Water-laden clouds gather over Siliguri. A Telegraph picture

Siliguri, May 17: Blazing sun go away, the rain’s here to stay.

The weatherman at North Bengal University Met Station has detected all the makings of a monsoon, a fortnight ahead of schedule, and says an “induced monsoon” will be the prelude to a “heavy rainy season”.

The induced monsoon will continue for the next 48 hours.

Overcast skies blotting out the sun, a jump in relative humidity, and a dip in the mercury that has taken the temperature to five degrees below normal in the last 72 hours, give credence to the forecast.

Weathermen blame the condition on a “local low depression conjoining its turf with another deep depression hovering over the north of the Bay of Bengal, setting the pre-monsoon condition in sub-Himalayan West Bengal”.

Subir Sarkar, who is in charge of the NBU weather station, said: “Monsoon has arrived 15 days earlier in north Bengal this year, giving rise to the chances of induced rainfall, which is typical to the south west monsoon. Normally, in north Bengal it (monsoon) sets in between the end of May and beginning of June. This is a pre-monsoon condition and the depression will die out within the next 48 hours. Till then this unique condition will prevail.”

Explaining the dynamics of the prevailing condition, Sarkar added: “A strong local low depression had evolved on Saturday. This caused torrential rain in parts of Cooch Behar, Toofangunj, Kumargram and several parts of Assam. The situation aggravated as it touched the axis of another deep depression over the north of the Bay of Bengal, which has its axis at 2 km from the surface. The turf created between the two axes has strengthened the depression, causing rain in many parts of north Bengal including the hills of sub-Himalayan West Bengal since the last three days.”

The depression, he said, is almost spent and moving further north. The rains made the mercury plunge and hover between 25 to 30 degree Celsius which is five degrees below normal.

“The relative humidity, on the other hand, settling between 65 to 92 per cent, five per cent higher, has made the weather sultry,” Sarkar said.

“Once the sky clears the temperature will again shoot up to 35 degrees, which is normal during this time of the year. But the second phase of the monsoon will set in within next week and the region will experience normal to heavy rainfall this season,” Sarkar said.

The prospect of rains drenching the region has come both as good, and bad, news.

The tea industry, reeling from recession and pushed further into misery by a pest infestation, has cheered the prospect.

The rains bring with them the promise of a fruitful second flush, which could go a long way in bailing the industry out of crisis.

For hill residents, on the other hand, the lashing rains bring the threat of landslides and floods.