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Most Climate Model Show Return of El Nino
Apr 17, 2014

According to UN World Meteorological Organization, majority of weather forecasting models indicate that an El Nino weather phenomenon may develop around the middle of the year, but it is too early to assess its likely strength. Model forecasts indicate a fairly large potential for an El Nino, most likely by the end of the second quarter of 2014.

The WMO statement follows predictions by several national forecasters, including the US, Japanese and Australian weather bureaus that an El Nino event was likely within months. For the June to August period, approximately two-thirds of the models surveyed predict that El Nino thresholds will be reached, while the remaining models predict a continuation of neutral conditions. A few models predict an earlier El Nino onset, such as in May.

Many foreign forecasters say the probability of El Nino developing this year is 75%, while the US based National Oceanic and Atmospheric Administration's Climate Prediction Center says there is a 50% chance of El Nino developing during the summer.

According to the United States Department of Agriculture (USDA), if El Nino were to become established, impact on India would be most prevalent in the 2015 summer monsoon. This position on El Nino is likely to change in the next couple of months. Since the exact timing of the developing El Nino in the Pacific is still uncertain, as it relates to the summer monsoon season (June-September) in India, its possible effects on the total monsoon rainfall is hard to tell with any certainty at this time.

The climate forecast system global model will in the coming weeks give an indication of the possible impact of the developing El Nino on the Indian monsoon this year, The percentage of probability of El Nino will probably increase based on continued developments in the tropical equatorial Pacific. India's Meteorological Department has not yet issued its monsoon forecast. Meteorologists say in the past, El Nino has often, but not always, disrupted the flow of normal monsoon clouds in the June-September rainy season.

El Nino is a shift in ocean temperatures and atmospheric conditions in the tropical Pacific that disrupts weather around the world. EL Nino refers to the warm current that flows southward along the coasts of Ecuador and Peru, between January and March. This anomaly, which occurs every 2 to 7 years, causes variability of the monsoons. When pressure is high over the Pacific Ocean, it tends to be low over the Indian Ocean from Australia to Africa. As pressures are inversely related to rainfall, it implies that low pressure over the Indian Ocean would result in a good monsoon.

During El Nino year the warm water replaces cold currents in Eastern Pacific (Chile, Peru coasts). This creates a low pressure zone in that region and a relatively high pressure conditions in the Indian Ocean region. This high pressure conditions in the Indian Ocean can be detrimental to the monsoons.


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