Ides of March
A cocktail of weather phenomena is causing freak rains in March. Scientists have no clue why
THE SIGHT of wheat, mustard, gram and fenugreek crops spread over 10 hectares (ha) would fill Vidyadhar Olkha’s heart with joy. It was end of February and the crops were almost ready to be harvested. A week later, all he had was a mat of leaves and stalks lying on the ground.The rain and hailstorm in the first week of March destroyed 70 per cent of his crops in Jhunjhunu district of Rajasthan.
Olkha has no idea what brought so much rain this March. Neither do scientists and weather forecasters, who attribute the rain to western disturbances and have different theories on what made the disturbances so severe this year.
Western disturbances are low-pressure areas embedded in the Westerlies, the planetary winds that flow from west to east between 30°-60° latitude. They usually bring mild rain during January-February, which is beneficial to the rabi crop.But in the past few years western disturbances have been linked to disasters. The cloud burst in Leh in 2010, the floods and landslide in Uttarakhand in 2013 and the excessive rain in Jammu and Kashmir in 2014 were all linked to these disturbances.T his year, as per the India Meteorological Department (imd), the average rain received between March 1 and March 18 was 49.2 mm—197 per cent above normal. This caused severe damage to crops in several states of the country. According to a statement by Union agriculture minister Radha Mohan Singh in the Rajya Sabha on March 19, crops in over 5 million hectares have been damaged. But despite the destruction the disturbances have been causing, there have been very few studies to understand them.
Scientists agree that western disturbances are formed naturally. They originate in the Mediterranean region and travel over Iran, Iraq, Afghanistan and Pakistan to enter India loaded with moisture, where the Himalayas obstruct them, causing rain and snow in western Himalayas.The snow adds to the glaciers which provide water to India’s major perennial rivers. But what is it that is making this beneficial weather phenomenon increasingly disastrous?