Kerala: As the country faces its April heat wave, with temperatures peaking at 44 °C in several places, new climate models seem to bring good news. Recent models forecast a likely advanced onset of the southwest monsoon, which may arrive on the coast as early as late May.
Whereas the nation’s capital region and central areas are struggling with extreme heat conditions, new forecasts indicate favorable atmospheric factors linked to advanced season transition.
Andaman gateway: Initial signs of approach
Monsoon onset usually starts at the Andaman and Nicobar Islands, and this year seems no different, with early indications of the coming season’s onset.
Forecast period: The sub-seasonal forecast indicates a 6-day window within which the monsoon will move towards the area; that is, it will hit the area between May 18 and May 25.
Weather indicators: Favorable atmospheric winds have started forming over the southern Bay of Bengal. According to forecasters, there might be 30-60 mm more rainfall than average over the islands during the forecast period.
Tropical systems: Climate experts report a possibility of developing a tropical system at the area with a probability of about 20-40%. This system would work as a “booster” attracting additional moisture towards the region.
Kerala prepares for early monsoon
By the last week of May (May 25 to June 1), there is an expectation that the onset of monsoon activity will push ahead to southwest coastal India.
The setting up of strong westerlies in the southeast Arabian Sea could push high levels of humidity into the areas of Kerala and southern Tamil Nadu. This, if it happens, could allow the onset in Kerala, which normally occurs around June 1, to come much earlier on May 25.
Drivers of the early onset: Role of IOD & high temperatures
The early onset of monsoon activity is due to the presence of favorable conditions in the Indian Ocean, as well as high temperatures inland at this time.
Indian Ocean dipole: According to experts, an ideal IOD (warmer western Indian Ocean) would mean enhanced monsoon activity.
El Nino Status: More importantly, El Niño, which has been an impediment to monsoons in past years, will remain neutral this time around.
Land pressure: Current high land temperatures in the north and central parts of India have created a low-pressure region that, like a vacuum, could attract the moisture-laden winds in advance.
Bureau Report
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