Southwest monsoon withdraws from India, northeast monsoon rains commence2 min read . Updated: 16 Oct 2019, 06:12 PM IST
Longest delayed withdrawal ever, but southwest monsoon retreated fast
NEW DELHI : The India Meteorological Department (IMD) on Wednesday said the southwest monsoon current has withdrawn from the country, having begun its retreat on 9 October. This could possibly be the fastest withdrawal of the current ever.
Its withdrawal on Wednesday was accompanied by the arrival of the northeast monsoon, which is the primary rainy season for the southern peninsula.
“2019 monsoon season was indeed unique in the way it departed," said K S Hosalikar, deputy director general, Western Region, IMD, “usually it takes around a month for the monsoon to completely withdraw from the country, after it starts retreating from West Rajasthan. However, this year, it not only recorded the longest delayed withdrawal ever, but the process also got completed in just 8-9 days."
The four-month southwest monsoon season is crucial for India, as it accounts for over 75% of the country’s annual rainfall. It determines the agricultural production and thus impacts the economy. Unlike last year, when 9% below normal rains left various parts of the country reeling under droughts, the seasonal rainfall this year was in excess of 10%.
Typically, the current begins withdrawing around 1 September, with the retreat complete by 15 October. This year, though, the retreat began on 9 October, marking the longest ever delay, and was complete by 16 October.
It was also unusual since both the withdrawal of southwest monsoon and arrival of the northeast monsoon took place on the same day – 16 October. Normally, there is a gap of 10 days between the two seasons, subject to inter-annual and inter-seasonal variations.
“We were expecting that since the departure set in late, the entire process will also get completed fast. There was reversal of winds in the lower atmosphere and cessation of rain. The thunder-storm activity over Mumbai also came down to zero in last few days and temperature has also begun to go down. But north-east monsoon also set on the same day, this hasn’t happened in years," said Hosalikar.
Unlike the southwest monsoon which brings rainfall over the entire country, north-east monsoon brings rainfall only over Tamil Nadu, coastal Andhra Pradesh, Rayalseema, Kerala, and south-interior Karnataka during October to December. It is also crucial for cultivation of rabi crops such as wheat.
According to the weather department, the northeast monsoon rains have commenced over Tamil Nadu and adjoining areas of Andhra Pradesh, Karnataka, and Kerala and are likely to continue for the next three to four days.