'Above-normal' monsoon: Here's the basis for IMD's positive forecast for rains

After droughts and heat waves across various regions, India has finally got some much-needed good news. The Indian Meteorological Department (IMD) in a statement on Tuesday said that the country will receive “above normal” monsoon with a fair distribution of rainfall across major parts of country. [caption id=“attachment_2726980” align=“alignleft” width=“380”] A weakening El Nino is one of the reasons behind the IMD forecast for an ‘above normal’ monsoon. AFP[/caption] IMD Director General Laxman Singh Rathore said there are 94 percent chances of country receiving “normal to above normal” rainfall while there is only one percent probability of “deficient” rainfall. The monsoon seasonal rainfall will be 106 percent of the Long Period Average (LPA) with a model error of plus or minus 5 percent. “Above normal” monsoon is between 104-110 percent of the LPA and anything beyond 110 percent of the LPA is considered as “excess”. This positive forecast by the IMD is based on the following reasons: Weakening of El Nino El Nino is a phenomenon associated with the warming of waters of the central and east-central equatorial Pacific. This phenomenon has been linked with weakening of the monsoon rains and droughts in India. Moreover, the El Ninos in 2014 and 2015 — considered to be among the strongest El Nino years — were held responsible for the successive drought years, according to The Hindu. But the El Nino is going to weaken this year, according to IMD. “The latest forecast from the Monsoon Mission Coupled Climate Model indicates that El Nino conditions to weaken to moderate to weak levels during the first half of the monsoon season and ENSO neutral conditions likely to get established thereafter (sic),” said the IMD statement. Indian Ocean Dipole This phenomenon causes the western Indian ocean to become warmer and then colder than the eastern part of the ocean, which pushed rain-bearing clouds over India. The IMD statement said that “positive” conditions for this phenomenon were likely to be established during the middle of the monsoon season, according to forecast from the Monsoon Mission Coupled Climate Model. La Nina The La Nina, also known as the anti-El Nino, causes the cooling of waters in the equatorial Pacific. The report in The Hindu added that La Nina was expected to set in around September and is considered to be good for rainfall. The IMD statement added that it is “carefully monitoring the sea surface conditions over the Pacific and the Indian oceans”. You can read the full IMD statement here:

(With inputs from PTI)