The National Hurricane Center on Monday was closely tracking and monitoring two tropical disturbances.

NHC issued an advisory in the 4 p.m. hour Monday, for Tropical Storm Don, the fourth named storm of the 2017 hurricane season.

An Air Force Reserve reconnaissance aircraft investigating the area of low pressure located east-southeast of the Windward Islands has found a small, but well-defined surface circulation and a small area of tropical storm force winds over the eastern semicircle of the circulation.

There is a tropical storm warning in effect for Grenada.

A Tropical Storm Watch is in effect for Barbados, St. Vincent and the Grenadines, and St. Lucia.

Tropical Storm Don was centered 485 miles east of Trinidad, but is expected to dissipate within 72 hours.

The second area of disturbed water is located about 875 west-southwest of the Cabo Verde Islands.

“Some gradual development of this system is possible over the next few days while it moves slowly toward the west-northwest or northwest over the open Atlantic Ocean,” NHC’s Daniel Brown said. “Formation chance through 48 hours is 20 percent and increases to 30 percent over the next five days.”

It’s still too early to tell what, if any, impact either storm would have on the U.S. Mainland.