Will Weakening El Nino Give Way to La Nina?
Here’s a satellite image of La Nina conditions in late 2007, with the blue representing cooler water.
A record-setting El Niño has been affecting weather around the world for months. It's brought much-needed rain to California, for example, but also boosted hurricanes in the Pacific and amplified the effects of drought in Indonesia, fueling massive wildfires. And though the surface temperatures may have peaked this fall, the effects on the atmosphere may be most acutely felt in the spring. Here we look at a some of the dramatic effects of theEl Niño–Southern Oscillation
In Indonesia wildfires burned thousands of acres during the fall. El Nino conditions led to dry forests, which exacerbated the risk of fires spreading out of control. Pictured: Haze shrouded Indonesian cities for months.
NASA Earth Observatory
"During El Niño years, rain that is normally centered over Indonesia and the far western Pacific shifts eastward into the central Pacific; as a result, parts of Indonesia experience drought," reportsNASA's Earth Observatory
. The lack of rain worsened fires that Indonesia's government said were intentionally set by plantation companies to clear land for palm oil cultivation and, ironically, tree plantations.Indonesia Fires Choking People, Threatening Wildlife
NASA Earth Observatory
In early December, Chennai, a city in India, saw an El Nino-inspired deluge, receiving more rain in one day than any other since 1901. This was preceded by a month of monsoon rains in the Indian state of Tamil Nadu that were well above normal,according to NASA
Above, fresh snow sits on the San Gabriel Mountains in the Angeles National Forest at sunset. A series of powerful storms intensified by El Nino hit Southern California during the first week of the year.El Niño Makes A Late Appearance
Mike Eliason/ZUMA Press/Corbis
Above, a surfer takes advantage of the high surf during near the entrance of Santa Barbara harbor.
Richard Eaton/ Demotix/Corbis
Work crews in San Diego diverted a gas line near a large sink hole that developed near a sea wall after heavy rain runoff near the La Jolla Beach and Tennis Club at La Jolla Shores.
Unless you’ve been hibernating with Punxsutawney Phil this winter, chances are that you know about El Niño, a periodic warming in surface ocean temperatures across the central and east-central equatorial Pacific Ocean, which has been altering weather across the globe. The effects have ranged from wildfire-causing droughts in Indonesia to ocean storms off the coast of Chile, with waves massive enough to rush up onto land and flip an SUV.
An El Niño’s effect on weather can be complex, and in some cases didn’t behave as predicted. In drought-ravaged California, for example, meteorologists thought the ocean temperature phenomenon probably would bring above-average rain to the southern part of the state in January, with a lesser chance of precipitation in the north.
Instead, the opposite happened — southern California stayed pretty much bone dry with just three days of rainfall, while northern California got the coveted rain and snow in the mountains.
But in any case, it’s time to start bidding farewell to El Niño. The National Oceanic and Atmospheric Administration’s latest status report notes that while still strong, it’s on the wane, and by May or June, temperatures should be back to the norm.
In fact, NOAA says there’s a possibility that during the fall, we may actually see Pacific Ocean temperatures swing in the other direction, so that we get an La Niña — that is, an unusually cold east-central Equatorial Pacific.
La Niña tends to bring nearly opposite effects of El Niño to the United States. According to the Weather Channel, that could mean that the Pacific Northwest and Ohio Valley will be wetter than average, while the southern part of the United States will be drier. Temperature-wise, an area stretching from the Pacific Northwest to the northern Plains will be cooler than usual, while the South, the Ohio Valley an the mid-Atlantic states will see above-average temperatures.
While La Niña doesn’t occur as often as El Niño, it often lasts longer, persisting or occurring for two or more years.The most recent La Niña was a relatively weak event in 2011-12. Here’s a historical chart.