Throwing tsampa (barley flour) in the air is a common Buddhist ritual in Tibet. It is the mark of joy and offering, expressing the good wishes for your own and others happiness. It is usually accompanied by chanting verses expressing the desire for overcoming all obstacles.
An annual event, the Yarkyi Festival celebrates the foundation of Tibetan Institute of Performing Arts (TIPA). It is normally held in August. The 3 day long celebration consists of TIPA teams competing against each other in song and dance contests.
www.tibetanarts.org/