BackWho will get this year’s monsoon forecast right—IMD or Skymet?
IMD says monsoon rainfall this year would be 93% of the long-period average, while Skymet forecasts it to be 102%
Premium
New Delhi: The southwest monsoon has advanced over the Andaman and Nicobar Islands and looks set to cross the Indian mainland through the south Indian state of Kerala by the end of May, according to both government forecasting agency India Meteorological Department (IMD) and private forecaster Skymet Weather Services Pvt. Ltd.
But that is the only weather prediction that is common between the two forecasters.
According to IMD, the probability of normal monsoon is bleak, and rainfall this year would be 93% of the ‘long-period average’. The main reason for the subdued forecast is the fear of an onset of the El Nino weather phenomenon—the warming of the Pacific Ocean waters triggering atmospheric changes that is usually associated with below-normal monsoon in India.
Skymet, which came out with its forecast before IMD did, said that monsoon will most likely be normal this year and that El Nino will not have much impact. Skymet forecast that monsoon rainfall will be 102% (+/- 4%) of the long-period average which is normal for the season. The private agency added that there is a 36% probability of above-normal rainfall and 49% chance of normal rainfall. The IMD has forecast a 68% probability of below-normal rainfall.
Last year, both agencies had forecast below-normal monsoon rainfall and India did face a meteorological drought. Monsoon season is crucial in a country where at least half the farmlands are rain-fed and more than 70% of the annual rainfall is concentrated in this season. Almost a quarter of the country—including Uttarakhand, Himachal Pradesh, Punjab, Haryana, Delhi, Uttar Pradesh, Rajasthan, east Madhya Pradesh, Telangana and parts of Maharashtra—faced drought-like conditions last year.
The IMD Ensemble Statistical Forecasting system for April uses five predictors which include the El Nino, sea surface temperature (SST) conditions in the equatorial Pacific and Indian Oceans, Equatorial South Indian Ocean SST, East Asia Mean Sea Level Pressure and Northwest Europe Land Surface Air Temperature.
After the latest update from the US National Oceanic and Atmospheric Administration that there is now a 90% chance that the El Nino will persist through the Indian summer, forecasts from both the agencies remain unchanged. “While there is uncertainty regarding distribution, we know that below-normal rainfall is certain this monsoon. If the El Nino persists, which is also certain, then historically speaking, northwest and north India will be affected the most," said D.S. Pai, chief of Long Range Forecasting Division at IMD.
According to Jatin Singh, CEO, Skymet, “The El Nino is likely to continue into the summer months and taper down thereafter. It is not likely to have an adverse impact on monsoon performance." Skymet formed its numerical prediction models based on dynamic components such as atmospheric pressure, and static data such as geographic coordinates, altitude, proximity to water bodies and land use.
Unlock a world of Benefits! From insightful newsletters to real-time stock tracking, breaking news and a personalized newsfeed – it's all here, just a click away! Login Now!
