Weathermen decode Indian hailstorm mystery

PUNE: The unprecedented hailstorms that caused severe damage to life and crops in many states in the country in February and March, is still a puzzle for the weather scientists, who say, this kind of event has not been officially recorded in the history.

The weather scientists measure rainfall, temperature, humidity etc. However, in India, there is no method to measure hailstorm. Calling it a type 1 hailstorm, to differentiate it from the usual hailstorm (type 2) that Indians are used to during pre-monsoon season, scientists at the Indian Institute of Tropical Meteorology (IITM), Pune are studying the possible causes.

JR Kulkarni, senior scientists at IITM said: "The recent hailstorms are associated with the unusually downward shift of the westerlies to 15 degree north latitude as against their normal position at 30 degree north. The excessive snowfall that happened in many countries in the world is also associated with the downward shift of the westerlies."

The recent hailstorms are different from the normal pre-monsoon hailstorm in their frequency, size, duration of fall and melting time. The pre-monsoon hailstorms occur usually in the evening while the type 1 hailstorm took place all through the day.

Type 1 hailstorm lasted for 10 minutes to 40 minutes as against 5-10 minutes in type 2. "The shifting of the high pressure area, which usually lies over land in central India, towards east coast, where it picked up moisture, is what caused the hails. But we are yet to study why the high pressure area shifted towards the east," said Kulkarni.