NEW ORLEANS (AP) — Clarinetist Pete Fountain, dressed in a tunic as one of King Arthur's knights, looked frail but happy Tuesday morning as he led 100 members of his Half-Fast Walking Club onto Uptown streets in what has become New Orleans' unofficial opening of Mardi Gras.

''Oh, I'm feeling fine. You always feel fine on Mardi Gras,'' said Fountain, 77. He's had health problems since Hurricane Katrina, but still plays two days a week at a Gulf Coast casino.

Mardi Gras — Fat Tuesday — is the often raucous end to the pre-Lenten Carnival season. The celebration characterized by family friendly parades uptown and in the suburbs — and by heavy drinking and lots of near-nudity in the French Quarter — is highlighted by 12 days of parades and parties.

This year's Half-Fast walk, with the theme ''Knights of the Round Table,'' was the 47th for Fountain's club. Several members wiped sweat from their foreheads in unusually warm, muggy weather, with temperatures already in the upper 70s.

Temperatures were expected to rise to about the record of 81 degrees in New Orleans, an indicator that flesh-flashing in the bawdy French Quarter was likely to be greater the usual.

Crowds started forming near dawn in the Quarter and some people had not yet had any sleep after Monday night's reveling. Police reported no unusual incidents.

While the walking club was on its way, floats of the Zulu parade headed for their starting point. Zulu, the black community's oldest parade, was to be followed by the Rex parade, with businessman John E. Koerner III reigning as Rex, King of Carnival and Monarch of Merriment.

Rex would be followed by hundreds of gaily decorated truck floats, many created by families and neighborhood Carnival clubs. Police expected the last floats wouldn't reach the end of the parade routes until late afternoon.

In suburban Jefferson Parish and elsewhere in south Louisiana, revelers lined up on parade routes or set up family picnics.