Category 5 Hurricane Maria Bearing Down on Puerto Rico

Category 5 Hurricane Maria was bearing down on Puerto Rico on Tuesday night.  The eye was very near St. Croix.  At 11:00 p.m. EDT on Tuesday the center of Hurricane Maria was located at latitude 17.3°N and longitude 64.7°W which put it about 30 miles (45 km) south-southeast of St. Croix and about 120 miles (190 km) southeast of San Juan, Puerto Rico.  Maria was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 175 m.p.h. (280 km/h) and there were wind gusts to 215 m.p.h. (345 m/h).  The minimum surface pressure was 909 mb.

Hurricane Warnings were in effect for Puerto Rico, Culebra, Vieques, the U.S. Virgin Islands, the British Virgin Islands, and for the portion of the coast from Cabo Engano to Puerto Plata, Dominican Republic.  Hurricane Watches were in effect for the Turks and Caicos, the Southeastern Bahamas, Saba, St. Maarten, St. Martin, St. Eustatius, St. Barthelemy, and the portion of the coast from Isla Saona to Cabo Engano, Dominican Republic.  Tropical Storm Warnings were in effect for Saba, St. Eustatius, St. Maarten, the portion of the coast from Puerto Plata,, Dominican Republic to the northern border with Haiti and for the portion of the coast from Cabo Engano to Punta Palenque, Dominican Republic,

Hurricane Maria is a very well organized powerful hurricane.  It has a small inner eye and a second outer eyewall extends most of the way around the inner eyewall.  The strongest winds are occurring in the inner eyewall.  Additional spiral bands are revolving around the core of the circulation.  The concentric eyewalls have caused the circulation of Hurricane Maria to increase in size.  Winds to hurricane force now 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 Hurricane Maria is 40.4.  The Hurricane Size Index (HSI) is 19.2 and the Hurricane Wind Intensity Size Index (HWISI) is 59.6.  Those indices indicate that Hurricane Maria is capable of causing regional catastrophic damage.

Hurricane Maria will continue to move through an environment favorable for powerful hurricanes until it reaches Puerto Rico.  Maria will move over water where the Sea Surface Temperature is near 29°C.  The upper level winds are weak and there is little vertical wind shear.  If the outer eyewall completely encircles the inner eyewall, then an eyewall replacement cycle could cause some weakening.  Hurricane Maria will weaken more if the center moves directly over Puerto Rico.  The amount of weakening will depend on the stage of the eyewall replacement cycle at the time of landfall.

Hurricane Maria is being steered toward the west-northwest by the subtropical high pressure system over the Atlantic Ocean.  The western end of the high is forecast to weaken during the next several days.  The weakening of the high will allow Hurricane Maria to move more toward the north.  The core of Hurricane Maria will pass near or over St. Croix during the next few hours.  On its anticipated track Hurricane Maria will reach Puerto Rico on Wednesday morning.

Hurricane Maria is a very dangerous hurricane.  It is capable of causing catastrophic damage.  Maria will also drop very heavy rain over Puerto Rico and there is the potential for significant flash flooding.  Maria could also cause a storm surge of up to 12 feet (4 meters) along the coast.

Elsewhere, Hurricane Jose weakened to a tropical storm east of the U.S.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Jose was located at latitude 37.9°N and longitude 70.8°W which put it about 230 miles (375 km) south of Nantucket.  Jose was moving toward the northeast at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 973 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Woods Hole to Sagamore Beach, Massachusetts including Block Island, Martha’s Vineyard, Nantucket and Cape Cod.  A Tropical Storm Watch was in effect for the portion of Long Island from Fire Island Inlet to Port Jefferson.