As we move further closer to the Southwest Monsoon 2017, speculations about its performance have also started doing rounds. Monsoon rains hold prime importance in India, as around 60% of its population is engaged in agricultural activities.
Skymet Weather has predicted that the upcoming Southwest Monsoon 2017 is likely to be below normal at 95% (with an error margin of +/-5%) of the long period average (LPA) of 887 mm for the four-month period from June to September.
The culprit to be blamed is the notorious El Niño, whose effect will be visible July onwards. Most of the weather models are indicating towards 60% chance of El Niño coming into existence during the second half of the Monsoon. As reiterated earlier, evolving El Niño is equally harmful for the performance of Monsoon.
According to Jatin Singh, CEO, Skymet Weather, Rising sea surface temperatures are already reflecting that El Niño is in the evolving stage. There is 25% chance of below normal rains and 15% chance of drought.
El Niño is invariably linked with the poor Monsoon rains in the country. As per the latest reports, El Niño Southern Oscillation (ENSO) neutral conditions have started developing. The Pacific Ocean has already started heating up and the Niño index has reached the positive value of 0.3 on March 20, 2017.
According to Skymet Weather, these neutral conditions may continue till the onset of Monsoon. Thereafter, we expect El Niño to develop during the latter part of August or September, which can have adverse effect on the performance of the Monsoon.
However, presence of positive Indian Ocean Dipole (IOD) and heating of land mass of Central India would also influence the Monsoon rains. But whether they would be able to withstand El Niño is the question.
The positive IOD is linked with good Monsoon rains, while the negative IOD has an adverse effect on the same.
Besides this, whenever there is intense heating of Indian land mass, a heat low develops over central parts of the country that pulls the Monsoon current towards Indian land mass. Weathermen are already predicting extremely hot summers this season on account of lesser number of pre-Monsoon activities.
Both the factors are beneficial for the good Monsoon rains. Although both the factors are prevailing this season, however, historically it is seen that whenever there has been El Niño or La Niña condition, IOD has become insignificant.
There has been only one incidence in the history when despite the presence of strong El Niño, Monsoon rains in 1997 were above normal on account of a positive IOD.
Courtesy: skymetweather.com