With massive wildfires, large amounts of energy and heat drift upwards, creating a smoke plume. When there’s enough moisture in the atmosphere, the smoke plume condenses to form a cloud. When pyrocumulonimbus clouds form above fires, they can create winds that cause the blaze below to spread even faster and develop a more unpredictable pattern. Earlier this week, French authorities reported their first pyrocumulonimbus cloud, which appeared near Bordeaux. The European Centre for Medium-Range Weather Forecasts has not yet confirmed whether this was in fact France’s first pyrocumulonimbus, CNN reported.