Often, downbursts or downdrafts coming out of a thunderstorm are invisible, especially if it is a dry downburst. This weather phenomenon in the dissipating stage of a thunderstorm can be deadly if the wind direction suddenly changes and affects the direction of spread of a wildfire.
The video above is of a wet downburst. That and the time lapse feature make it possible to clearly see the air and the rain descending, reaching the ground, and then spreading out. Firefighters need to be aware that this is not a rare occurrence and it can affect the wind direction miles away from the cloud.
Wikipedia has more information about downbursts.
