Updated

Tropical Storm Sandy is concerning weather experts as it looms in the Caribbean and threatens to head north, possibly slamming the East Coast with high winds and rain.

The National Hurricane Center in Miami said Sandy was about 395 miles south of Kingston, Jamaica, and had winds of 40 mph. It is expected to head toward Jamaica and be near or over the island Wednesday.

The system could be near hurricane strength of 74 mph as it approaches Jamaica.

It's the third year in a row that the Atlantic basin has had at least 18 named storms, a higher than average year of about 11.

Forming in the central Caribbean Monday, Tropical Depression 18 developed into Tropical Storm Sandy on Tuesday. Storm experts there say Sandy will likely then head north by Thursday, potentially causing major flooding across Jamaica, Hispaniola, the Bahamas and eastern Cuba.

It’s unclear now how threatening Sandy will be come Friday, because its path depends on several weather factors, but there is potential for a “tropical nightmare,” AccuWeather.com reports.

The storm could ruin some weekend plans for East Coast residents from Florida to the Carolinas, before being drawn inland to the mid-Atlantic or New England states early next week. While the Southeast coast might be dealing with heavy rains, forceful winds and rough surf, areas from Virginia to Maine could be at even greater risk. In the worst-case scenario, the storm could pack high winds and dump rain, possibly causing widespread flooding and a significant storm surge northeast of its center.

AccuWeather.com says this impending weather is “reminiscent of the Perfect Storm,” and could even create heavy snow in the Appalachian Mountains, on the future storm’s western side.

While this pattern is threatening, it’s also possible that the jet stream will sweep east quickly enough to offer the East Coast protection from Sandy, and the system might head for Bermuda.

It’s also conceivable that the East Coast could avoid a direct hit and Sandy could just graze the coastline, with limited negative impact.

Sandy’s strength and path are uncertain, but weather experts recommend communities from Florida to the Northeast monitor it closely.

To track the storm click on MyFoxHurricane.com.

The Associated Press contributed to this report.