Maps: Tracking Hurricane Irma’s Path Over Florida

Hurricane Irma lost strength as it swept across Florida, and was downgraded to a tropical storm on Monday morning. All times on the maps are Eastern.

Tropical-storm-force winds range from 39 to 73 miles per hour, and hurricane-force winds are all those above 73 m.p.h. The zones for wind speed, which are reported only every three to six hours, may lag the hurricane track on the map.

Six million customers in Florida, or about two-thirds of the state, had power outages as of 9 a.m. on Monday.

Initial reports of Irma’s impact included damaged structures and some flooding in parts of Miami and other cities.

A storm surge of up to 15 feet had been predicted along the west coast of Florida, but the city of Naples saw less flooding than expected on Sunday. In Miami, the surge was about three feet above normal sea level.

A flood gauge in Naples Bay showed about a three-foot drop in sea level earlier on Sunday, leaving boats high and dry in their slips. But in the afternoon, the sea level rose about about eight feet in three hours.

One of the best hurricane forecasting systems is a model developed by an independent intergovernmental organization in Europe, according to Jeff Masters, a founder of the Weather Underground. The system produces 52 distinct forecasts of the storm’s path, each represented by a line below.

Hurricane Irma was one of three major Atlantic storms that has threatened the region this past week. Katia made landfall late Friday night on the eastern coast of Mexico and lost much of its energy; it is no longer a hurricane.

As of Monday morning, Hurricane Jose, downgraded to a Category 2 storm, had moved farther north of the Leeward Islands than initially predicted, and it seemed to have spared Puerto Rico and the rest of the Caribbean islands.

Mandatory evacuations have been ordered in 16 Florida counties and voluntary evacuations have been ordered in 13 additional counties. In Georgia, Gov. Nathan Deal ordered a mandatory evacuation for the city of Savannah and other coastal areas. On Friday, Gov. Henry McMaster of South Carolina ordered the evacuation of several barrier islands, beginning at 10 a.m. on Saturday.

With winds of up to 185 m.p.h., Hurricane Irma is tied with three other hurricanes as the Atlantic’s second-strongest storm. “We’ve had storms this strong before, but most form further west, in the Western Caribbean and the Gulf,” said Philip Klotzbach, a meteorologist at Colorado State University who specializes in Atlantic basin seasonal hurricane forecasts. “The impressive thing with Irma is that it is this strong over the tropical Atlantic.”

The map below shows Irma’s position on Sept. 7.

Satellite imagery shows the storm, one of the strongest ever recorded in the Atlantic Ocean, when it was barreling toward Puerto Rico, which it sideswiped before churning north.

The eye of the storm was bigger than some Caribbean islands, and it moved directly over the island of Barbuda early Wednesday morning. In this high-resolution NASA image, Barbuda is a few pixels of green.