The sky of San Luis with Mammatus Clouds. "They are formed when the cold air descends and joins the rising warm air, marking the limit between a cool and stable air and a more unstable and warm one. Seeing them is synonymous with being close to a strong s

The sky of San Luis with Mammatus Clouds. "They are formed when the cold air descends and joins the rising warm air, marking the limit between a cool and stable air and a more unstable and warm one. Seeing them is synonymous with being close to a strong s