The condition, following two years of strong, cool-water La Nina events, make long-range climate forecasting more difficult due to its greater unpredictability, NASA's Jet Propulsion Laboratory in Pasadena, Calif., said Wednesday.
"This past spring, after two years of La Nina, the expected El Nino was a no-show," JPL climatologist Bill Patzert said. "La Nina faded and 'La Nada' conditions locked in.
"This absence of El Nino and La Nina, termed 'neutral' by some, has left long-range climate forecasters adrift," he said. "Seasonal, long-range forecasting works best when signals like El Nino and La Nina are strong."
Patzert said he prefers to use the term "La Nada" rather than "neutral," which implies to some that weather will be "normal."
"I never say the word 'normal' when it comes to winter weather in the American West," he said, noting La Nada periods have delivered both the wettest and driest winters on record in Los Angeles.
"For long-range forecasters, La Nada is a teeth-grinder."