Multiple Storm Cloud Behavior (image) University of Copenhagen Share Print E-Mail Caption In an area with more clouds, the colder, denser air under them, caused by the rainfall, extends downwards and outwards from the cloud. A gust front is formed, and collides with fronts from other clouds. The air is subsequently forced upwards, and a new cloud is formed by the rising air. Credit Søren Granat Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.