Irma maintains Category 4 wind speeds as it moves toward Florida

Forecasters say Irma will remain a Category 4 hurricane until the center of the storm makes landfall later on Sunday.

Irma had sustained winds at 115 knots as of 11 a.m., the National Weather Service reports.

Once Irma makes landfall, the storm is expected to decrease in intensity after it makes contact with the southwest Florida coast, and then weaken as it moves north over the western Florida coast and into the panhandle.

More rapid weakened is expected as Irma moves over the southern United States on Monday.

The track continues to shift to the west, with the storm center forecast to be over northern Alabama early Tuesday.

As of 11 a.m., forecasters with Columbia’s National Weather Service office have downgraded the expected effects of Irma. Rainfall of 2 to 3 inches is forecast Monday from Columbia and Sumter northward, with 3 to 5 inches elsewhere, with some areas seeing as much as seven inches.

The track doesn’t mean South Carolina will be unaffected, however. Forecasters expect the storm to bring wind hazards and up to 20 inches of rain in southern and western South Carolina. Wind speeds could reach up to 60 miles per hour in parts of the South Carolina Midlands.

On Saturday, Gov. Henry McMaster reported that eight coastal islands had evacuated smoothly after an evacuation order was issued, and transportation officials say traffic congestion on S.C. interstates had dropped, to 15 percent the normal load.

Storm surges are expected along much of the South Carolina coast as Irma approaches. A lake wind advisory remains in effect throughout the state, and a high-wind watch for Midlands counties for tropical storm force winds is in effect through Monday evening.

Wind gusts of 50 miles per hour or higher could cause damage to trees, signs and outbuildings, Columbia’s National Weater Service office warns. Damage to mobile homes and power outages should be expected.

That will create the threat of flash flooding, with river flooding in some areas throughout the week. Tornadoes are also possible Monday.

This story was originally published September 10, 2017 at 11:43 AM with the headline "Irma maintains Category 4 wind speeds as it moves toward Florida."