The India Meteorological Department (IMD) has forecast above-normal rainfall in September following heavy rain in August. The forecast predicts that the overall rainfall for the month is likely to exceed 109% of the long-period average (LPA), which stands at 168mm. The forecast also predicts heavy rain and landslides in specific areas of India due to anticipated low-pressure systems and cyclonic disturbances.
Low-pressure Systems and Cyclonic Disturbances to Drive Rainfall
The IMD anticipates the formation of low-pressure systems nearly every week in September, bringing continuous rainfall to various regions. These systems are expected to cause extremely heavy rain episodes, particularly in the foothills of the Himalayas, encompassing Uttarakhand, Himachal Pradesh, Jammu and Kashmir, Punjab, and Rajasthan. Such heavy rainfall could trigger landslides and floods in these areas, highlighting the need for vigilance and preparedness.
Two Cyclonic Disturbances Predicted for the Coming Week
In the coming week, at least two cyclonic disturbances are predicted to form. One is expected to develop over the Arabian Sea, while the other will emerge over the Bay of Bengal. These disturbances are likely to bring substantial rainfall to parts of India, especially in the regions where they form and as they move westward.
Formation and Movement of Subsequent Systems
The IMD anticipates the formation of two more cyclonic disturbances during the second and third weeks of September. These systems are likely to originate over the Bay of Bengal and subsequently move towards west Uttar Pradesh, bringing rain to the northwest of India. The majority of the systems originating in the Bay of Bengal during this month are predicted to travel northwest, reaching Rajasthan and generating rainfall over northwest India.
Distribution of Rainfall Across India
While the IMD anticipates above-average rainfall for the country as a whole, there are regional variations in rainfall expectations.
Above-Average Rainfall in Northwest India
The northwest region, including Punjab, Haryana, Rajasthan, and Delhi, is likely to witness heavy rain due to the expected influx of low-pressure systems and cyclonic disturbances originating in the Bay of Bengal.
Potential for Landslides and Floods in Himalayan Foothills
The foothills of the Himalayas, especially in Uttarakhand, Himachal Pradesh, and Jammu & Kashmir, are expected to receive extremely heavy rainfall, making them susceptible to landslides and floods. These regions have witnessed severe impacts from rainfall in the past and are again at high risk due to the predicted rainfall patterns.
Below-Average Rainfall in Some Areas
Regions like Rayalseema, southern Karnataka, northern Bihar, northeastern Uttar Pradesh, and parts of northeast India are expected to experience below-average rainfall in September. The reason behind this deviation from the overall trend remains to be investigated by the IMD.
Impact on Temperatures and Overall Monsoon Performance
The IMD forecasts that temperatures will remain above-normal during the day and night across the country. This prediction indicates that while September will experience heightened rainfall, it will not necessarily lead to significant drops in temperature, especially in the daytime hours.
Overall Monsoon Performance Remains Strong
Despite some regional variations, the overall southwest monsoon has performed well so far in 2023. It has exceeded the long-period average (LPA) by 7%, signifying an overall favorable monsoon season.
Past Two Months Show Above-Normal Rainfall
The monsoon strengthened in July and August, delivering above-normal rainfall in these months. August’s rainfall surpassed the IMD’s forecast for normal rainfall, with a 15% excess, highlighting the monsoon’s strong performance in recent months.
Take Away Points
- The India Meteorological Department (IMD) has predicted above-normal rainfall in September, exceeding the long-period average (LPA).
- Multiple low-pressure systems and cyclonic disturbances are expected to form throughout the month, bringing continuous rainfall and potential heavy rain episodes.
- The foothills of the Himalayas, particularly in Uttarakhand, Himachal Pradesh, and Jammu & Kashmir, are at risk of landslides and floods due to expected heavy rainfall.
- Northwest India, including Punjab, Haryana, Rajasthan, and Delhi, is likely to receive heavy rainfall, while certain parts of the south and northeast may see below-average rainfall.
- Temperatures are expected to remain above-normal, with no significant cooling expected despite the high rainfall.
- The southwest monsoon has performed well in 2023, exceeding the LPA and displaying above-normal rainfall in July and August.
