Yasothon - Salvos of homemade rockets blasted into the sky amid thumping dance music, mud-wrestling and monks as Thailand's northeast hailed the start of the crucial monsoon season over the weekend.Every year devotees from the rural Isaan region fire rockets to remind the gods to bring the rains, a traditional merit-making ritual that draws locals and tourists alike to the culturally distinct region.On the outskirts of the town of Yasothon on Saturday, hundreds of revellers looked on as teams of rocket-builders competed with each other to see whose missile would fly the farthest.Throughout the day dozens of homemade rockets were strapped to a large wooden launch pad and sent towards the heavens, accompanied by cheers, dancing and much drinking.The festival is fiercely competitive. Each group builds and finances its own rockets while judges assess them against a string of criteria - from how dramatically they take off and how far they fly to the aesthetic qualities of the smoke trails they leave behind."It's really good fun, really exciting, really interesting, well worth a visit," said Alan, a tourist from Britain, as a rocket careered overhead. "You have everyone from teenage kids to parents and grandparents out here," added Grace Moore, an American from Seattle.Away from the launch pads the celebration had something of a music festival vibe with live music stages, plenty of booze and revellers wrestling in the mud.But the festival, which is also celebrated in neighbouring Laos, has a serious side. Thailand's northeast - the country's poorest and most populous region - is hugely reliant on farming and especially on rice.It has suffered two years of drought. There are high hopes this year's monsoon will bring enough water to make up for the recent shortfalls, although the rockets failed on Saturday to jog the gods' memories.The region is also a stronghold of the democratically elected government that was forced out of power by the military in 2014.The junta has strengthened the military's presence there, knowing many in Isaan seethe with resentment towards the army and the military's supporters among Bangkok's wealthy elite.