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.

SEVERITY Category 5 4 3 2 1 Tropical storm Source: National Weather Service

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.

Much of Florida Lost Power

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

Tallahassee Jacksonville Percentage of people without power per county 80 or more 60 40 20% Orlando Tampa Fort Myers Naples Miami Key West Tallahassee Jacksonville Percentage of people without power per county Orlando 80 or more 60 40 20 Tampa Fort Myers Miami Key West Tallahassee Jacksonville Orlando Percentage of people without power per county Tampa 60 20% 40 80 or more Fort Myers Miami Key West Source: Florida Division of Emergency Management

Damage Across Florida

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

Miami Miami Beach Cape Coral Fort Myers Fort Lauderdale Palm Bay Daytona Beach Near the Miami River Naples Miami Dania Beach Bonita Springs

Predicted Storm Surge Along the Coast

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.

Surge of more than 1 ft. above ground 3 ft. 6 ft. 9 ft. Areas often flooded at high tide GEORGIA Tallahassee Jacksonville Orlando Atlantic Ocean Tampa St. Petersburg FLORIDA Gulf of Mexico Lake Okeechobee West Palm Beach Fort Myers Fort Lauderdale Naples Miami GEORGIA Jacksonville Orlando Atlantic Ocean Tampa St. Petersburg FLORIDA Gulf of Mexico Lake Okeechobee West Palm Beach Fort Myers Fort Lauderdale Naples Miami GEORGIA Jacksonville Atlantic Ocean Orlando Tampa St. Petersburg FLORIDA West Palm Beach Gulf of Mexico Lake Okeechobee Fort Myers Fort Lauderdale Naples Miami Source: National Weather Service. | Note: Map shows potential storm surge flooding from 11 a.m. Eastern on Sept. 10 to 5 p.m. on Sept. 13.

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.

Where Irma Is Headed

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.

Source: European Center for Medium-Range Weather Forecasts, National Weather Service

Storm Tracking: Irma, Jose and Katia

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.

SEVERITY Category 5 4 3 2 1 Tropical storm Source: National Weather Service

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.

States Order Mandatory Evacuations

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.

Counties under evacuation Mandatory Partial mandatory Partial voluntary ALABAMA Savannah GEORGIA Jacksonville FLORIDA Orlando Tampa Gulf of Mexico Fort Myers Naples Miami ALABAMA Savannah GEORGIA Jacksonville FLORIDA Orlando Tampa Fort Myers Gulf of Mexico Miami Naples Map shows evacuation orders as of 10 a.m. Eastern on Sept. 8.

The Strongest Storm So Far East in the Atlantic

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.

Strongest Atlantic Hurricanes MISS. GA. ALA. Stronger winds Wilma, 2005 185 m.p.h. LA. TEX. FLA. Gulf of Mexico Rita, 2005 180 m.p.h. Allen, 1980 190 m.p.h. Labor Day, 1935 185 m.p.h. Atlantic Ocean CUBA Irma, 2017 185 m.p.h. Gilbert, 1988 185 m.p.h. haiti dominican republic MEXICO PUERTO RICO JAMAICA BELIZE GUATEMALA Caribbean Sea HONDURAS Mitch, 1998 180 m.p.h. EL SALVADOR Pacific Ocean NICARAGUA GA. Stronger winds ALA. Wilma, 2005 185 m.p.h. LA. MISS. TEX. Rita, 2005 180 m.p.h. FLA. Labor Day, 1935 185 m.p.h. Gulf of Mexico Atlantic Ocean Irma, 2017 185 m.p.h. CUBA Gilbert, 1988 185 m.p.h. dominican rep. haiti PUERTO RICO MEXICO Caribbean Sea Mitch, 1998 180 m.p.h. Allen, 1980 190 m.p.h. Pacific Ocean VENEZUELA COLOMBIA GA. Stronger winds ALA. Wilma, 2005 185 m.p.h. LA. MISS. TEX. Rita, 2005 180 m.p.h. FLA. Labor Day, 1935 185 m.p.h. Gulf of Mexico Atlantic Ocean Irma, 2017 185 m.p.h. CUBA Gilbert, 1988 185 m.p.h. dominican rep. haiti PUERTO RICO MEXICO Caribbean Sea Mitch, 1998 180 m.p.h. Allen, 1980 190 m.p.h. Pacific Ocean VENEZUELA COLOMBIA GA. Stronger winds ALA. LA. Wilma, 2005 185 m.p.h. MISS. TEX. FLA. Rita, 2005 180 m.p.h. Labor Day, 1935 185 m.p.h. Gulf of Mexico Atlantic Ocean Irma, 2017 185 m.p.h. CUBA Gilbert, 1988 185 m.p.h. P.R. MEXICO Caribbean Sea Mitch, 1998 180 m.p.h. Allen, 1980 190 m.p.h. Pacific Ocean VENEZUELA MS GA LA AL TX Atlantic Ocean FL Gulf of Mexico Hurricane Irma 185 m.p.h. CUBA MEXICO P.R. Caribbean Sea NICARAGUA Stronger winds VENEZUELA COLOMBIA Sources: Hurricane Research Division, National Oceanic and Atmospheric Administration

Hurricane Irma Enters the Caribbean

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.

Source: NASA

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.