QUOTE(Gettin2Old @ Nov 4 2007, 09:27 AM)

Allegedly there is a "La Nina" setting up in the pacific, what will that bring?
So, whats the difference between an "El Nino" & a "La Nina"? does either of them brig snow to the midwestern states?
it sure would be nice to be able to ride right after deer season.
http://www.elnino.noaa.gov/lanina_new_faq.htmlQUOTE
What is La Niņa?
La Niņa is defined as cooler than normal sea-surface temperatures in the central and eastern tropical Pacific ocean that impact global weather patterns. La Niņa conditions recur every few years and can persist for as long as two years.
What is the difference between La Niņa and El Niņo?
El Niņo and La Niņa are extreme phases of a naturally occurring climate cycle referred to as El Niņo/Southern Oscillation. Both terms refer to large-scale changes in sea-surface temperature across the eastern tropical Pacific. Usually, sea-surface readings off South America's west coast range from the 60s to 70s F, while they exceed 80 degrees F in the "warm pool" located in the central and western Pacific. This warm pool expands to cover the tropics during El Niņo, but during La Niņa, the easterly trade winds strengthen and cold upwelling along the equator and the West coast of South America intensifies. Sea-surface temperatures along the equator can fall as much as 7 degrees F below normal.
Why do El Niņo and La Niņa occur?
El Niņo and La Niņa result from interaction between the surface of the ocean and the atmosphere in the tropical Pacific. Changes in the ocean impact the atmosphere and climate patterns around the globe. In turn, changes in the atmosphere impact the ocean temperatures and currents. The system oscillates between warm (El Niņo) to neutral (or cold La Niņa) conditions with an on average every 3-4 years.
What causes La Niņa?*
Typically, a La Niņa is preceded by a buildup of cooler-than-normal subsurface waters in the tropical Pacific. Eastward-moving atmospheric and oceanic waves help bring the cold water to the surface through a complex series of events still being studied. In time, the easterly trade winds strengthen, cold upwelling off Peru and Ecuador intensifies, and sea-surface temperatures (SSTs) drop below normal. During the 1988- 89 La Niņa, SSTs fell to as much as 4 degrees C (7 degrees F) below normal. Both La Niņa and El Niņq tend to peak during the Northern Hemisphere winter.
What's the difference between La Niņa and El Niņo?*
Both terms refer to large-scale changes in sea-surface temperature across the central and eastern tropical Pacific. Usually, sea-surface readings off South America's west coast range from the 60s to 70s F, while they exceed 80 degrees F in the "warm pool" located in the central and western Pacific. This warm pool expands to cover the tropics during El Niņo but shrinks to the west during La Niņa. The El Niņo/Southern Oscillation (ENSO) is the coupled ocean-atmosphere process that includes both El Niņo and La Niņa.
What are the global impacts of La Niņa?
Both El Niņo and La Niņa impact global and U.S. climate patterns. In many locations, especially in the tropics, La Niņa (or cold episodes) produces the opposite climate variations from El Niņo. For instance, parts of Australia and Indonesia are prone to drought during El Niņo, but are typically wetter than normal during La Niņa.
What are the U.S. impacts of La Niņa?
La Niņa often features drier than normal conditions in the Southwest in late summer through the subsequent winter. Drier than normal conditions also typically occur in the Central Plains in the fall and in the Southeast in the winter. In contrast, the Pacific Northwest is more likely to be wetter than normal in the late fall and early winter with the presence of a well-established La Niņa. Additionally, on average La Niņa winters are warmer than normal in the Southeast and colder than normal in the Northwest.
A colder, wetter than normal winter for the Pacific Northwest would certain bode well for us here in Wisconsin, assuming the jet stream is right.