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

A twister is a colloquial term for a tornado—a violently rotating column of air extending from the base of a cumulonimbus cloud to the ground. Characterised by extreme low central pressure and destructive winds, its intensity is measured on the Fujita and Enhanced Fujita (EF) scale.

Drivers of Twister Concentration around the Gulf of Mexico

The vast plains extending north from the Gulf of Mexico, spanning traditional Tornado Alley and Dixie Alley, experience the world's highest twister density, with the United States recording over 1,000 tornadoes a year, due to distinct air-mass dynamics:

Moisture and Heat Source: The Gulf of Mexico, with sea surface temperatures exceeding 26°C, supplies buoyant, moisture-laden maritime tropical (mT) air northward.

Air Mass Collision: The flat terrain of the Great Plains lacks east-west topographic barriers, permitting the unobstructed collision of warm Gulf air with cold, dense continental polar (cP) air descending from Canada and dry air from the Rocky Mountains. This sharp boundary creates severe atmospheric instability.

Jet Stream Dynamics: Strong vertical and horizontal wind shear from the polar jet stream tilts thunderstorm updrafts, generating rotating mesocyclones within parent supercells that spawn tornadoes.

Seasonality and Shifting Patterns: Twisters peak during spring (March to May) when latitudinal temperature gradients are steepest. Recent climatic trends show an eastward shift of high-frequency zones toward the humid Southeast.

Comparative Context and Significance

In contrast, India sees fewer tornadoes—mostly in the pre-monsoon nor'wester (Kalbaisakhi) season over Bengal, Odisha and Bangladesh, such as the 1978 Delhi tornado and Bangladesh's 1989 Daulatpur–Saturia tornado, the deadliest on record—partly because the Himalayan barrier blocks polar air incursions, preventing similar thermodynamic clashes. With climate change intensifying atmospheric instability and moisture fluxes, strengthening Doppler weather radar coverage and impact-based early warning systems is vital for disaster risk reduction.