A freakish hailstorm in Moran town of Dibrugarh district in Assam December 27, 2022 left the town covered with hail and what appeared like snow. More than 4,000 houses in the town were damaged by the storm and Rabi crops were affected.
Videos and photos circulating on social media captioned the deposits on the roads and houses as snowfall, but the truth is far from it. The deposits are of hail that accompanied a storm that was a bit unexpected at this time of the year, according to experts.
“Some of the hail has not formed completely because of the sudden nature of the event and therefore, it is soft and flaky like snow. But this is definitely not snowfall,” Partha Jyoti Das, head of the water, climate and hazards division of non-profit Aaranyak based in Guwahati, Assam, told Down To Earth.
“If we look at the climatology of the last 30 years, such an event happening in December is rare,” said Ranjan Phukan, scientist at the India Meteorological Department, Pune.
Such events become more common in February and thereafter, bringing pre-monsoon rainfall with them, according to Phukan.
The role of climate change in the occurrence of such events and if their frequency would increase in the future is difficult to ascertain. Many factors would need to be studied for that.
Partha Jyoti Das, head of the water, climate and hazards division, Aaranyak
Such hailstorm events were also witnessed in Shillong, Guwahati and some other places in Assam in December 2021. At the time, many people had thought it to be snowfall.
The current hailstorm has occurred due to the interaction of two weather systems.
“The first is a low-level moisture incursion from the Bay of Bengal. The second is a low-pressure trough, which is a remnant of a western disturbance that has travelled from northwest India,” Sunit Das, scientist at IMD’s regional centre in Guwahati, told DTE.
Western disturbances, which are extra-tropical storms that travel from the Mediterranean towards Pakistan and India during winter and spring months, have not been very common in December.
The first one affected northwest India only December 24. A remnant of this could have caused the hailstorm event.
The freezing level, the level in the atmosphere where the temperature drops to zero, was also at a lower level at three kilometres, which aided the hail formation, as per Sunit.
“The role of climate change in the occurrence of such events and if their frequency would increase in the future is difficult to ascertain. Many factors would need to be studied for that,” Partha said.
This study would need to be done as the region’s farmers must adapt to such events. Though assessments are still being done, many farmers would have lost their Rabi crop in this hailstorm.
“Farmers in the region usually grow vegetables at this time of the year and that can get impacted by such events,” Partha said.