Very dangerous Hurricane Irma reached category 5 on the Saffir-Simpson Scale on Tuesday morning. At 11:00 a.m. EDT on Tuesday the center of Hurricane Irma was located at latitude 12.3°N and longitude 39.1°W which put it about 225 miles (365 km) east of Antigua. Irma was moving toward the west at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 180 m.p.h. (285 km/h) and there were wind gusts to 210 m.p.h. (340 km/h). The minimum surface pressure was 931 mb.
Hurricane Warnings are in effect for Antigua, Barbuda, Anguilla, Montserrat, St. Kitts, Nevis, Saba, St. Eustatius, Sint Maarten, St. Martin, St. Barthelemy, the British Virgin Islands, the U.S. Virgin Islands, Puerto Rico, Vieques and Culebra. Tropical Storm Warnings are in effect for Guadeloupe and Dominica. Hurricane Watches are in effect for Guadeloupe, the southeastern Bahamas including the Acklins, Crooked Islands, Long Cay, the Inaguas, Mayaguana, and the Ragged Islands. A Hurricane Watch is also in effect for the portion of the the coast from Cabo Engano, Dominican Republic to Le Mole St. Nicholas, Haiti. Tropical Storm Watches are in effect for the portion of the coast from Le Mole St. Nicholas to Port Au Prince, Haiti and from Cabo Engano to Isla Saona, Dominican Republic.
Hurricane Irma intensified rapidly after the completion of the most recent eyewall replacement cycle. The structure evolved in a large classic Cape Verde hurricane. The is a large circular eye at the center of circulation. A ring of very strong thunderstorms surrounds the eye and the strongest winds are occurring in that ring. Bands of showers and thunderstorms are revolving around the core of Hurricane Irma. Winds to hurricane force extend out about 60 miles (95 km) from the center of circulation. Winds to tropical storm force extend out about 160 miles (260 km) from the center.
The Hurricane Intensity Index (HII) for Irma is 44.1. The Hurricane Size Index (HSI) is 19.8 and the Hurricane Wind Intensity Size Index (HWISI) is 63.9. Hurricane Irma is as strong as Hurricane Rita was in 2005, but Irma is just slightly smaller than Rita was. Hurricane Irma is capable of causing widespread catastrophic damage.
Hurricane Irma is moving through an environment that is very favorable for hurricanes. Irma is moving over water where the Sea Surface Temperature is near 30°C. The upper level winds are weak and there is little vertical wind shear. Hurricane Irma will likely remain very strong as long as it stays over water. Additional eyewall replacement cycles could occur and they would result in fluctuations in the intensity of Hurricane Irma.
Hurricane Irma is being steered to the west by a very strong subtropical high over the Atlantic Ocean. Irma is expected to turn a little more toward the west-northwest as it moves closer to the western end of the high. On its anticipated track Hurricane Irma will move across the northern Leeward Islands during the next 24 hours. It will be near Puerto Rico on Wednesday and near the Dominican Republic on Thursday.
Hurricane Irma is an very dangerous hurricane. It is capable of producing widespread catastrophic damage. Hurricane Irma will also drop extremely heavy rain and flooding is very possible.