on the island chain.

The storm was downgraded to a Category 2 hurricane as it moved west-northwest toward Hilo, Hawaii, at 13 mph (20 kmh). Felicia's maximum sustained winds slowed from 140 mph (220 kmh) Thursday to near 100 mph (185 kmh) as of 8 a.m. PT Friday, according to the National Hurricane Center in Miami, Florida.

Felicia is expected to weaken further as it moves over cooler waters, according to the hurricane center.

Felicia could reach Hawaii by Monday, but by that time it may have weakened to a tropical depression or tropical storm, said meteorologist Derek Wroe at the Central Pacific Hurricane Center in Honolulu, Hawaii.

Even if the storm does not hit Hawaii as a hurricane, it can still cause flooding damage, Wroe said.

"[Storms and depressions] bring a lot of moisture with them and the wind may not be as strong when it comes in with a depression, but a depression is sometimes just as capable as bringing in flooding as a tropical storm," Wroe said.

Felicia is about 1,280 miles east (2,060 kilometers) of the Big Island, according to the weather service.

Wroe expects the hurricane to continue westward after it strikes Hawaii, bringing rain to one or more of the islands for a day or part of a day as it moves along, he said. If the hurricane sweeps through each island, it could take a couple of days before Hawaii is in the clear, he said.