After leaving a powerful impact over the last two years, the prevailing El Nino seems to be dwindling now. The present El Nino began evolving in 2014 and reached its peak by Monsoon 2015. It has done its deeds – brought back to back droughts and made 2015 the hottest year on record. The present status is not giving a totally comfortable feeling as either side of Nino 3.4 is still warm.
The figure above shows the current status of the surface temperatures anomalies in degree Celsius since the end of February. Some of the indices are still showing a rise. The last fortnight and current scenario indicates a level of neutrality.
The El Nino situation will turn into neutral by middle of 2016. Rest of the year (after Monsoon) will have the oceanic-atmospheric atmosphere incline towards La Nina conditions. La Nina is exactly the opposite of El Nino. Less heating leads to colder sea waters off western South America coast, thus making it a high pressure zone which pushes the moist sea winds towards the Indian Ocean. Therefore, the chances of normal or excessive rainfall in the Indian sub-continent increases. At the cost of repetition, we would like to say that data available in March is not credible. April forecasts are more reliable.
Must Watch: NOAA explains El Nino and La Nina phenomena
Past records do suggest that generally a strong La Nina is followed by El Nino but considering the present state, let us not be very optimistic about prospects of a big La Nina. Looks like, even the best of the drop rate may just suffice to reach a neutral ENSO at the time of onset of Monsoon.
Image credit - NBC News