New System Created to Warn of El Nino Conditions
Will Alert of Conditions Up to Three Months in Advance
Feb 8, 2009
The new system will alert the general public to upcoming events, or keep them abreast of current El Nino or La Nina conditions. Like alerts for winter storms, a possible upcoming event is warned by a "watch," while a current event would have an "advisory" issued for it.
El Nino conditions signify an area of warmer than normal ocean water temperatures in the Equatorial Pacific, while La Nina conditions are the opposite (colder). Both events can affect weather conditions around the globe significantly when compared to averages.
NOAA is calling the service the ENSO Alert System. ENSO stands for El Nino Southern Oscillation, the scientific name for these events.
How the ENSO Alert System Works
The Climate Prediction Center (CPC) will issue two types of alerts for these events. When it feels that conditions are favorable for the development of a La Nina or El Nino event within three months, it will issue a watch. However, if an event is occurring, that watch would be upgraded to an advisory.
NOAA says the alerts would become a regular feature of its monthly status updates on the ENSO, which are issued on the Thursday falling between the 5th and 11th of each month. The agency makes these available online.
El Nino Events Affect Many
NOAA officials say that the system is needed because of the wide-ranging consquences that the climatic changes these events bring can affect a wide range of activities and industries, including agriculture, transportation, energy, shipping and construction.
"The ENSO Alert System will succinctly inform industry, government agencies, academia and the public about the onset and status of La Niña and El Niño," CPC deputy director Michael Halpert said. "This system will also help decision makers plan for the potential effects presented by these conditions.”
Typical Weather Effects of La Nina and El NIno Worldwide
While every ENSO event is different, generally there are similarities between the events in terms of overall weather conditions.
El Nino events commonly are associated with warmer winters across the North American continent, with frequent winter storms across the southern United States. Warmer conditions also occur across the Far East. Across the Southern Hemisphere, drought is rather prevalent, especially in the Western Pacific and Australia. There is one exception to this, and that is along the Northwestern coast of South America.
La Nina events are different. Heavy monsoons occur across Southeast Asia, while cooler conditions exist across southeastern Africa, western Canada, and the northwest USA. Wetter than normal conditions also occur across Southeast Africa as well as the northeast USA. Extremely wet conditions persist across southwestern Canada, while drought strikes the southeast USA.
Source: Pidwirny, M. (2006). "El Nino, La Nina and the Southern Oscillation". Fundamentals of Physical Geography, 2nd Edition.
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