Monsoon likely to begin withdrawing from west Rajasthan Monday onwards
Widespread and heavy rain will continue in parts of Bihar, sub-Himalayan West Bengal and some northeastern states till September 26Updated: Sep 24, 2020, 16:39 IST
Monsoon is likely to begin withdrawing from west Rajasthan Monday onwards, India Meteorological Department said on Thursday. It’s been delayed by a week compared to the normal date for commencement of monsoon withdrawal, they added.
Widespread and heavy rain will continue in parts of Bihar, sub-Himalayan West Bengal and some northeastern states till September 26.
The hot and humid conditions are also likely to reduce thereafter. “We are expecting rainfall to stop and moisture to reduce from next week because the low-pressure area over east Uttar Pradesh is likely to move further east. We don’t see the possibility of the development of any other system which could bring rain next week to the northwestern region,” said K Sathi Devi, head, National Weather Forecasting Centre. Northwest India has a 15% rain deficiency as on Thursday since June 1; Delhi has a 19% rain deficiency.
Also Read: Delhi sees driest September in 16 years
This year, monsoon rain over the country is 9% in excess as on Thursday.
The monsoon season will officially end on September 30, but for IMD to declare commencement of monsoon withdrawal, rain should stop completely; water vapour should reduce and an anti-cyclonic wind pattern should be established, according to Sathi Devi.
In September, northwest India recorded a 46.8% rain deficiency while south peninsula received 67.7% surplus rain; east and northeast India received 12.8% surplus rain; central India recorded a 6.1% rain deficiency.
A low pressure area is lying over central parts of east Uttar Pradesh. It is likely to move east-northeastwards towards Bihar in the next three days. There is likely to be convergence of strong moist southerly/southwesterly winds from Bay of Bengal over northeast and adjoining east India till September 26.
There is a trough (area of low pressure) from north Madhya Maharashtra to the cyclonic circulation associated with low-pressure area over central parts of east Uttar Pradesh.
Under the influence of the above systems, widespread and very heavy rain is likely over Arunachal Pradesh, Assam, Meghalaya, sub-Himalayan West Bengal, Sikkim, Bihar and east Uttar Pradesh on September 24 and 25.
Extremely heavy rain is also very likely over Bihar and east Uttar Pradesh on September 24; over Arunachal Pradesh and Assam and Meghalaya on September 24 and 25.
In UP, Azamgarh recorded 30 cm of rain; Siddharthnagar 26 cm; Turtipar 20 cm; Jaunpur 18 cm; and Cherrapunji in Meghalaya recorded 27 cm between Wednesday morning and Thursday morning.
The normal date for commencement of monsoon withdrawal from northwest India is September 17 and for complete withdrawal from the country is October 15, as per the new monsoon onset and withdrawal dates issued by IMD in April this year. Until last year, the normal dates for the commencement of withdrawal were September 1 and October 15 for complete withdrawal. The new onset dates are based on monsoon data from 1961 to 2019 and withdrawal dates are based on data from 1971 to 2019 analysed by scientists in IMD, Pune.
Last year, the monsoon started withdrawing only on October 9 against the normal date of September 1 and prolonged rains brought a deluge to parts of Maharashtra, Kerala and Bihar in August when rainfall usually reduces. Monsoon withdrew completely only by October 17.
In September, the country is 0.6% rain deficient. Since June 1, the country has experienced 8.1% excess rain, according to the IMD.