El Nino Coming To An End While La Nina Develops

Created by doina. Last modified on 2007-03-14 10:49:02
Topic: Weather

February 2007 saw El Niño conditions disappearing according to the National Weather Service Climate Prediction Center.

Above averagely warm SSTs (surface and subsurface temperature) associated with El Niño disappeared from the eastern equatorial Pacific during February. Accompanying this drop in SST anomalies, the equatorial upper-ocean heat content (average temperature departures in the upper 300 m of the ocean) decreased rapidly during December 2006-January 2007, as the upper ocean cooled and negative temperature anomalies developed. These trends in surface and subsurface ocean temperatures indicate that the warm (El Niño) episode has ended and that conditions are becoming favorable for La Niña to develop.

Climate Forecast models indicate a rapid transition to La Niña conditions during March-May 2007. This scenario is supported by the latest surface and subsurface oceanic conditions, and the persistence of stronger than-average low-level easterly winds over the central equatorial Pacific. La Niña can cause stronger easterly trade winds in the eastern equatorial Pacific, drier than average conditions in the eastern Pacific and western US, as well increased rainfall to the west (Indonesia and Australia). La Niña also contributes to fewer eastern Pacific hurricanes and more Atlantic hurricanes.

NOAA Climate Prediction Center

http://www.cpc.ncep.noaa.gov/index.html