Bow Echo Latest News
A series of intense storms recently swept across Delhi, forming a distinctive crescent-shaped weather pattern known as a “bow echo” —a term used by meteorologists to describe such arch-like storm systems.
Understanding Bow Echoes
A bow echo is a storm system that appears as a bowed line on radar imagery, often part of a larger squall line. These systems typically span 20–100 kilometers and persist for 3–6 hours . The term was introduced in the 1970s by Japanese-American meteorologist Ted Fujita , renowned for developing the tornado classification scale.
Formation Mechanism
- Rain-Cooled Air Descent : As precipitation falls, it cools the surrounding air, which then sinks and spreads horizontally upon reaching the ground.
- Gust Front Creation : This cooled air forms a boundary (gust front) that lifts warm, moist air ahead of it, triggering new thunderstorms.
- Sustained Cycle : The resulting thunderstorms generate more rain-cooled air, reinforcing the gust front’s strength. Over time, air inflow on the storm line’s trailing edge causes the system to curve into a bow shape.
Historical Context
Bow echoes are not uncommon in North India. In 2022 , a similar event struck Delhi and Noida, though it was short-lived (lasting an hour) and produced winds up to 100 km/h .
Key Characteristics
- Wind Damage : Associated with straight-line winds capable of causing widespread destruction.
- Duration : Typically persists for 3–6 hours, though some systems (like derechos) can last much longer.
- Geographical Scope : Often observed in regions prone to intense convective activity, such as the Indo-Gangetic plains.
Frequently Asked Questions (FAQs)
Q1: What is a derecho?
A: A derecho is a widespread, long-lasting windstorm linked to rapidly moving thunderstorms, often producing destructive gusts over vast areas.
Q2: What are the primary types of bow echo formations?
A: Bow echoes can develop through three initial patterns:
- Disorganized thunderstorm cells ,
- Mature squall lines , and
- Supercell thunderstorms .
