I have heard several folks say that all of this snow and ice is from El Nino, and try to convince me that “Global Warming” is still very real. While El Nino does affect weather to some degree, it is not as reliable a predictor as most of us think. There are simply far too many variables at play, and weather is a very cagey thing!
Stu Ostro, Senior Meteorologist at the Weather Channel has written some great articles about El Nino. The following excerpt is from “Oh no, it’s El Nino!” which he published on September 14, 2006:
WHAT EL NINO IS
-A climate phenomenon that influences weather patterns. It specifically refers to above-average sea surface temperatures (SSTs) in the central and eastern equatorial Pacific Ocean (such as those highlighted in the recent map above).
-The opposite of El Nino (below-average SSTs in that portion of the Pacific) is known as La Nina. When SSTs are near average, that is called the “neutral phase.”
-El Nino and La Nina are related to both SST changes and the natural ebb and flow of trade winds across the tropical Pacific. The associated fluctuation in atmospheric pressure is known as the Southern Oscillation. The whole oceanic/atmospheric process is known as ENSO (El Nino/Southern Oscillation).
WHAT EL NINO IS NOT
-A storm. A flood. A drought. A hurricane. A weather event or pattern. (At times when its influence is particularly strong, such as when a very active southern jet stream and storm track are present during winter, that is sometimes referred to as an “El Nino pattern,” El Nino being a descriptor of the related, predominant weather pattern. However El Nino itself is not a weather pattern per se.)
-Abnormal or bizarre. Both El Nino and La Nina are a natural part of our world, and have likely been so for many thousands of years.
-The sole cause of individual weather events or the sole influence upon seasonal weather patterns. (The water/land/atmosphere/sun climate “system” is very complex.)
-Something that necessarily increases the amount of weather and climate calamities. There are certain locations that do typically experience specific kinds of impacts such as drought or flooding, but plenty of extremes and disasters of all kinds occur around the world when El Nino is not present. El Nino just tends to shift them around.
WHAT EL NINO DOES
-El Nino has a direct effect upon the atmosphere over the tropical Pacific.
-It has an indirect influence upon weather patterns in other parts of the world, including in and near the United States. The strongest influence in North America is during the “cold season,” i.e. from late autumn through winter and into early spring.
-The degree of this influence at any given time and place depends in part on El Nino’s intensity, which can vary, and on other weather and climate factors.