Extreme weather patterns wreak havoc in India

From the third driest June in 54 years to the rainiest September in 102 years, the monsoon season in India has wreaked havoc across the country. Though last week was the official conclusion of the Indian monsoon, the wettest monsoon in 25 years has toppled several records.

According to experts, India received 968.3 mm rainfall from June 1 to September 30 – the official start and end dates of the monsoon season. The India Meteorological Department (IMD) records show that this was the rainiest monsoon in the last 25 years. It was only in 1994 that India recorded more average monsoon rainfall (1001 mm) than this year.

The IMD has said that the monsoon retreat is expected to begin on October 10. This will be the latest ever retreat of a monsoon. The previous latest retreat was recorded in 1961 when the monsoon retreat began on October 1.

Experts feel that climate change may have a role to play in these increasing extremes. The overall rainfall was almost 10% excess compared to the normal levels. This is considering that the start of monsoon was one of the driest in recent history (with 33% deficit).Struggling against a dry June, the surplus rainfall in July and August helped overcome the deficit. However, it was in September that the monsoon moved into the excess category. From September 1 to 30, India has received an average of 259.3 mm rainfall, which is the highest since 1917 and second highest in recorded history.

Union Home Ministry officials have said that nearly 1,900 people have lost their lives and another 46 were reported missing this monsoon season in rains and floods which affected more than 25 lakh people in 22 states. Huge numbers have been moved into relief camps and crops have been devastated as well.

Rains have continued past the end of season in many parts of the country. As per IMD records, Madhya Pradesh received more rainfall than ever in recorded history since 1901. The total rainfall here was 1383 mm – which is 61% more than the normal. East Rajasthan also recorded 53% excess rainfall at 919.5 mm. This is the second rainiest monsoon year for eastern Rajasthan. In the central region, Saurashtra and Kutch also witnessed a maximum of 66% excess rainfall this season. Down South, Hyderabad has received a record amount of rain last month – the most in over 100 years

There have been repeated low-pressure systems from the Bay of Bengal that have prevailed for longer than normal periods over central India. The resulting moist westerly winds drenched Konkan and Goa region as well as the mountain sections in Madhya Pradesh. Konkan and Goa also received highest-ever rainfall on record this year with a total accumulation of 4385.8 mm – 53% above average. Central Maharashtra also recorded second-highest rainfall on record with a total of 1167 mm.

According to the Weather Channel, Mumbai witnessed five ‘extremely heavy rain/ days when the rainfall crossed over 204 mm within 24 hours. Since 2009 to 2018, Mumbai had witnessed only eight such instances over ten years.

Adding that 2019 has been an unpredictable monsoon from the get-go, the Weather Channel points out that it arrived a week late in Kerala, remained stalled in June, causing a 33% deficit, and then saw a surge in July, August and September. As on September 29, 2019, the all-India realized rainfall is 9% over the long-term average.

Recent IMD data reveals that one of the strongest positive Indian Ocean Dipole (IOD) was recorded this year. The IOD is said to be in a positive phase if the western part of the Indian Ocean is warmer than normal. The strength of the IOD is measured by the IOD index. If the index crosses +0.4°C, it is considered positive, and this year, the IOD index crossed +1.7°C.Research has shown that a positive IOD (+IOD) has been associated with higher monsoon rainfall in many parts of India, especially in central India.

However, there are two sides to a coin as always. Recorded data also shows that certain parts of North and East India got below-average rainfall. This includes the union territory of Jammu-Kashmir, the Haryana-Delhi-Chandigarh region, and states like Uttarakhand, eastern Uttar Pradesh, West Bengal, Jharkhand and Manipur. With a 56% shortfall in rain, Manipur remained the driest state in the country this year, ahead of Haryana (-42%) and Delhi (-35%).