Even before a nip in the air is being felt properly ahead of the onset of winter, districts of southern Bengal are likely to experience another spell of enhanced rainfall activity during the middle of the ongoing week, weathermen have predicted.

Blame it on a low pressure area formed over north east Bay of Bengal and adjoining Andaman and Nicobar Islands which is subsequently predicted to develop into a deep depression over the next 48 hours, the sudden change in weather would be felt over significant parts of south Bengal, especially the coastal districts, which are likely to receive light to moderate showers from 16-18 November, the regional met office in Calcutta confirmed.

The untimely rains, the Met office stated, accompanied by thunder are likely to be widespread over the districts of North and South 24 Parganas and East Midnapore, at a few places over Calcutta, Howrah, Hooghly and West Midnapore and at one or two places over East and West Burdwan, Nadia and Jhargram districts on Thursday and Friday.

Squally wind speed reaching 40-50 kilometers per hour and gusting up to 60 kilometers per hour is likely to be experienced on Thursday morning and is likely to increase to 50-60 kilometers per hour gusting up to 70 kilometers per hour from that evening for the subsequent 24 hours, the IMD communication added.

The Met office has also issued a ‘yellow’ warning of heavy rainfall intensity (7-11 cms) on November 16 at one or two places over North and south 24 Parganas and East Midnapore. That warning gets upgraded to the ‘orange’ band for heavy to very heavy shower intensity (7-20 cms) for Friday at one or two places in North and South 24 Parganas.

Rain warnings for November 16-17 issued by IMD, Calcutta. Twitter/@Indiametdept

As per the trajectory of the weather system foretold by the Met office, the low pressure zone would intensify into a depression over the west-central Bay of Bengal on November 15 and thereafter move northwestwards to intensify into a deep depression off the Andhra Pradesh coast on November 16.

Subsequently, the system would recurve north-northeast wards and reach northwest Bay of Bengal off the Odisha coast on November 17, weather office predicted.

With sea conditions remaining rough to very rough off the Bengal and Bangladesh coasts, a red alert has been issued for fishermen advising total ban on venturing into the sea from November 16-18.