El Nino conditions return to affect U.S. weather

U.S. government scientists say El Niño, the periodic warming of water in the tropical Pacific Ocean that can influence weather around the world, has returned.

The Pacific had been in what is called a neutral state, but forecasters at the National Oceanic and Atmospheric Administration say the sea surface temperature climbed by 1.8 degrees Fahrenheit along a narrow band in the eastern equatorial Pacific in June.

One of El Niño's positive effects is to help to suppress Atlantic hurricane activity. In the USA, it typically brings beneficial winter precipitation to the arid Southwest, less wintry weather across the North, and a reduced risk of Florida wildfires. El Niño's negative impacts include damaging winter storms in California and increased storminess across the southern USA.

Elsewhere, El Nino conditions are associated with increased rainfall across the east-central and eastern Pacific and with drier than normal conditions over northern Australia, Indonesia and the Philippines.

The administration's Climate Prediction Center also reported today that temperatures in other tropical regions are also above normal, including readings as much as 975 feet below the surface of the ocean.