Timelapse footage of microbursts causing strong winds at the surface. The microbursts are fast-descending parcels of cold air, which spread out when they reach the ground, causing diverging winds. Here, they are triggered by virga, precipitation that evaporates before it hits the ground. The evaporation cools the air, making it denser, which speeds its fall to the ground. Microbursts pose a severe hazard to aircraft. Filmed in Colorado, USA, in spring.