Southwest Monsoon Season Concludes with Notable Rainfall Variations Across India
The Southwest monsoon season officially wrapped up on Tuesday, with the India Meteorological Department (IMD) reporting a significant 7.9% excess rainfall compared to the long-period average (LPA). This year’s monsoon has been marked by stark regional disparities, with some areas experiencing record rainfall while others faced severe deficiencies.
Record Rainfall in Northwest India
According to the IMD, northwest India recorded an impressive 747.9 mm of rainfall this season, marking the highest levels since 2001 and the sixth highest since records began in 1901. This surge in precipitation has been a boon for agriculture in the region, which relies heavily on monsoon rains for crop production. In contrast, the eastern and northeastern parts of the country faced a different reality, experiencing the second lowest rainfall since 1901.
Post-Monsoon Forecast: Mixed Bag Ahead
Looking forward, the IMD has projected that most regions will receive normal to above-normal rainfall during the post-monsoon season, which spans from October to December. However, exceptions exist, particularly in parts of northwest India and some areas in the extreme southern peninsula and northeastern regions, where below-normal rainfall is anticipated.
In October, the IMD forecasts normal to below-normal maximum temperatures across most of the country, with the exception of northeastern and adjoining eastern India, as well as the Western Himalayan states. Notably, there is a high probability of above-normal maximum temperatures in northeastern India, which could have implications for local agriculture and weather patterns.
Seasonal Rainfall Insights
The IMD’s data indicates that the seasonal rainfall from June to September was above normal, recorded at 107.9% of LPA. This translates to a total of 937.2 mm of rainfall, making it the fifth highest since 2001 and the 38th highest since 1901. The distribution of rainfall was uneven, with northwest India experiencing a 27.3% excess, while central India saw a 15.1% increase. Conversely, the east and northeast regions suffered a 20.3% deficiency.
The monsoon’s early arrival this year was noteworthy, as it advanced over the South Andaman Sea and Nicobar Islands on May 13, nearly nine days ahead of schedule. It reached Kerala by May 24, well before the usual onset date of June 1, and covered the entire country by June 29.
Delayed Withdrawal of the Monsoon
The withdrawal of the southwest monsoon is expected to be delayed due to a well-marked low-pressure area over the Gulf of Kutch. M. Mohapatra, the director general of IMD, indicated that the withdrawal process would likely commence around October 9, following a week of continued rainfall in various regions.
La Niña Conditions on the Horizon
Adding another layer of complexity to the weather patterns, Mohapatra noted that sea surface temperatures in the equatorial Pacific are nearing La Niña thresholds. La Niña, characterized by the cooling of ocean surface temperatures, typically brings about climate impacts that are opposite to those of El Niño, particularly in tropical regions. This could lead to below-normal maximum temperatures across several parts of India during the post-monsoon season.
Extreme Weather Events and Their Impact
The monsoon season has not been without its challenges. Tragically, at least 1,528 lives were lost due to various weather-related incidents, including heavy rain, flash floods, lightning, and thunderstorms. The states most affected included Himachal Pradesh, Jammu and Kashmir, and Madhya Pradesh, where the toll was particularly high.
September was marked by extreme weather events, including heavy rainfall and cloudbursts in Chennai, as well as significant rainfall in Telangana and Uttarakhand. The IMD reported an extreme rainfall event in Kolkata, where 251.4 mm fell within a 24-hour period, approaching cloudburst thresholds.
Conclusion
As the monsoon season concludes, India faces a complex weather landscape characterized by both excess and deficiency in rainfall across different regions. The IMD’s forecasts for the post-monsoon period suggest a continuation of this variability, with potential implications for agriculture, water resources, and disaster management. The anticipated La Niña conditions may further influence weather patterns, making it crucial for policymakers and farmers to stay informed and prepared for the challenges ahead.
