Understanding the Current 'Break'
The Southwest Monsoon has gone quiet over large parts of the country, a phenomenon often described as a 'break' or 'lull' in monsoon activity. The India Meteorological Department (IMD) has noted that rainfall is likely to remain subdued over peninsular
India for about a week. This slowdown is most pronounced in southern India, which is experiencing a significant rainfall deficit. However, this is not a formal withdrawal. The monsoon trough, an elongated low-pressure area that drives rainfall, is still active and extending from northwest India towards the Bay of Bengal, maintaining wet conditions over parts of north and central India. As of early September, the nationwide rainfall deficit stands at around 14%, with the south peninsula and east and northeast India facing the most significant shortfalls of 27% and 24% respectively.
An Uneven and Erratic Season
This year's monsoon has been marked by its erratic nature, characterised by prolonged dry spells followed by short, intense bursts of rain. This uneven distribution means that even as some regions grapple with deficits, others have faced floods and landslides. For instance, while states like Andhra Pradesh and Telangana are facing deficits of over 20%, Odisha has recorded excess rainfall. This variability has significant consequences for agriculture. September's rainfall is crucial for summer-sown crops that are at a critical growth stage and for ensuring adequate soil moisture for the upcoming winter cropping season. A prolonged dry spell now could negatively impact crop yields across the country's rain-fed agricultural belts.
The Bay of Bengal: A Beacon of Hope
Meteorologists are closely watching the Bay of Bengal for signs of a monsoon revival. According to the IMD, a fresh cyclonic circulation is expected to form over the central and adjoining northwest Bay of Bengal in the coming days. This system is likely to develop into a low-pressure area, which has the potential to increase rainfall over eastern and adjoining parts of peninsular India in the second week of September. These systems are the primary drivers of monsoon rain. They typically form over the bay and move westwards across the country, bringing widespread showers. The development and track of this new system will be critical in determining whether the current lull will be broken.
What is the Madden-Julian Oscillation?
Another major factor influencing the monsoon is the Madden-Julian Oscillation (MJO). The MJO is a large, eastward-moving pulse of clouds, rainfall, and wind that travels around the equator, typically every 30 to 60 days. When the MJO is in its active (or wet) phase over the Indian Ocean, it can enhance monsoon rains. Conversely, when it is in its suppressed (or dry) phase, it can lead to a break in the monsoon. Forecasters monitor the MJO's position and strength to predict rainfall patterns weeks in advance. An active MJO passing over the Indian Ocean in the coming weeks could provide the necessary trigger to reinvigorate the monsoon, working in tandem with the low-pressure system forming in the Bay of Bengal.
What the Forecast Says
While peninsular India waits for relief, the IMD predicts fairly widespread rain over several central and eastern states. Chhattisgarh, Odisha, and Vidarbha are expected to receive significant rainfall between September 8 and September 12. For regions like Rajasthan, a revival is anticipated around September 12. This indicates that the monsoon is far from over, but its activity will be patchy and regional rather than a uniform, nationwide revival. The withdrawal process, which normally begins from northwest India in early September, has become increasingly erratic in recent years and is not expected to be a swift process this year either.
