Hurricane Irma as the storm approached Cuba (Source: NASA)

Hurricane Irma could cause up to 15 feet of storm surge and historic flooding in Collier and Lee counties , according to the National Weather Service.

Storm surge flooding in the coastal Southwest Florida counties is expected to start Monday as Irma moves north and the hurricane’s counterclockwise rotation pushes winds inland from the Gulf of Mexico.

Dana Summers, director of the Bureau of Emergency Services in Collier County, said people in areas of the county most vulnerable to flooding have been ordered to evacuate.

Irma weakened to a Category 3 hurricane on Saturday but is expected to strengthen as it approaches southern Florida.

In an advisory at 5 p.m. Saturday, the National Hurricane Center reported that Irma had started to move away from Cuba with maximum sustained winds of 125 miles per hour. [Naples Daily News]Mike Seemuth