What is a twister? Why are the majority of twisters observed in areas around the Gulf of Mexico? (Answer in 250 words)

Introduction

A twister is a tornado: a violently rotating, narrow column of air extending from a cumulonimbus cloud to the ground.

Formation

• Warm, moist surface air rises beneath cooler, drier air, creating strong instability.
• Vertical wind shear makes horizontal air rotate; powerful updrafts tilt and stretch this rotation vertically.
• Supercell thunderstorms with mesocyclones can concentrate rotation into a tornado, producing extreme winds and damage.

Why around the Gulf of Mexico?

• The warm Gulf supplies abundant moisture and latent heat to the southern United States.
• Cold, dry continental or Canadian air can meet warm moist Gulf air along fronts, creating sharp instability.
• The Rocky Mountains and Great Plains channel contrasting air masses and support strong low-level and upper-level wind shear.
• Jet-stream dynamics and a broad, flat landscape favour storm development and observation.

Context

Tornadoes also occur elsewhere, but the United States records many because of favourable geography, dense observation networks and reporting capacity. Early warning, storm shelters and resilient construction reduce mortality.

Keywords: tornado, supercell, mesocyclone, instability, wind shear, latent heat.