Subtropical storm Alberto, appearing a week before the official start of hurricane season, maintained sustained winds of 40 mph and halted its forward movement Friday afternoon, although it is expected to resume a course toward the coasts of Louisiana, Mississippi and Alabama.
The storm’s sustained winds are expected to intensify to 65 mph over the next three days, as it approaches the northern Gulf coast. This would make Alberto a strong subtropical storm, although well short of the 74 mph threshold for hurricane strength.
At 2 p.m. Friday, the storm was located 200 miles southwest of Cuba, according to the National Hurricane Center. The storm is forecast to come closest to South Florida late Saturday night and early Sunday morning — although it will remain well out in the Gulf of Mexico.
Even though South Florida is not in the projected path of Alberto, the region is on the east side — the wettest side — of the storm. South Florida can expect heavy rain, thunderstorms, isolated flooding, strong rip currents and possibly tornadoes, the National Weather Servicesaid.
The “subtropical” designation is a nuance in the world of weather science. Essentially, the characteristics of a subtropical system mean it lacks the punch to quickly increase in strength and become a hurricane.
On its current forecast track, Alberto is expected to continue its slow journey north through the weekend until making a turn to the northwest Monday as it approaches the north-central Gulf coast, the hurricane center said.
Rain chances, as forecast by the National Weather Service, are between 70 and 80 percent throughout the Memorial Day weekend. It’s not until mid-week that the rain chance dips to 40 percent, which is more typical for South Florida’s rainy season.
“Locally heavy rainfall is forecast across western Cuba and over much of Florida and the northern Gulf coast into early next week,” senior hurricane specialist Stacy Stewart said in Friday’s tropical weather outlook.
Portions of South Florida could be put under a flood watch during the weekend because the ground is already saturated from recent rainfall and more tropical moisture is expected, the weather service said.
“Most areas will see between 3 and 5 inches of rain during this period, but the western portions of South Florida could see amounts of up to 7 inches,” NWS meteorologist Barry Baxter said in a weekend rainfall outlook.