As the heavy, dark cloud crept ever closer, Musa Rahmitulla's family knew he would not be coming home that night.
Musa, 51, is weather modification expert based in Zhaosu, a county in northwest China's Xinjiang Uygur Autonomous Region, which borders Kazakhstan. Over the past 30 years, he has spent every rainy season observing the sky and loading his hail cannon with silver iodine-packed shells to disrupt unfavorable weather fronts.
The rugged topography of Zhaosu, Musa's hometown, is known for the, often, disastrous effects of its weather system. To protect the region's productive farmland, from late May to late October, the rainy season, Musa and his 84 coworkers man the meteorological front line.
Musa retired from the Army 30 years ago. In his words, weather modification is just another kind of battle, "To win the battle, you have to be experienced."
"There are so many variables -- wind direction, the thickness of the cloud, and most importantly, timing," he says, adding that his cannon is often loaded and ready to be discharged before the storm arrives. "If you leave it too late it is less effective," he says.
Sometimes, experience is more useful than technical devices. On one afternoon in late July, Musa fired 120 shells at a cloud formation despite the fact that the weather modification department deemed the cloud "no big deal" based on radar data.
"I could sense the seriousness just from the way the clouds had accumulated mass, not to mention the accompanying lightning," he recalled.
Thanks to Musa's trigger-happy decision, the hail only damaged around 35 percent of the wheat yield of 20 hectares. "If he had not acted in time, the consequences would have been much worse," says Wang Wei, head of Qagan Usu township.
Not every team member is as experienced as Musa. Keen to make a life change, he quit weather modification to take up farming in 2001. His replacement made a disastrous misjudgment, leading to a storm that decimated 4,000 hectares of farmland.
"After such huge losses, the farmers petitioned the township government, calling for Musa to be reinstated," Wang recalled.
Cloud seeding and hail management is dull and lonely work. For much of the summer and fall, the region's most beautiful seasons, Musa and his colleagues are stationed in fields. They stand like sentinels; alone, watching and guarding around the clock.
It is also a dangerous profession. In 2011, Musa fractured his left foot after his 60-kg loader fell while he was maintaining his cannon. Around three years ago, another cannon operator in a neighboring township was killed while he was trying to dislodge a shell out of a cannon.
Yu Jianbin, director of Zhaosu County weather modification office, explained that the county has 17 cannons and 32 rocket launchers distributed at 19 stations across 60,000 hectares of farmland. "Whatever devices we possess, our canon operator's experience is the most valued item in our arsenal," he said.
Among the 11 cannon operators in Qagan Usu, only three, Musa and his two apprentices, have more than 10 years of experience.
"Operators come and go, they struggle with the isolation and low pay," says Wang. Each operator earns around 3,000 yuan (450 U.S. dollars) for each of the five rainy months every year.
Being a cannon operator is more than just a job, with it comes great responsibilities.
"Our split second decisions can affect the lives of many families," he says. "I won't allow our mistakes to ruin people's lives."