Massive Shelf Clouds Formation | 14 Jul 2023

Source: TH

Why in News?

Recently, a massive Shelf Cloud formation has been spotted in Haridwar, Uttarakhand.

What are Shelf Clouds?

• About:
  • Shelf clouds - also known as Arcus clouds - are often associated with powerful storm systems, and many times they are reported as wall clouds, funnel clouds, or rotation.
  • These clouds are sometimes seen beneath cumulonimbus clouds, the dense, towering vertical cloud that causes intense rain.
  • They often appear ahead of powerful Thunderstorms with heavy rain, strong winds, and occasionally hail or tornadoes.
• Formation:
  • When a cold downdraft from a cumulonimbus cloud reaches the ground, the cold air may spread rapidly along the ground, pushing existing warm moist air upwards.
  • As the cold air descends, it pushes warm air upward, causing condensation and cloud formation. This process creates the distinct horizontal shape and appearance of a shelf cloud.

What are the Types of Clouds?

• High Clouds:
  • Cirrus Clouds: Cirrus clouds are high-altitude clouds that appear wispy, feathery, and white. They are composed of ice crystals and are often associated with fair weather.
    • Cirrus clouds can cause halo, a ring around the sun or the moon.
  • Cirrocumulus Clouds: High-altitude clouds that appear as small, white, and fluffy cloud patches. They often have a wavy or honeycomb-like pattern.
  • Cirrostratus Clouds: High-altitude clouds that form a thin, whitish veil covering the sky. They can produce halos around the sun or moon.
• Middle Clouds:
  • Altocumulus Clouds: Mid-level clouds that form white or gray patches or layers. They often have a wavy or lumpy appearance.
  • Altostratus Clouds: Mid-level clouds that create a uniform, gray or bluish-gray layer covering the sky. They are thicker and denser than cirrostratus clouds and can lead to light precipitation.
• Low Clouds:
  • Cumulus Clouds: Cumulus clouds are fluffy, white clouds with a flat base and a rounded top. They are typically formed by rising warm air currents and are often seen on sunny days. Cumulus clouds can develop into cumulonimbus clouds, which are associated with thunderstorms.
  • Stratus Clouds: Stratus clouds are low-level clouds that appear as a uniform grayish layer covering the sky. They often bring drizzle or light precipitation and can create a dull, overcast appearance.
  • Stratocumulus Clouds: Low-level clouds with a patchy appearance, often appearing as rounded masses. They can be white or gray and cover a significant portion of the sky.
  • Nimbostratus Clouds: Thick, dark, and featureless clouds that cover the sky. They bring continuous precipitation, often lasting for an extended period.
• Clouds that exhibit Significant Vertical Development:
  • Cumulonimbus Clouds: Large, towering clouds associated with thunderstorms. They have a dark base and can reach high altitudes, producing heavy rain, lightning, and strong winds.