After a short period of relief, lasting only a week, Kolkatans and residents of south Bengal are witnessing yet another wave of hot and humid weather.

The Regional Meteorological Centre (RMC) has given a forecast of the day temperature in larger parts of south Bengal, including Kolkata seeing a surge again in the next six days.

Within a gap of one week, the weather office has issued a second ‘yellow alert’ (for heat wave) in 10 districts and its indirect impact on the remaining parts of south Bengal till 19 April.

According to the weather department, the day temperature in the Gangetic West Bengal region is to see a rise by 2-4 degrees Celsius in the next 4-5 days. While the mercury in the western districts could shoot through 40 degrees Celsius, Kolkata could also feel the heat of around 39 degrees. As pointed out by a weather scientist at the RMC Kolkata, the surge in the day temperatures, touching 39 degrees, is anticipated to start from tomorrow and see a continuous rise till the next few days till 20 April.

Till Saturday, Kolkata, along with the adjoining districts of South 24-Parganas, North 24-Parganas, Howrah, Hooghly, East Midnapore are tipped to have hot and discomforting weather. A worse weather condition of heatwave is anticipated to grip the western districts of West Midnapore, Jhargram, Purulia, Bankura, Birbhum, Murshidabad, East Burdwan, West Burdwan and South 24-Parganas and East Midnapore, till 19 April.

Notably, for a heat wave, conditions like the maximum temperature rising by 4.5 degrees above normal and over 40 degrees Celsius are required. Considering the fact, the ten districts of south Bengal have also been issued a ‘yellow alert’ of heatwave from 17-19 April by the weather office. Even if these conditions are unlikely to prevail in Kolkata during the alert period, the city is anticipated to experience the impact of the heat wave in the western districts, according to weather officials.

The factors responsible for the ongoing heat, according to the weather scientists, is the prevailing of mainly dry westerly to north westerly winds over the region. Also, absence of any trough lines or western disturbance in the path on one side, while inadequate moisture incursion from Bay of Bengal for cloud formation on the other side, are tipped to bring the anticipated hot and discomfort weather in the south Bengal region. As Kolkata is close to coastal districts, the humidity during the period is expected to go higher.

Even after 20 April, there is hardly any chance of a significant change in the day temperatures,” informed a weather department official. “Some parts of south Bengal might get drizzles but that would not be significant and would be triggered by local clouds,” added the scientist.