Lance races in California

"I've decided to ride the Tour of California in 2010," the American told Twitter.

Current Tour of California champion Levi Leipheimer will be joining Armstrong in the newly formed Team RadioShack.

The race will be held from May 16-23, so riders can expect balmy weather, a marked change from the wet, chilly conditions that prevailed for much of this year's race in February.

For the first time the event will begin with a road stage, from Nevada City, California, to the state capital of Sacramento.

It will pass through Davis, Santa Rosa, San Francisco, Santa Cruz, San Jose, Modesto, Visalia, Bakersfield, Pasadena, Big Bear Lake, Los Angeles and end in the Los Angeles suburb of Thousand Oaks, home of title sponsor Amgen.

Stage seven will be the individual time trial in downtown Los Angeles next to the Staples Center arena - home of the Los Angeles Lakers basketball team.

"For the 2010 Tour of California we had the unique opportunity to move our race to a part of the year when we are almost guaranteed great weather in California," said Andrew Messick, president of AEG Sports.

"This timing will help us to better showcase the beautiful features the state of California has to offer, while allowing us to travel to parts of the state that just weren't feasible in previous years."

Organizers said the use of Twitter to announce the schedule was a first for an event of this stature.

Twitter was much in evidence in the 2009 edition of the race, as Armstrong mobilized his army of followers on the networking site to be on the lookout for his stolen time trial bike, which was eventually turned in to police in Sacramento.