– The effect of the slide in temperature will be felt after sundown, said the Met official
Debraj Mitra/Pradip Sanyal: The minimum temperature dropped five degrees to settle at 17.3 degrees Celsius on Friday in what the Met office said was the last lap of winter.
Saturday is likely to see the Celsius drop further to around 15 degrees, according to the forecast.
The last time the Celsius was under 15 degrees in Calcutta was 14.2 degrees on January 27.
“The hint of chill is likely to persist for around three days. After that, the moisture incursion will increase again. There is a strong possibility of another slide in the Celsius from February 15 to 20. But the Celsius is not expected to slide to 15 degrees in that spell. In that sense, the current cold spell is likely to be the last for this winter,” said a Met official.
The minimum relative humidity — a measure of the moisture content in the atmosphere during the driest part of the day — was around 30 per cent on Friday. The low moisture content paved the way for the movement of northwesterly winds.
Despite the minimum sliding five notches, barring the early morning, the weather was at best pleasant for most of the day. It was almost impossible to wear warm clothes under the afternoon sun.
“That is because of the rising day temperature. The days are becoming longer. The sun is becoming stronger,” said the official.
The maximum temperature was around 30 degrees on Thursday. It dropped slightly on Friday. But the effect of the maximum temperature is felt for a longer period than that of the minimum temperature.
The effect of the slide in temperature will be felt after sundown, said the Met official.
This winter has been one of the warmest in recent years. The coldest day was January 11, with a minimum temperature of 12.3 degrees.
Successive western disturbances have changed the wind patterns, leading to moisture-laden winds from the Bay invading the lower levels of the atmosphere, thereby stalling the flow of cold northwesterly winds.
The same northwesterly and northerly winds are now dominating the lower atmosphere.
Another western disturbance is likely to emerge around February 12-13. Under its indirect impact, the wind pattern is likely to change. Anticyclonic winds are likely to bring in moisture from the Bay. But the situation will change again from February 14-15.
