64kmph squall brings relief after scorching day in Kolkata

KOLKATA: A squall hit Kolkata with a wind speed of 64 km/hr early on Friday evening, pulling the mercury down by 4.5°C and reducing humidity by a considerable 21%. It brought relief at the end of a scorching summer day, during which the maximum temperature had soared to 37.1°C.

The squall — that had been predicted on Wednesday — was triggered by a low-pressure trough that extended from Bihar to the north-east across south Bengal. This was the season’s sixth squall and the first in May, but caused only a light drizzle. The weekend, however, could be a wet one, said officials at the Regional Meteorological Centre.




“The conditions had been turning favourable for a squall in Kolkata since Wednesday. There was enough moisture-incursion from the sea and heating in the Chhotanagpur area. To add to these, we had two low-pressure troughs in the region over the last 48 hours. The one on Thursday had triggered storms across several neighbouring districts but the clouds had disintegrated by the time they reached Kolkata. On Thursday, however, the squall hit the city with great intensity,” said G K Das, director of RMC.

The highest wind speed recorded during a squall this season was 98km/hr on April 17. It had been preceded by another squall the same evening that struck with a wind speed of 82km/hr. To qualify as a squall, a thunderstorm must be accompanied by wind at the speed of at least 45km/hr, which has to last a minute.

“On Thursday, the squall hit Kolkata from a north-westerly direction and lasted a minute. So, it was a squall, as well as a nor’wester,” added Das.

On an average, Kolkata receives about a dozen squalls between March and May. This year, apart from the squalls, the city has been lashed by eight thunderstorms that have kept the mercury in check. The highest maximum temperature recorded this season has been 37.6°C. Even though this was the first one this the month, thunderstorms should continue in May. But in case they disappear, the temperature may shoot up.

“The conditions, however, remain favourable and a lot of moisture is flowing in from the sea. While the conditions are pushing the humidity up and making it uncomfortable, they are also raising the chances of thunderstorms,” added Das.

The city could receive rain on Saturday and could be lashed by another thunderstorm on Sunday.