National Oceanic and Atmospheric Administration (NOAA) of USA taking into account the developing scenario in the atmosphere and ocean over Pacific region and the output of predictions from Dynamical and Statistical models have forecast a weak El Nino to begin in September, and last till February 2013. Generally El Ninos begin in May-June, reach maximum phase in December-January and die in March-April of the following year, Joseph said.
So far the expected El Nino has not set in, we are still in El Nino neutral state. But scientists are expecting the El Nino conditions to begin in a month or two, he added.
India was passing through a La Nina condition during the monsoon of 2011.The La Nina is a cooling of the tropical Pacific Ocean and the last one had brought drought like conditions in Argentina and Brazil and flooded plantations in Thailand and Malaysia. The monsoon of 2011 was exceptional with 92% of India receiving normal or excess rainfall.
The current monsoon, which began in the neutral phase after La Nina, has recouped the initial deficit and is currently only 5% below normal. In June and July rainfall was well below normal and all India rainfall deficiency reached minus 22%. The situation progressively improved from the beginning of August.
India was in the El Nino phase during the monsoon of 2009 and the shortfall from normal was almost 22 %.