Rain and storm on Met radar

Pedestrians run for shelter at Esplanade during Sunday evening’s rain. Picture by Sanjoy Chattopadhyaya

TT, March 19: The city received rain this evening after a week following the formation of a cyclonic circulation over north Bengal, which has also created conditions favourable for a thunderstorm tomorrow.

The rain was caused by multiple clusters of cloud which formed over the western districts of south Bengal and moved towards Bangladesh and the Bay of Bengal.

The skies darkened around 5.30pm as the cumulonimbus clouds blocked out the setting sun but what followed was a spell of light rain accompanied by a cool breeze, instead of a thunderstorm that is common after similar build-ups in summer.

North Calcutta received more rain than the south as the clouds were positioned just north of the city.

The Alipore Met office recorded traces of rain till 8.30pm.

"The clouds were scattered and brought rain to most south Bengal districts between afternoon and evening," a weather department official said.

Digha, where radar pictures showed 16km-tall clouds had formed, experienced a hailstorm.

"Rainfall is expected in Calcutta and other parts of south Bengal, especially the ones near the Bay of Bengal coast, tomorrow. After that the skies will begin to clear and the day temperature will rise slowly," said Sanjib Bandyopadhyay, deputy director general, India Meteorological Department, Calcutta.

A thunderstorm is likely tomorrow because of excessive moisture in the atmosphere, a Met scientist said. According to meteorologists, a thunderstorm is rain caused by tall cumulonimbus clouds and often accompanied by strong winds.

Sunday's maximum temperature was 33.7 degrees Celsius, a notch below normal. It is likely to fall to around 31 degrees because of the rain but start rising again from Tuesday, reaching 35 degrees by midweek.

The minimum temperature, meteorologists said, may drop slightly after Monday as the North Wind is likely to gain in strength.

"There is, however, little chance of the mercury dropping below 20 degrees Celsius," a Met official said.

During the last wet spell, from March 8 and 12, the city had received 181.7mm of rain, which was more than the rainfall the Alipore Met office had recorded in the entire month in the past decade.