Unprecedented Heavy Rains in North India Decoded!
India recently experienced an increase in monsoon rainfall, causing a 2% increase in rainfall across the country on July 9. This increase in rainfall can be attributed to an interaction between a western disturbance and the monsoon trough. Unfortunately, this heavy rainfall has led to severe consequences, including landslides, flash floods, and extensive damage to highways and infrastructure in Himachal Pradesh, Uttarakhand, Punjab, and Haryana.
Previously, India experienced a 10% deficiency in rainfall until the end of June. However, the monsoon’s surge along the west coast and parts of northern India in the past week helped to compensate for this deficit, resulting in the 2% excess rainfall on July 9, as reported by the India Meteorological Department. The distribution of rainfall across different regions varies, with northwest India witnessing a 59% excess, central India experiencing a 4% excess, peninsular India facing a 23% deficiency, and east and northeast India encountering a 17% deficiency.
Several areas in Haryana, Punjab, and other regions recorded record-breaking rainfall, with Chandigarh receiving 32 cm, Ambala 22 cm, Delhi 15 cm, Nangal 28 cm, and Ropar 27 cm of rainfall between Saturday and Sunday. Himachal Pradesh’s Bhuntar and Mandi recorded 10 cm and 8 cm of rain respectively. The rainfall in Himachal Pradesh was exceptionally high, with 103.8 mm recorded, compared to the normal 8 mm, resulting in a staggering 1,193% excess rainfall. Similarly, Punjab witnessed 57.5 mm of rainfall against the normal 4.6 mm, making it a 1,151% excess for the day.
According to M Mohapatra, the director-general of the meteorology bureau, the significant rainfall can be linked to the combination of a western disturbance and the monsoon. According to him, this interaction resulted in heavy to extremely heavy rainfall in Jammu and Kashmir, Himachal Pradesh, north Punjab and Haryana, and Uttarakhand. The forecast had predicted good rainfall in July, helping to cover the previous rainfall deficit. Over the past nine days, rainfall has been 24% in excess for the July period. However, the weather bureau expects the rainfall to gradually reduce in the coming days.
Climate scientists have drawn attention to the similarities between the recent floods in Himachal Pradesh and the devastating 2013 floods in Uttarakhand. They highlight the active monsoon, strong low-level easterly winds bringing abundant moisture, and upper-level divergence due to an eastward-moving through as contributing factors. These synoptic conditions are predictable, emphasizing the importance of improving forewarning systems and mitigation strategies. Climate change has impacted the monsoon, causing intense rainfall with shorter durations but much heavier downpours.
The intense rainfall is expected to persist for at least the next 24 hours in Himachal Pradesh, Uttarakhand, and the northwestern plains. It will gradually reduce thereafter but is likely to continue in Uttarakhand, Uttar Pradesh, and parts of Bihar. The monsoon trough is shifting towards the Indo-Gangetic Plains. Mahesh Palawat, a vice president at Skymet Weather Services, a private forecaster, predicts that normal rainfall spells will continue over northwest India following the current intense spell caused by the interaction between the western disturbance and the monsoon trough.
According to Roxy Mathew Koll, a climate scientist at the Indian Institute of Tropical Meteorology, hilly areas such as the Himalayan foothills and the Western Ghats are particularly susceptible to heavy rains and landslides due to global warming. The extra moisture in the atmosphere interacts with the hills, leading to orographic lifting and resulting in heavy rainfall. He further emphasizes the need to closely monitor flash floods caused by cloudbursts and extreme rainfall, identifying vulnerable areas, and utilizing radar systems to improve forecasting. However, the lead time for such events with radar is limited to approximately three hours. It is also essential to assess the impact of land use changes and development activities on aggravating flash floods.
In the forecast, the meteorological department predicts widespread rainfall with isolated heavy to very heavy rainfall in various regions, including the Western Himalayan Region, Punjab, Haryana-Chandigarh-Delhi, Rajasthan, and Uttar Pradesh. Uttarakhand, Himachal Pradesh, and adjoining districts of Punjab and Haryana-Chandigarh are expected to experience isolated extremely heavy rainfall on July 9. Additionally, isolated heavy to very heavy rainfall is likely to occur in Uttar Pradesh from July 10 to 13. Other regions across India can expect varying degrees of rainfall over the next few days.
In conclusion, India has witnessed a surge in monsoon rainfall, leading to excess rainfall across the country. The heavy rainfall resulted in landslides, flash floods, and damage to infrastructure in several regions. The interaction between a western disturbance and the monsoon played a significant role in the increased rainfall. Climate scientists highlight the impact of climate change on the monsoon, emphasizing the need for improved forecasting and mitigation measures. The forecast predicts continued rainfall in various regions, with specific areas expected to experience heavy to very heavy rainfall.