Weather forecasters believe the disturbance, dubbed Invest 95L, could become a depression or a storm later today or on Friday.
The chances that a tropical cyclone will form near South Florida this weekend are escalating as an area of widespread storminess over the southeastern Bahamas gets better organized.
National Hurricane Center forecasters began issuing advisories Thursday on Potential Tropical Cyclone Nine - a designation that allows watches and warnings to go into effect before a disturbance is fully developed.
Tropical storm warnings were issued by the government of the Bahamas for its northwesthern islands including Grand Bahama and the Abacos, which were just devastated by Category 5 Hurricane Dorian.
Florida's east coast could see watches and warnings issued overnight or Friday as the forecast track of the system brings it to Florida’s east coast on Saturday.
If a tropical storm forms, it would be named Humberto.
The official forecast has the system topping out as a tropical storm with 50 mph winds with a possible path that includes areas from Hollywood through Jacksonville and west to Tallahassee.
Robert Molleda, warning coordination meteorologist with the National Weather Service in Miami, said South Florida’s weekend weather depends on where the system tracks.
If a tropical depression or storm develops north of the Bahamas off Florida’s central coast, it could mean lower chances of rain over the weekend.
A path that develops the system farther south would mean gusty to tropical-storm-force winds and rainfall amounts as high as 5 inches in coastal Palm Beach County.
“The worse case scenario would be a tropical storm affecting South Florida and moving right over it, and that’s certainly a possibility,” Molleda said. “Right now we should prepare for the potential for a windy, rainy event with showers increasing Friday.”
The squally weather is expected to be the strongest Friday night through Saturday with rain chances as high as 70 percent both days.
Unlike Hurricane Dorian’s damaging stall over the Bahamas, 95L was moving west-northwest at 10 to 15 mph and should continue to be steered by a high pressure system to its north.
The National Weather Service in Miami is warning of possible tornadoes as the system passes near South Florida. A high risk of dangerous rip currents is in place at least through Friday. Heavy rain with localized flooding are also possible.
The region NHC has marked for development of the disturbance stretches from the southeastern Bahamas into Florida’s Big Bend region.
Sea surface temperatures in the Gulf of Mexico are running between 84 and 88 degrees, which is plenty warm to feed a growing storm if it takes that route.
The system is also expected to find less wind shear in the eastern Gulf, which could buoy development.
Weather Underground co-founder Jeff Masters said there the system’s path is “highly uncertain.”
Leading weather models have two different tracks, one taking it across South Florida into the Gulf of Mexico and another running it up the east coast on a path similar to Dorian’s.
“It will be highly dependent upon where and when the center ultimately forms, and that location could be anywhere within a 100-mile radius of the south-central Bahamas,” Masters wrote in a forecast Thursday. “The main thing we are sure about at this point is that 95L will bring regions of heavy rains of 2 to 4 inches over the next two days to The Bahamas, including the islands devastated by Hurricane Dorian.”
The NHC is also watching a second system in the tropical Atlantic that was picking up steam Thursday.
The wave, located just west of the Cabo Verde Islands, is producing a small area of disorganized showers and thunderstorms. With conditions improving ahead of it for development, the NHC is giving the system a 40 percent chance of formation over five days.
After Humberto, next name on the 2019 tropical cyclone list is Imelda.
Storm advisories may commence later today or tomorrow as a vigorous tropical disturbance bears down on the Bahamas and the Florida peninsula, forecasters say.
In its 1 p.m. CDT statement the National Hurricane Center said the disturbance shows signs of becoming a storm, based on satellite and surface reports. Barometric pressures are low in the area and conditions are conducive for strengthening, the statement indicated.
The disturbance was moving toward the northwest at 5 to 10 mph and appeared to be headed toward the Bahamas and the Florida peninsula.
Forecasters advised people in the central and northwestern Bahamas as well as Florida to keep an eye on the system.
It was expected to bring heavy rainfall and gusty winds to the Bahamas through Friday, including areas affected by Hurricane Dorian.
An Air Force plane is scheduled to investigate the disturbance today.
The chances of development are 70 percent through 48 hours and 80 percent through five days.