Could El Ni帽o end California's drought?
The weather phenomenon known as El Ni帽o is coming, raising the prospect of heavy rains that could relieve California鈥檚 record three-year dry spell. 聽
In a statement issued earlier this week, the National Oceanic and Atmospheric Administration聽聽there is a greater than 90 percent chance that El Ni帽o will continue through the winter of 2015-16, and around an 80 percent chance it will last into early spring 2016.
El Nino - Spanish for 'the boy' - forms every two to seven years and warning signs emerge months in advance. 海角大神's Pete Spotts explains:
El Ni帽o occurs when easterly trade winds in the tropical Pacific relax 鈥� even reverse 鈥� to allow a vast pool of warm water piled up in the western tropical Pacific to move east until it reaches the west coast of Central and South America, leading to higher-than-normal sea-surface temperatures across the equatorial Pacific.
As the ocean releases its heat and moisture to the atmosphere, intense thunderstorms once cooped up over the western Pacific spread along the equator as well. The cumulative effect of this activity changes large-scale circulation patterns at higher latitudes, altering storm tracks that change the typical distribution of rain and snowfall, as well seasonal temperatures.
California has been experiencing its worst drought on record and the expected wet season could offer much needed rain.聽鈥淭he stronger this event becomes, the more confident that next winter we鈥檒l see stronger precipitation in California and the whole southwestern United States,鈥� said Mike Halpert, an official at NOAA聽
Last year forecasters had predicted a major El Ni帽o聽event but it failed to materialize plunging California into extreme drought.
However, experts say the long awaited heavy rains will have to stay strong until winter to bust the state鈥檚 drought. 聽鈥淭he key is really whether this event maintains its strength into the winter,鈥� Daniel Swain, an atmospheric science Ph.D. student at Stanford University 鈥淲hile the models do think that will likely happen, we still don't know for sure.鈥�
In previous strong El Ni帽o events, California has seen a 150 percent聽to 200 percent increase in rainfall, according to Mr. Halpert at NOAA.
The El Ni帽o 2015, whose expected start time is between July and November, is the first time such weather shift in five years.
It鈥檚 still too early for California to sigh with relief. 鈥淲ith weather there is no guarantee. El Ni帽o is only one of many things that could impact California鈥檚 rainy season,鈥� Tom Di Liberto, meteorologist for the federal Climate prediction center,
El Ni帽o聽can have devastating effects as often results in heavy rains, floods, and landslides. The last strong El Ni帽o happened in 1997-1998 and to have caused losses of between $10 billion and $25 billion in the U.S.
