The season’s first Nor’wester stuck Calcutta at 62kmph on Saturday.
At least one more squall is due in Calcutta in a day or two, said a Met official.
Saturday’s storm, which brought relief to a parched city, began around 9.30pm. The peak wind speed was recorded around 9.40pm, said a Met official. At Dum Dum, the peak wind speed was 46kmph around 9.40pm, he said.
At Dum Dum, the peak wind speed was 46kmph, around the same time.
Light rain followed the strong gusts of wind, accompanied by streaks of lightning. The IPL match at the Eden Gardens had to be called off for the storm.
On Sunday, the minimum temperature was 23.6 degrees, almost three notches below normal. Excessive humidity had pushed the minimum temperature up to around 29 degrees, where it had remained for the past couple of days. On Saturday, it was 28.3 degrees, two notches warmer than usual.
The effect of the storm was hard to miss. Many ran for the terrace or balcony to get a touch of the cool winds. The tap water, usually warm even in the night, turned cold almost instantaneously.
On Sunday, the early morning was pleasant. The sun came out as the day progressed, and it was still very hot. But the conditions were not half as uncomfortable as they had been for the past few days.
In Met parlance, a Nor’wester is a squall that originates over the heated Chhotanagpur plateau in the late afternoon and sweeps through parts of eastern India over the next three to five hours at a wind speed of over 45kmph. It is usually followed by a brief spell of rain.
On Saturday, the western districts of Bengal, like Bankura, Jhargram, Purulia, West Midnapore and West Burdwan were lashed by thunderstorms from late afternoon. The Met office had issued the first nowcast (a forecast that is expected almost immediately) alerts for Jhargram, Purulia and Bankura around 4pm.
“The rain-bearing clouds moved towards the coast. The conditions were perfect for the clouds to grow in size and gain momentum as they moved towards the coast. There was enough moisture, a suitable wind pattern, atmospheric instability, and a lifting mechanism for the clouds to rise,” said H.R. Biswas, head of the weather section at the Regional Meteorological Centre in Alipore.
Along with Calcutta, North and South 24-Parganas,Howrah and Hooghly were also struck by thunderstorms
“Favourable wind pattern and moisture incursion from the Bay of Bengal” has prompted the Met office to predict thunderstorms across Bengal over the next few days. Thunderstorms are expected across south Bengal till April 30. Calcutta can look forward to at least another spell by Tuesday, said a Met official. The day temperature is likely to gradually drop by “three to five degrees,” the Met bulletin said.
“On Monday, heavy rain is expected in East Burdwan and West Midnapore districts. Thunderstorms with gusty winds (60-70kmph) and lightning are likely in Purulia, Bankura, East and West Burdwan, Jhargram, West Midnapore and Hooghly. The remaining districts, including Calcutta, are likely to get rain with gusts clocking around 50kmph,” said a Met official.