Tropical Storm Isaias Floods Part Of Puerto Rico As It Heads Toward Florida

Tropical Storm Isaias is bringing torrential rainfall, high winds and frequent lightning strikes to Puerto Rico on Thursday morning. Isaias is predicted to plow through the Dominican Republic before reaching Florida this weekend.

The storm is "causing life-threatening flash flooding and high winds over Puerto Rico," the National Weather Service office in San Juan said. The storm's impact ranges from fallen trees and power lines to mudslides, according to the office.

Isaias will drop from 4 to 8 inches of rain on Puerto Rico, the Dominican Republic and northern Haiti, the weather service said, with some areas receiving up to 10 inches.

In Miami, the first tropical-storm-force winds could arrive late Friday night, the weather service said.

"Heavy rains associated with Isaias may begin to affect South Florida Saturday morning," the agency said Thursday morning. "This rain could result in isolated flash and urban flooding, especially in low-lying and poorly drained areas."

Isaias is projecting tropical-storm-force winds outward for up to 310 miles – a sign of rapid growth since Wednesday when it became the ninth named storm of the Atlantic season. The National Weather Service categorizes tropical storm winds as ranging from 39 mph to 73 mph (sustained) at surface level.

The storm's maximum sustained winds are at 60 mph, with higher gusts. To be deemed a hurricane, Isaias' sustained winds would need to reach at least 74 mph. Forecasters said the system will weaken as it passes over the Dominican Republic later Thursday, but Isaias will likely restrengthen on Friday and Saturday.

Isaias has triggered tropical storm warnings for a number of islands in the Caribbean, from Puerto Rico and the U.S. Virgin Islands to the Turks and Caicos and parts of the Bahamas.

The system had been steaming on a mostly west-northwest tack — but early Thursday, it took a sharper direction to the northwest. It's now predicted to skirt Florida's Atlantic coast, passing close to West Palm Beach and Port St. Lucie.

The current track doesn't call for Isaias to make a potential landfall on the U.S. mainland until it glances by North Carolina's northern coast — meaning the storm's heavy rains could pose a dangerous flooding threat to low-lying areas along the U.S. Southeastern coast.

Concerns about the storm's impact on Florida prompted officials to suspend coronavirus testing at state facilities for several days, from Friday through at least Tuesday.

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