The tornado that hit Bara and Parsa districts on March 31 raises a big and unavoidable question: is the weather of Nepal becoming more extreme? The northern states of India as well as Bangladesh have faced several tornadoes over the years. But according to Department of Hydrology and Meteorology in Kathmandu, it’s the first real tornado to ever hit Nepal.
Fierce and destructive winds are nothing new to Bara and Parsa districts or to most other parts of the country. The pre-monsoon period in spring usually brings hail and thunderstorms that can be destructive enough. But with windspeed of up to 200 km/h, the tornado that whirled through Bara and Parsa covering a 200-250 metres wide belt was more devastating.
The video below shows a tornado hitting a village in Faridabad, northern India, just two months earlier, and gives an idea of what it might have felt like in Bara and Parsa. In the affected villages in the two districts, locals are still reeling from the impact: 28 people lost their lives, over 600 people were injured, and at least a thousand homes were utterly destroyed.
Tornados, hail and thunderstorms as well as sandstorms have marred states across northern India for ages, but these weather phenomena are said to have become more frequent and fiercer than just a few decades ago. Last year, dust storms alone killed over a 100 people in Uttar Pradesh and Rajastan, and lightning during thunder storms claimed many lives, too.
The map below shows the localities where lightning has been the most severe over a fifteen year period. In Nepal, thunder storms, often coupled with extreme hail storms featuring hail as big as golf balls, cause destruction and kills scores of people every year. In fact, Nepal has one of the highest incidents of fatalities due to lightning in the world! But is it getting worse?
Last year, headlines such as the following hit the news in India: “India’s new reality: More frequent and severe dust storms.” The experience in India this year is no different as several powerful dust storms and tornados have hit the northern belt. Weather scientists seem to agree on the cause: higher-than-average temperatures generate fiercer pre-monsoon storms.
Every year during the pre-monsoon period from March through May, humid easterly winds from the Bay of Bengal, and humid westerly winds in some cases, collide with the warmer air inland. As these two weather systems clash, and warmer air races into the cooler humid air above, powerful hail and thunder storms form and bombard villages with hail and lightning.
The issue is that with every increase in average temperature in the region, evaporation from the sea inevitably increases, and this produces even more humid winds that collide with still warmer air inland. The result is unforgiving: even more unstable weather conditions, which can indeed create not only hail, thunder and dust storms but also devastating tornados.
The map below shows the distribution and intensity of dust storms over northern India last year. It also illustrates how close these extreme weather conditions – generating such powerful winds – are to Nepal. Will a one or two degrees higher average temperature send these weather systems further north to reach Terai districts like Bara and Parsa in future?
In Nepal, Director General of the Department of Hydrology and Meteorology, Saraju K. Vaidya, says in wake of the tornado in Bara and Parsa that, “with climate change these [tornados] may become more frequent, and we have to prepared by upgrading forecasting and computer modelling capacity.” As the climate is getting warmer, extreme weather phenomena like tornados might begin to reach further north from the belt across northern India into Nepal.
Is it time for Nepal to start preparing for more extreme weather, then? Well, in Bara and Parsa relief is more urgent than preparation. But it seems crucial to take precautions. In Bangladesh and Orissa in India, shelters have reduced fatalities from cyclones by more than 90 pct. Raising awareness on how to react when a thunderstorm or tornado starts to form may save lives, too. Indeed, considering how to prepare the local people might be a more than timely task.