Bay of Bengal system to enhance monsoon activity in India
What's the story
A new weather system is developing over the Bay of Bengal, promising a fresh spell of monsoon rainfall for east and central India. Satellite imagery is showing an active weather system developing over the Bay of Bengal, which could significantly impact the Southwest Monsoon over the next week to 10 days. The development of this system is linked to a long zone of atmospheric convergence from the Bay of Bengal to the western Pacific.
Weather systems
Convergence zones are crucial for low-pressure system formation
Convergence zones are vital for organized weather systems as they combine moisture-laden winds, creating conditions conducive for low-pressure systems.
Several such systems are likely to form along this convergence zone and head westward toward central India in the next five to seven days.
These systems could bring widespread showers to eastern and central India, improving rainfall in areas that have been deficient during this monsoon season.
Critical period
Importance of early September for monsoon
The first half of September is crucial for India's overall monsoon performance.
Rainfall during this time can greatly affect the final seasonal figures, with forecasts indicating a possible swing of around 5% above or below current levels based on monsoon activity.
Thus far, the 2026 Southwest Monsoon has seen an uneven distribution of rainfall across India.
Rainfall distribution
Rainfall distribution across Indian states
Ladakh is the biggest rainfall surplus region with 204% above normal rainfall. Dadra and Nagar Haveli and Daman and Diu follow with a 51% surplus, while Odisha has recorded 25% excess rainfall.
Delhi too has received 18% more rain than usual. However, several states are facing major seasonal deficits.
Meghalaya has seen the sharpest shortfall at 58% below normal, followed by Manipur (minus 43%) and Bihar (minus 42%).
Arunachal Pradesh and Andhra Pradesh are both around 40% below normal.
Seasonal deficit
Monsoon so far and forecasts
So far, India has received 587.8mm of rainfall against a normal of 679.5mm, resulting in a seasonal deficit of 13%.
Despite this shortfall, the monsoon is still within the India Meteorological Department's normal rainfall category.
The developing systems over the Bay of Bengal and expected rains in early September could be crucial in shaping how the 2026 monsoon season concludes.