Atlantic Hurricane Season Underway: Gaston Strengthens as Fiona Weakens

With Atlantic Hurricane season underway, tropical storm Gaston gains momentum.

— -- Atlantic hurricane season is underway, and this season's seventh tropical storm, Gaston, is gaining strength off the far eastern Atlantic.

Meanwhile, Fiona is barely holding on as a tropical depression as of this morning, moving west-northwest at about 13 mph, according to the National Hurricane Center. Fiona is expected to decrease in forward speed over the next 48 hours.

Gaston has strengthened over the far eastern tropical Atlantic and is expected to become a hurricane by Wednesday, according to the National Hurricane Center. Gaston is moving west-northwest at nearly 20 mph, with a slight decrease in forward speed expected during the next few days.

"Even if it becomes a hurricane, it does not affect land," ABC News meteorologist Ginger Zee said today of Gaston on "Good Morning America."

All eyes are on a third tropical wave over the eastern Caribbean, which has a 60 percent chance of becoming tropical depression or storm in the next 48 hours, she added.