You may have already heard on the nightly news that the scientific community is concerned about El Nino conditions this year, but many do not even know what El Nino really is. Many weather terms are tossed around on a regular basis with little understanding of what the occurrence really is. This article is designed to help you understand El Nino and find out what preparations need to be done if any.
An El Nino is the warming of the surface waters in the centrally located Pacific Ocean. While the warming of waters may not seem to be that drastic it creates the possibility of drastic weather systems across the globe.
North-easterly winds push warmer waters westwards through the Pacific Ocean onto Indonesia, letting cool water rise to the surface further east off the coast toward Mexico and South America.
As these north-easterly winds weaken an El Nino will begin to develop, this allows warm water over the west Pacific to move eastward into the Americas.
If trade winds were to strengthen a La Nina would develop and the waters would become much cooler.
An El Nino’s effects are rather easy to track and predict around the Pacific Ocean. During these periods of instability, South American and the south-west United States will see much higher amounts of rainfall. For areas such as California who have been involved in a drought for several years that is welcome news.
With warmer waters though comes the risk of more hurricanes. Two hurricanes have already developed off the west coast of Mexico and more can be expected. During this time period hurricanes in the Atlantic area tend to become lower.
In other parts of the world, it has yet to be determined what exactly are the affects of El Nino if any. It may depend on the time of year and how much the water warms. In fact, in Europe and the UK it has been impossible to determine any significant changes at all.
When there is a particularly strong El Nino, there is an increase in high pressure across Europe that leads to warmer and drier weather. El Nino is only beginning to develop and is unlikely to be particularly strong, it is not expected to have much impact on European weather.
One of the last strong El Ninos occurred in 1997/98 when the centrally east Pacific water temperature rose an incredible 4C. That ended up being one of the warmest global years on record. There have been no major El Ninos which may be one of the reasons we have seen very little global temperature change in the last 15 years. You can learn more about this weaher effect from this video presentation by the UK Met Office.