5 September 2023

September 2023 Unlikely to Perform Monsoon Miracles As IMD Predicts Normal Rains and Warmer Days Across India


Friday, September 1: August 2023 has etched its name in the record books as India's driest August since recordkeeping commenced. The long monsoon ‘break’ saw the countrywide deficit reach 11% after the first three months of the season, thereby surpassing the dreaded drought threshold of over a 10% shortfall. The nation's collective gaze now turns to September, although early signs do not promise a miraculous comeback.

The India Meteorological Department’s (IMD) latest predictions for September 2023 point towards normal rainfall for India. This translates to actual rainfall levels falling within 91-109% of the country's long-period average (LPA) for the month. According to historical data spanning 1971-2020, the September LPA stands at 167.9 mm.

Through the month, above-normal rainfall is most likely over many areas of Northeast India, adjoining East India, the foothills of the Himalayas and some areas of East-Central and South Peninsular India. Most areas in the remaining parts of the country will be in for normal to below-normal precipitation.


Probability forecast of maximum and minimum temperatures during September 2023.(India Meteorological Department)

On the mercury front, the majority of the country is poised to endure hotter-than-normal days. A few lucky exceptions, mainly some pockets in South Peninsular India and West-Central India, may experience normal to below-normal daytime temperatures.

Nighttime will also bring above-average minimum temperatures for most regions, barring some areas in extreme north India, where normal to below-normal minimums are projected.

Meanwhile, weak El Niño conditions currently loom over the equatorial Pacific region. This unusual warming in the Pacific tends to induce drier conditions across the Indian subcontinent — a phenomenon experienced vividly throughout August. In fact, the latest forecasts from MMCFS and other global models suggest that El Niño is poised to strengthen further and continue up to the early months of 2024.

Another determinant of the Indian monsoon's trajectory is the Indian Ocean Sea Surface Temperatures. Presently, the Indian Ocean hovers on the cusp of borderline positive Indian Ocean Dipole (IOD). However, positive IOD conditions are expected to intensify in the coming months, although their timing may be too late to significantly impact precipitation activity across the Indian subcontinent.

O​verall, the accuracy of this month-long forecast looms as an intriguing question, given the notable disparities in IMD's predictions for August. The forecast had hinted at a minor rain deficiency ranging from 6% to 10%, whereas the actual countrywide deficit ended up soaring past the 30% mark.

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