A western disturbance may increase rainfall over N-W India, which could delay the withdrawal of monsoon
New Delhi: The India Meteorological Department (IMD) has said the withdrawal of monsoons could begin only after 17 September although it has started to show signs of weakening with reduced rainfall over north-western states.
According to the weather department, a western disturbance is likely to increase rainfall activity over north-western India from 13 September, which could further delay its withdrawal.
“Rains are subdued in West and Central India, but there will be enhanced rainfall in north-west due to a western disturbance from 13 September. It will remain so for three days, after which conditions would start developing for its withdrawal. It is likely that the monsoon will not retreat anytime this week,” said Charan Singh, scientist, National Weather Forecasting Centre, IMD.
While the withdrawal of monsoon from North-West India can begin anytime after 1 September, scientists highlight that it was delayed due to a depression over the Bay of Bengal last week, which moved up to Rajasthan and brought rainfall over north-western states.
“Only when there is considerable reduction in moisture content as inferred from satellite images and no possibility of rainfall continuously for at least five days over North-West India, it can be said that the monsoon is set to withdraw. An anti-cyclonic circulation will develop which would indicate that the withdrawal has begun,” said D.S. Pai, head of Climate Prediction Group, IMD.
According to the weather forecast, a low pressure area is likely to develop over North-West Bay of Bengal around 18 September, which would bring rainfall over Odisha, Chhattisgarh and parts of Central and peninsular India. However, intensity of rainfall is not expected to be high and reduce subsequently.
With Jharkhand, west Rajasthan, Gujarat, North-East and parts of Andhra Pradesh and Karnataka still witnessing below normal rains, the overall monsoon deficit of the country stands at 8%. Out of total 36 sub-divisions, as many as 26 have witnessed normal rains, while nine continue to remain rain-deficient and only Kerala has recorded excess rains.
The monthly deficit has increased from 5% in June, to 5.8% in July and 7.6% in August.
According to the weather department, a western disturbance is likely to increase rainfall activity over north-western India from 13 September, which could further delay its withdrawal.
“Rains are subdued in West and Central India, but there will be enhanced rainfall in north-west due to a western disturbance from 13 September. It will remain so for three days, after which conditions would start developing for its withdrawal. It is likely that the monsoon will not retreat anytime this week,” said Charan Singh, scientist, National Weather Forecasting Centre, IMD.
While the withdrawal of monsoon from North-West India can begin anytime after 1 September, scientists highlight that it was delayed due to a depression over the Bay of Bengal last week, which moved up to Rajasthan and brought rainfall over north-western states.
“Only when there is considerable reduction in moisture content as inferred from satellite images and no possibility of rainfall continuously for at least five days over North-West India, it can be said that the monsoon is set to withdraw. An anti-cyclonic circulation will develop which would indicate that the withdrawal has begun,” said D.S. Pai, head of Climate Prediction Group, IMD.
According to the weather forecast, a low pressure area is likely to develop over North-West Bay of Bengal around 18 September, which would bring rainfall over Odisha, Chhattisgarh and parts of Central and peninsular India. However, intensity of rainfall is not expected to be high and reduce subsequently.
With Jharkhand, west Rajasthan, Gujarat, North-East and parts of Andhra Pradesh and Karnataka still witnessing below normal rains, the overall monsoon deficit of the country stands at 8%. Out of total 36 sub-divisions, as many as 26 have witnessed normal rains, while nine continue to remain rain-deficient and only Kerala has recorded excess rains.
The monthly deficit has increased from 5% in June, to 5.8% in July and 7.6% in August.