Atlantic Invest 99L Likely to Become a Tropical Depression or Storm This Weekend

Chris Dolce
Published: August 12, 2017

A tropical disturbance we've been tracking in the Atlantic since last week could become this season's next tropical depression or storm tonight or on Sunday.

Dubbed Invest 99L, this system has become a little better defined and the shower and thunderstorm activity has increased somewhat, as of Saturday afternoon, about 250 miles northeast of the Turks and Caicos Islands. The term "invest" is used by the National Hurricane Center (NHC) to identify features that are being monitored for possible development into a tropical depression or tropical storm.

(MORE: Invest Explained)

The next named storm that forms in the Atlantic would be Gert.


Atlantic Area to Watch

Invest 99L's environment is improving a bit, with less wind shear and dry air, but these conditions near a fledgling disturbance may still be a challenge to overcome even if it becomes a tropical depression or storm. 

(MORE: Hurricane Central)

The NHC says that this system has a high chance of development during the next two days.

So, if a tropical cyclone develops, how strong will it get and is it anything to worry about on the East Coast?

This system will begin to turn more to the north this weekend east of the U.S. That is because it will be sandwiched between the western periphery of high pressure in the central Atlantic and an incoming southward dip in the jet stream across the eastern U.S.


Steering This Weekend

Invest 99L will take the alleyway in between those large-scale weather systems.

At the moment, it appears this alleyway will set up far enough east that the U.S. would avoid any direct impacts, but increased surf along the east coast is possible. 

For now, the majority of our forecast guidance does not spin up 99L strongly before it is whisked out to sea early next week. It would appear a tropical storm would be the peak potential of this system.

Check back with us at weather.com for the latest on this, and everything in the tropics this hurricane season.


The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

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