Summer Outlook: Possible El Nino?

Image from SFSU

         After finally getting through a very stubborn winter, we now look forward to the warmer and drier summer season. Currently on every atmospheric scientists and meteorologists’ radar is the impending El Nino event–one of our planet’s most prevalent weather phenomena. El Nino is an intricate weather pattern that results from variations, or sometimes called oscillations, in ocean surface temperatures along the equatorial Pacific Ocean. Scientists declare an El Nino event when the Pacific Ocean water surface temperature, off the coast of Peru and Ecuador, becomes higher than 0.5 degree for three consecutive months. This warmer water cycle stretches 5,000 miles from South America, moving westward towards Australia and Indonesia. As this belt of water sweeps across the Pacific Ocean, trade winds weaken and even reverse course, creating a low-pressure system over areas, such as Peru and Ecuador, and a high-pressure system over Australia and Indonesia. A mild El Nino event is present when the ocean surface is warmed by 1 to 2 degrees Celsius, and stronger El Nino events occur when the water is warmer by 3 to 4 degrees Celsius. An El Nino event can last as long as several months up to an entire year.  Currently, temperatures in the eastern and central Pacific Ocean are the warmest on record for March since 1979. Australian meteorologists currently report water temperatures up to 7 degrees above the average. Another impending sign of an extreme weather event is the reversal of the Pacific trade winds. Therefore, this years’ El Nino event could compete as one of the most intensive on record. These El Nino events normally appear in the late winter season, but since this event currently appears to be very strong, scientists are expecting El Nino to make an earlier appearance, possibly this summer. 

       El Nino brings considerable global weather consequences. For the U.S. El Nino brings more storms to the California coast and wetter weather conditions in the southern states. The Pacific Northwest experiences warmer conditions, and a decrease in the threat from hurricanes on the Atlantic coast and Gulf of Mexico. We can also expect more storms to adversely impact the Californian coast. The west coast storms will finally bring rain to drought-ridden California. Also, due to a recent oil spill in the Gulf of Mexico, a quieter hurricane season is much needed so the spilled oil stays contained in a localized area and not wash up onto a wide span of coastline. We can also presume the continuation of a severe drought in Indonesia and India, more bush fires in Australia, drier conditions in Central America, and warmer global temperatures due to the heat released into the atmosphere from the tropical Pacific Ocean. So while North America receives wetter weather, Asia and Oceania receive drier weather.  The stronger the magnitude of an El Nino, the more drastic the consequences will be for the planet. 

Currently, the director of NOAA’s Climate Prediction Center reports that there is a greater than 50% chance of El Nino developing as early as summer and a 75% likelihood of it developing in fall. An El Nino watch has been issued to warn of the potential severe conditions that can occur around the world. Although spring El Nino predictions have proven to be incorrect in the past, all signs point that this El Nino event may be one of record proportions!

A question researchers are going to have to explore in years to come, is if climate change is increasing the frequency of El Nino events.

To extend your knowledge about El Nino, check out NOAA’s link.