Tropical Storm Irene has slowed in forward moving as she passes near Puerto Rico Sunday evening, but still has South Florida in her long-range forecast track.
"We're still not in the clear. People should watch how things unfold," said Dr. Christina Forbes of the National Hurricane Center on Sunday afternoon. "The models show a large spread, so some are ticking to the west coast and some are ticking east to the Bahamas. We still need to watch some more for how it evolves over time."
At 8 p.m. Sunday, Irene had increased maximum sustained winds of 60 miles per hour, according to data from an Air Force hurricane hunter plane.
The system is now moving west-northwest in the Caribbean at 15 miles per hour, down from 20 earlier Sunday, but is expected to strengthen further.
The ninth named storm of the season could reach hurricane status Monday near the Dominican Republic, according to the current NHC forecast.
"At this time, everyone [in South Florida] should be in a watch and wait mode," said NHC forecaster Todd Kimberlain. "In terms of where it will be in five days, there's still a lot of uncertainty."
"Now would probably be a good time to make sure you have supplies and a hurricane plan."
Irene was about 10 miles northwest of St. Croix and 90 miles east-southeast of San Juan at 8 p.m. Sunday as tropical storm conditions spread over eastern Puerto Rico.
Hurricane warnings have been issued in the Dominican Republic and Puerto Rico, and a hurricane watch is in effect for the U.S. Virgin Islands.
Tropical storm warnings and watches have been issued for the Bahamas, Turks and Caicos, St. Martin, St. Barthelemy, British Virgin Islands, and Haiti.