Track keeps Hurricane Irma heading to South Florida

Hurricane Irma remained a ferocious Category 5 hurricane Thursday as it sideswiped Puerto Rico and Hispaniola overnight, with a hurricane watch expected for South Florida and the Keys later this morning.

Over the next 48 hours, Irma should continue heading west-northwest on a track increasingly likely to steam across the state’s crowded east coast and arriving in three to four days, National Hurricane Center forecasters said early Thursday. A high pressure ridge is steering the storm, but the ridge is expected to collide with a low pressure trough moving across the U.S and weaken, letting Irma turn north.

Exactly when and where that happens remains uncertain. But Thursday’s early computer runs continue to turn Irma sooner, rather than later. Tropical storm force winds are expected to reach the Keys and South Florida by early Saturday.

Overnight, sustained winds dropped slightly to 180 mph, with Irma’s eye clouding over. The storm became a little less organized, forecasters said, but only slightly so. And while fluctuations in intensity are expected, it will almost certainly remain a fierce Cat 4 or 5 storm in the coming days, they said.

At 8 a.m., Irma was located about 110 miles north of the Dominican Republic’s east coast, heading west-northwest at 18 mph. Hurricane winds extend 50 miles from the storm’s center, with tropical storm force winds reaching nearly 200 miles.

In the coming hours, Irma is expected to swipe the north coast of Hispaniola with powerful winds, damaging storm surge and heavy rain before heading to the southeastern Bahamas and Turks and Caicos later in the day, forecasters said. It should near the Central Bahamas Friday.

The low-lying Bahamas and Turks and Caicos may get hammered with high storm surge, reaching as much as 20 feet above normal tide levels Thursday night and possibly early Friday, forecasters said. Rainfall could reach eight to 12 inches. On the island of South Caicos, officials cut off power early this morning in advance of the storm.

Irma has killed at least 10 people and injured 23 across the western Caribbean.

French Interior Minister Gerard Collomb told the Associated Press the death toll in Saint-Martin and Saint-Barthelemy could be higher because rescue teams have not finished inspecting the islands.

"The reconnaissance will really start at daybreak," Collomb said.

Barbuda suffered damage to 95 percent of the island, Prime Minister Gaston Browne said.

"I felt like crying," he said after seeing the devastation, "but crying will not help."

Puerto Rico narrowly dodged Irma’s strongest winds but still suffered widespread blackouts, with about 70 percent of the island without power Thursday morning. Three deaths were blamed on the storm.

Over the next two days, the latest model runs show Irma moving in the same direction around the southwestern edge of the ridge and and beginning to slow. The trough — moving from the Midwest and tracked by meteorologists around the country with weather balloons launched every six hours — should begin to erode the ridge Saturday, letting Irma slide north.

But the timing and speed of the turn is less certain, forecasters said, leaving Irma’s swath of destruction up in the air and a margin of error of about 120 miles at three days and 175 miles at four days.

Three models show a later turn, once the storm enters the Gulf of Mexico, near Florida’s west coast, while the reliable European model has Irma turning sooner and heading over southeast Florida. The U.S. model turns Irma even sooner and cruising up the east coast.

Based on trends, and a widely regarded Florida State University model, forecasters believe Irma will likely head over southeast Florida in the next 72 to 96 hours.

Forecasters are also tracking a second hurricane, Jose, in the eastern Atlantic. Early this morning, the hurricane was located about 800 miles east of the Lesser Antilles with sustained winds of 90 mph. The compact storm, with hurricane winds extending just 15 miles from its center, is expected to near the islands Saturday.

Staff writer Jacqueline Charles and the Associated Press contributed to this story.

This story was originally published September 7, 2017 at 7:51 AM with the headline "Track keeps Hurricane Irma heading to South Florida."