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Context: The Mainaguri area of Jalpaiguri district in West Bengal was hit by a devastating tornado on March 31, 2024. Even though they are not common in India, tornadoes have been happening more frequently recently, which has made disaster management and mitigation more difficult.

Details

• Traditionally, tornadoes in India have been more common in the eastern states like West Bengal, Odisha, and Jharkhand, primarily during the pre-monsoon season. While rare, there's evidence of tornadoes in northwest India as well.
• India lacks an official system to monitor tornadoes, although the IMD documented the recent Jalpaiguri event.

Climate Change Connection

• Experts believe a warming Bay of Bengal, rising land temperatures, and unusual wind patterns might be contributing to more frequent and stronger tornadoes in India.
• Warming Waters: The Bay of Bengal's rising temperatures can increase atmospheric moisture, a key ingredient for tornadoes. Warmer seas can also fuel more powerful storms, which can spawn tornadoes.
• Hotter Landmass: A warming landmass can contribute to greater instability in the atmosphere, another factor influencing tornado formation. Rising temperatures can create pockets of hot air that rise quickly, creating a spinning motion that can lead to a tornado.
• Shifting Winds: Unusually strong or persistent wind patterns can provide the necessary "twist" to initiate the rotation that leads to a tornado. Changes in wind patterns can also alter the ingredients needed for tornado formation, such as by bringing in more moisture from the ocean.
• Favourable Conditions: Warm air, humidity, and specific wind patterns create a favourable environment for tornadoes to form. India's landmass typically disrupts strong tornadoes, but changing wind patterns might be altering this. Weaker winds can allow tornadoes to persist for longer periods, increasing the potential for damage.

About Tornado Formation

• Tornadoes are violently rotating columns of air that form from thunderstorms and reach the ground. They are nature's most violent storms and can cause fatalities and devastate entire neighbourhoods in seconds.
• Winds within tornadoes can reach speeds of up to 300 miles per hour, with a damage path exceeding one mile wide and 50 miles long.
• Tornadoes form when warm, moist air collides with cool, dry air in the presence of a low-pressure system like a trough. This creates instability in the atmosphere, which leads to the formation of thunderstorms.
• Tornadoes can occur anywhere in the world where thunderstorms form, but they are most common in the mid-latitudes (between 20 and 60 degrees north and south). In these regions, cold polar air masses often meet warm tropical air masses, creating the ideal conditions for severe thunderstorms and tornadoes.
• The United States experiences the most tornadoes globally, particularly in the central and southeastern regions known as Tornado Alley. Other countries with a high frequency of tornadoes include Argentina, Bangladesh, and Australia.
• The Enhanced Fujita scale (EF-scale) is used to measure tornado strength. This scale assigns a rating to a tornado based on the estimated wind speeds and the amount of damage caused. The EF scale ranges from EF0 (weakest) to EF5 (strongest).

Conclusion

• The Jalpaiguri tornado raises concerns about a potential rise in tornado activity in India. Climate change and its influence on wind patterns might be a contributing factor. Further research and improved monitoring systems are crucial to understand and prepare for this potential threat.

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