Derecho Storm

Why in the News?

Recently, some states in the USA were hit by a storm system called a ‘Derecho’.

Key Points:

About Derecho

• The ‘Derecho’ name comes from the Spanish word ‘la derecha’ which means ‘straight’.
• A Derecho, is “a widespread, long-lived, straight-line windstorm” which is associated with a “band of rapidly moving showers or thunderstorms”.
• It is a warm-weather phenomenon.
• For a storm to be classified as a derecho it must have wind gusts of at least 93 km per hour; a wind damage swath extending more than 400 km.
• Severe thunderstorms result in a ‘green sky’ due to light interacting with the huge amount of water they hold.
• They mostly occur across central and eastern parts of the United States.
• They fall into three categories:
  • Progressive
  • Serial
  • Hybrid