Atlantic Storm May Gain Tropical Traits Offshore of US East Coast

A broad area of showers and thunderstorms currently brewing just off the Carolina coast will cause stormy seas in the western Atlantic and could develop tropical characteristics into next week.

The feature closest to the United States could join two other active tropical depressions in the Atlantic: Nine and Ten.

The system contains a copious amount of tropical moisture, some of which is the remnants of Tropical Storm Grace. The combination of Grace's moisture and a non-tropical system unloaded 6 inches of rain and gusty thunderstorms on parts of the Florida Peninsula over the past week.

According to AccuWeather Hurricane Expert Dan Kottlowski, "The system just offshore will struggle with strong wind shear at first, but if the shear was to relax, it could evolve into an organized tropical system over time."

Wind shear is the change in direction and speed of air currents through different layers of the atmosphere. Little or no wind shear is needed for a tropical system to develop.

Regardless as to whether or not the system develops tropically, it will stir up the ocean from Bermuda to part of the U.S. coast into next week.

Seas and surf will build from the Florida Peninsula to the Delmarva Peninsula through Sunday. The number and strength of rip currents will increase. Occasionally, some of these areas will also be swiped by drenching downpours.

Bathers and boaters enjoying the last few days of the official summer season will need to exercise caution and heed advisories as they are issued. Many of the beaches will not have lifeguards on duty, since Labor Day has passed.

According to Senior Meteorologist Brett Anderson, "The combination of increasing winds and building seas will likely have an impact on cruise ships traveling from the East Coast ports to Bermuda and the Bahamas Saturday into at least Monday."

"Make sure you take along sea sickness medication," Anderson said.

How rough conditions get will be dependent upon the strength of the system and how long it lingers over the same part of the Atlantic.

A steady drift to the northeast would allow conditions to improve along the southern and mid-Atlantic coast of the U.S. early next week.

There is a chance the system stalls or is drawn northward. If the system stalls, then seas could remain rough through much of the week. If the latter occurs, showers and stormy seas could reach the coastal areas of the Northeast U.S. and part of Atlantic Canada next week.

"The biggest deterrent to tropical development in the Atlantic basin this season has been widespread wind shear," Kottlowski said.

Even if central Atlantic Tropical Depression Nine and Tropical Depression Ten develop into the season's next tropical storms, both are likely to remain well east of the Lesser Antilles.

While wind shear will likely remain a major deterrent through the end of the 2015 Atlantic hurricane season, there is still the potential for multiple systems to develop in a less hostile zone as the typical formation areas shift toward the southwestern part of the basin.

The area from the western Caribbean and the Gulf of Mexico to the western Atlantic will remain an area to watch for both tropical and non-tropical storm development, as well as potential impact to populated areas into October.

Remember that a storm does not have to be fully tropical in nature to cause major disruptions to travel and to threaten lives and property.