You know the tropics wouldn't stay quiet forever.

Ana, the first tropical storm of the 2009 hurricane season, formed early Saturday morning, while a strengthening depression just behind it turned into Tropical Storm Bill by 5 p.m.

South Florida sits in the middle of the National Hurricane Center's initial forecast tracks for Ana and Bill, but, with both systems more than 2,000 miles and five or more days away, they could go anywhere from Cuba to South Carolina.

``We want people to watch the tropics, but we don't want them to push the panic button,'' said Dennis Feltgen, a spokesman for the National Hurricane Center in West Miami-Dade County.

Of the two storms, forecasters believe Bill appeared to have the better shot of becoming a hurricane.

``Bill already has better structure in its development phase than Ana ever did,'' Feltgen said.

The Hurricane Center's latest advisory Saturday showed Bill moving westward at 16 mph with sustained winds of 40 mph. Forecasters expected it to top 39 mph tropical storm status within 24 hours and to continue strengthening.

By Thursday, when it is expected to near Puerto Rico on its current track, it is forecast to be a hurricane, possibly reaching Category 3 power with winds topping 111 mph.

Tropical Storm Ana, which formed after a weak depression regenerated, was moving quickly westward at 17 mph with sustained winds of 40 mph. Its movement late Saturday prompted forecasters to issue a tropical storm watch for he Leeward Islands, though the storm was more than 800 miles away.

Ana was encountering some upper-level winds and pockets of dry air that could sap its strength.

It was forecast remain a tropical storm through Thursday, when it could be near the coast of Florida, but forecasters weren't ruling out that itcould become a hurricane as well.

Feltgen cautioned that tracks five days out or more have broad margins of error and the storm could shift north or south by hundreds of miles.

He also stressed that meteorologists still struggle with accurately predicting long-range storm intensity and that both systems could eventually prove considerably weaker -- or stronger -- than current forecasts.