Why experts are predicting a normal monsoon

There are other factors too. This year,temperatures have been above normal all across the country in March and April. Theoretically,that should bring good rains. According to Medha Khole,director of weather forecasting at IMD,Pune,the persistent high temperatures in March and April may translate into creation of more low-pressure areas during monsoon season,leading to good rains.

Khole adds,“During March and April,the eastern parts of the country get frequent thundershowers. However,that has not been the case this year. As a result,the eastern part of the country is experiencing above-normal temperatures. In northern parts too,absence of convective precipitation has added to the heat. In the central part,the northwesterly winds bringing hot and dry air are increasing temperature.”

However,scientists observe that even after increase in temperatures in the last decade,there is not always a significant rainy season as predicted. “In fact there were two drought years,2002 and 2004,in the last decade,” says an IMD scientist. A study by the Indian Institute of Tropical Meteorology has shown that in the last decade,seven years have shown a visibly negative trend in rainfall. “Of the five parameters that are considered for the forecast of the southwest monsoon,the Equatorial Pacific Warm Water Volume (El Nino) and North Atlantic Sea Surface Temperature are favourable this year. The NW Europe Land Surface Air Temperature factor is,however,not favourable as the snow cover was thick over Eurasia this January. The other two factors—Equatorial South Indian Ocean Sea Surface and East Asia Mean Sea Level Pressure Temperature—are neutral. It increases the possibility of normal rain,” says Pai.