Rain making system arrives with El Niño, but is there a connection?

AUSTIN (KXAN/NOAA) — The Climate Prediction Center announced last week the formation of El Niño conditions in the equatorial Pacific Ocean. While today’s rain making storm system over Texas originated in the Pacific, a direct link to the ocean phenomenon is uncertain. But, because of the pattern, the Climate Prediction Center is forecasting a wetter than normal spring for Central Texas.

El Nino pattern developsAn El Niño develops when unusually warm ocean temperatures begin to influence weather patterns. That connection last developed in Central Texas during the winter of 2009-2010. Since that time, historic drought conditions developed across Texas as two consecutive La Niña cycles (opposite of El Niño) formed.

The El Niño cycle typically brings Texas wetter and colder than normal winters, but the impacts tend to wane during the spring and summer. While not all El Niño months are big rain-makers for Central Texas, some have resulted in record rainfall and flooding, filling area lakes.

The term El Niño refers to the large-scale ocean-atmosphere climate phenomenon linked to a periodic warming in sea-surface temperatures across the central and east-central equatorial Pacific (between approximately the date line and 120oW). El Niño represents the warm phase of the El Niño/Southern Oscillation (ENSO) cycle, and is sometimes referred to as a Pacific warm episode.

 

The term El Niño (Spanish for “the Christ Child”) was originally used by fishermen along the coasts of Ecuador and Peru to refer to a warm ocean current that typically appears around Christmastime and lasts for several months. Fish are less abundant during these warm intervals, so fishermen often take a break to repair their equipment and spend time with their families. In some years, however, the water is especially warm and the break in the fishing season persists into May or even June. Over the years, the term “El Niño” has come to be reserved for these exceptionally strong warm intervals that not only disrupt the normal lives of the fishermen, but also bring heavy rains.

NOAA’s Climate Prediction Center, which is part of the National Weather Service, declares the onset of an El Niño episode when the 3-month average sea-surface temperature departure exceeds 0.5oC in the east-central equatorial Pacific [between 5oN-5oS and 170oW-120oW].

  • La Niña or El Niño Watch: conditions in the equatorial Pacific are favorable for the development of La Niña or El Niño conditions in the next three months.
  • La Niña or El Niño Advisory:  La Niña or El Niño conditions have developed and are expected to continue.

These watches and advisories are now part of the ENSO Diagnostic Discussion, which is issued by the Climate Prediction Center on the Thursday falling between the 5th and 11th of every month. It is available online.

Click here to visit the Climate Prediction Center’s ENSO site.

NOAA understands and predicts changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.

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