Tropical Storm Maria's projected path remains uncertain.

Tropical Storm Maria's projected path remains uncertain. (National Hurricane Center)

Tropical Storm Maria was barely surviving on Thursday afternoon, with slow strengthening expected Friday night and Saturday.

And it still holds potential to regenerate to close to hurricane strength over the next five days, the National Hurricane Center said.

At 5 a.m. on Friday, Maria was in the Atlantic about 435 miles southeast of the Leeward Islands, heading northwest at 18 mph with sustained winds of 40 mph. Its top winds had been 50 mph earlier.

Under the latest forecast, Maria is projected to approach the Leeward Islands on Friday as it approaches the Lesser Antilles. It then is expected to regain tropical storm status on Sunday northeast of theDominican Republic.

The system is predicted to draw just east of the Bahamas on Tuesday with top winds of 70 mph, or just 4 mph shy of hurricane strength. At that point, it would be about 350 miles due east of Miami.

If that forecast holds, South Florida likely would escape feeling the storm's worst weather, but the rest of the state as well as the U.S. coast would remain at risk, as the projected path has been shifted west.

Ever since it emerged on Wednesday, Maria has been battling wind shear. However, the shear should ease as the system moves north of Puerto Rico and Hispaniola, senior hurricane specialist Lixion Avila of the National Hurricane Center said.

The hurricane center also is monitoring two other systems.

Tropical Storm Nate, which was on the verge of becoming a hurricane, weakened slightly overnigt.  Nate is predicted to curve northwest in the southern Gulf of Mexico toward Mexico or Texas.

At 5 a.m. on Friday, it was about 115 miles west of Campeche, Mexico, stationary with sustained winds of 65 mph.

Hurricane Katia continued its trek into the North Atlantic, where it is expected to fizzle within the next three or four days.

At 5 a.m. on Friday, the storm was about 525 miles southwest of Halifax, Nova Scotia moving northest at 24 mph with sustained winds of 85 mph.