Monsoon is inching towards Bengal, the Met office said on Monday, when high humidity tormented Calcuttans.

“The southwest monsoon has advanced to Bengal’s doorstep. It is likely to reach north Bengal in a couple of days and south Bengal soon after,” said H.R. Biswas, head of the Regional Meteorological Centre in Alipore.

The monsoon winds reach Bengal via the Northeast.

The usual onset date for north Bengal is June 5, and south Bengal is June 10.

The northern limit of the monsoon currently passes through Lamding in Assam, according to a Met bulletin issued on Monday.

“Conditions are favourable for further advance of the southwest monsoon into some more parts of central Arabian Sea, Maharashtra, Karnataka, Telangana, Andhra Pradesh, remaining parts of Tamil Nadu and the southwest Bay of Bengal, some more parts of the westcentral and northwest Bay of Bengal, some parts of Chhattisgarh, Odisha, Bengal and Sikkim, and remaining parts of the northeastern states during the next 2-3 days,” the Met bulletin said.

A trough runs from east Bihar to the northwest Bay of Bengal across Gangetic West Bengal in lower tropospheric level, said the bulletin.

Once monsoon covers the entire country, the trough is called the monsoon trough — an imaginary line that connects the low-pressure points from west to east of the country.

High humidity

Calcuttans suffered one of the most oppressive days of this summer on Monday.

A powerful thunderstorm struck the city on Sunday afternoon. As a result, the
minimum temperature, recorded just before sunrise, was 23.5° Celsius, almost four notches below what is normal for early June.

But as the day progressed, high humidity played the perfect villain.

At 35.4° Celsius, the maximum was normal. But the relative humidity ranged between 62 and 97%. It means the moisture content was above 75% for a better part of the
day.

The discomfort index was high even after sundown.

Around 5.30pm, the temperature was around 35° Celsius in central Calcutta, as recorded by a private forecasting agency. But the RealFeel was as high as 47° Celsius.

Spending five minutes outdoors was a challenge.

Storm in districts

Districts like East Burdwan, Hooghly and North 24- Parganas got localised thunderstorms on Monday evening.

“Another spell of thunderstorm is likely in Calcutta by Wednesday,” said a Met official in Alipore.

Heat and humidity are two central ingredients for the formation of rain-bearing thunderclouds.

“Isolated to scattered rainfall is likely over the Gangetic West Bengal during June 8, 9, 13 and 14,” the Met bulletin said.

Rain meeting

A monsoon preparedness meeting was held on Monday by the Kolkata Municipal Corporation commissioner, attended by councillors from Boroughs I to VII and officials from the PWD and irrigation department.

The councillors flagged some issues that need redress that included removing loose and dangling wires, said sources.

The civic body will conduct a thorough inspection of the city over the next two days, they said.