Kolkata: In a twist of weather, May turns cooler, wetter than April so far – Times of India

KOLKATA: After a 61-day dry spell that lasted till the end of April, the city has received eight thunderstorms and 194.5mm rain this month, which is 211% higher than normal. May, so far, has also been cooler than April that saw maximum temperature touch 39.6°C on April 24 while the mercury remained above 35°C on 13 days.
The maximum temperature has touched 35°C on four days so far between May 1 and 18. On Wednesday, the city recorded a maximum temperature of 34.4°C.
South Bengal, too, has received 97% excess rain in May, though it was lashed by several thunderstorms in April even as the city remained dry till April 29. According to the Regional Meteorological Centre (RMC), lack of moisture inflow had dried up thunderstorms in April, making the mercury rise.
“Scorching northwesterly winds had neutralized the weak southeasterly winds from the Bay of Bengal that had not been carrying enough moisture. Once it started gaining strength at the end of April, thunderstorms started hitting Kolkata regularly,” said RMC director GK Das.
With cyclone Asani forming over South Andaman Sea and then approaching the eastern coast, further moisture and cloud incursion helped in raising the frequency of thunderstorms in south Bengal and Kolkata. Eventually, clouds breaking off from the outer band of the cyclone floated into Kolkata and south Bengal, triggering thunderstorms and rain.
“Generally, Kolkata receives more thunderstorms in May than April. But this year, there was none till the end of April, which was unusual. We expect more thunderstorms over the next few days since moisture incursion is on. It should help to keep the mercury lower, on an average, than April,” said Das.
A twenty-year analysis of the city’s weather puts the average April mean temperature (maximum) at 30.2°C. It rises to 30.7°C in May, which is the hottest month of the year.
“But over the last few years, we have seen a reversal of this trend. Since 2016, mean temperature has often been higher in April than May. This has happened largely due to more thunderstorms in May, which has pulled the mercury down. It has been the same this time,” said a weather expert.A temperature of around 40 degrees in the Chota Nagpur Plateau region is a pre-requisite for thundershower.