The high cost of hurricanes in the United States 1:46
(CNN) --
Tropical Storm Lisa, previously considered a disturbance, formed in the Caribbean on Monday, according to the National Hurricane Center (NHC).
Maximum sustained winds are currently nearly 40 mph, with tropical storm-force winds extending about 100 miles from the center, according to a hurricane hunter.
The center of the storm is about 280 km south of Jamaica, where a tropical storm watch is in effect.
Lisa is forecast to gradually strengthen and will likely become a hurricane.
"On the projected track, the center will pass south of Jamaica today, south of the Cayman Islands tomorrow, and approach Central America on Wednesday," the center said.