2017 Hurricane Irma Tracker Guide

Hurricane Irma is a powerful tropical cyclone that is currently affecting Cuba and the U.S. state of Florida as a major hurricane. It is the strongest hurricane ever recorded in the Atlantic basin outside the Caribbean and Gulf of Mexico, and is tied with the 1935 Labor Day hurricane as the strongest landfalling cyclone on record in the Atlantic basin as well as the strongest Atlantic hurricane since Wilma of 2005 in terms of maximum sustained winds, the most intense in terms of pressure since Dean in 2007, and the first of such intensity to make landfall anywhere in the Atlantic since Felix in 2007. Irma is also the first Category 5 hurricane on record to affect the northern Leeward Islands, and only the second hurricane on record to make landfall in Cuba at such an intensity, with the other being a hurricane in 1924.

A typical Cape Verde hurricane,[1][2][3] Irma developed on August 30 near the Cape Verde Islands from a tropical wave that had moved off the west African coast two days prior. It is the ninth named storm, fourth hurricane, and second major hurricane of the 2017 Atlantic hurricane season.[4][5][6] Under favorable conditions, Irma rapidly intensified shortly after formation, becoming a Category 2 hurricane on the Saffir–Simpson scale within a mere 24 hours. It became a Category 3 hurricane (and therefore a major hurricane) shortly afterward; however, the intensity fluctuated for the next several days due to a series of eyewall replacement cycles. On September 5, Irma became a Category 5 hurricane, and by early the next day, Irma reached peak intensity with 185 mph (295 km/h) winds and a minimum pressure of 914 mbar (914 hPa; 27.0 inHg). This ties it as the second-strongest Atlantic hurricane by wind speed, surpassed only by Allen of 1980 which reached wind speeds of 190 mph (305 km/h). Irma sustained these 185 mph (295 km/h) winds for 37 hours, surpassing Allen's record, which had sustained 180 mph (285 km/h) winds for 18 hours.[7] In addition, Irma achieved one of the longest durations of Category 5 strength winds ever on record. Irma's low pressure also makes it the strongest tropical cyclone worldwide in 2017 so far. After dropping to Category 3 as it passed along Cuba, on September 10 the storm rose to Category 4 once more as it crossed warm waters between Cuba and the Florida Keys.

It caused catastrophic damage in Barbuda, Saint Barthélemy, Saint Martin, Anguilla and the Virgin Islands as a Category 5 hurricane. Irma was the strongest hurricane to strike the northern Leeward Islands and one of the worst storms to hit the region, along with Hurricane Donna in 1960 and Hurricane Luis in 1995. As of September 9, the hurricane has caused at least 27 deaths (three in Anguilla, three in Barbados, one in Barbuda, twelve in the French West Indies, three in Puerto Rico, two on the Dutch side of Saint Martin, one in the contiguous United States, and four in the U.S. Virgin Islands).