TAMPA, Fla. (WFLA) — The National Hurricane Center is keeping an eye on a disturbance that has a 90% chance of formation and will likely become Tropical Storm Lee.

The NHC said showers and thunderstorms associated with an area of low pressure are located over the central tropical Atlantic about 900 miles west-southwest of Cape Verde.

Forecasters believe a tropical depression or tropical storm could form in the next day or so as the system moves toward the west-northwest at 15 to 20 mph.

The NHC said the system will likely become Tropical Storm Lee. It could strengthen into a hurricane later this week as it nears the northern Leeward Islands.

The NHC is also tracking a strong tropical wave that is forecast to move off the coast of West Africa on Tuesday.

Once the wave moves offshore, the NHC said a tropical depression could form over the far eastern tropical Atlantic during the middle to the latter part of the week.

The system is expected to move across Cape Verde on Wednesday night and Thursday. It has a 70% chance of formation over the next seven days.

The NHC also said Post-Tropical Cyclone Franklin “could acquire some subtropical or tropical characteristics late this week or this weekend while it moves erratically between the Azores and Portugal.”

The system, which was once Hurricane Franklin, has a 20% chance of forming over the next seven days.