A terrifying shelf cloud recently appeared in Uttarakhand’s Haridwar.
About Shelf Cloud:
- A “shelf cloud” or “Arcus cloud” generally forms along the leading edge of thunderstorms.
- It is a type of low-lying, horizontal cloud formation characterized by a clearly defined line of solid clouds.
- It is known for its distinctive wedge-shaped formation. They usually appear as a broad arc across the sky that can sometimes appear to be rotating horizontally.
- Shelf clouds form when cold and dense air is forced into a warmer air mass by wind.
- This rush of cold air often occurs in a thunderstorm’s downdraught, where cold air rushes towards the ground before spreading out to create a gust front.
- Shelf clouds produced by thunderstorms are always preceded by a rush of dry and cold air ahead of the cloud, with rain arriving after the shelf cloud has passed overhead.
What is a Thunderstorm?
- A thunderstorm is a rain shower during which you hear thunder. Since thunder comes from lightning, all thunderstorms have lightning.
- Thunderstorms form when warm, moist air rises into cold air.
- The warm air becomes cooler, which causes moisture, called water vapor, to form small water droplets — a process called condensation.
- The cooled air drops lower in the atmosphere, warms, and rises again.
- This circuit of rising and falling air is called a convection cell.
- If this happens a small amount, a cloud will form. If this happens with large amounts of air and moisture, a thunderstorm can form.
Q1) What is an Air Mass?
Air mass, in meteorology, is a large body of air having nearly uniform conditions of temperature and humidity at any given level of altitude. Such a mass has distinct boundaries and may extend hundreds or thousands of kilometers horizontally and sometimes as high as the top of the troposphere (about 10–18 km [6–11 miles] above the Earth’s surface).