The National Hurricane Center currently is tracking two tropical waves in the Atlantic basin, which covers the northern Atlantic, Gulf and Caribbean, along with the one expected to move off Africa. ➤ September hurricane season forecast: Savor the break, but trouble is brewing in back half

The National Hurricane Center currently is tracking two tropical waves in the Atlantic basin, which covers the northern Atlantic, Gulf and Caribbean. ➤ September hurricane season forecast: Savor the break, but trouble is brewing in back half

A tropical wave has been designated as Invest 91L. It's likely to become a tropical depression by the weekend.

The National Hurricane Center plotted the disturbance on its seven-day tropical weather outlook on Sept. 10. It is forecast to see some slow development over the next week.

Invests run from 90 to 99, followed by a letter: L for the Atlantic basin and E for those in the eastern Pacific. After 99, it starts over again and the next invest would be 90.

The National Hurricane Center is tracking two systems in the Atlantic basin, including a new one moving into the Gulf.

Activity is expected to ramp up, and a disturbance in the eastern Atlantic is likely to become a tropical depression later this week or weekend, according to the National Hurricane Center. AccuWeather forecasters are predicting it could become Tropical Storm Gabrielle before the weekend and could even become a hurricane by the end of the weekend.

Tropical Storm Fernand is not expected to pose a threat to Florida or the U.S. as it moves north over the central Atlantic. Invest 99L has a low chance for development as it moves over the Windward Islands. There is a low risk of tropical development late ...

The Atlantic basin includes the northern Atlantic Ocean, Caribbean Sea and Gulf of America, as the Gulf of Mexico is now known in the U.S. per an order from President Trump. NOAA and the National Hurricane Center are now using Gulf of America on its maps and in its advisories.