How do these weather events usually affect the winter weather?
A. Because even the most dedicated scientists do not thoroughly understand El Niño and La Niña (we do not know, for instance, why the trade winds suddenly die down and allow the warm water pool to move eastward), we can only describe certain tendencies in the weather. In the past, El Niño has often brought heavy rains to southern California and to a portion of the South from Atlanta to Cape Hatteras; it can bring relatively mild winter temperatures to the northern third of the country. However, these effects are not consistent in every El Niño event on record. The stronger the La Niña, the more severe the droughts. The La Niña in 2009 is creating severe drought in much of the world, causing an agricultural crisis.
