Hello La Nina: Will weather phenomenon bring rain and snow to Northern Nevada?
A weak La Nina has arrived and may stick around through winter, NOAA announced Thursday. Forecasters say the climate phenomena will likely contribute to drier and warmer weather in the southern U.S. and wetter, cooler conditions in the Pacific Northwest and across to the northern tier of the nation this winter.
NOAA scientists declared the arrival of La Nina on Thursday, calling it present, but weak. It is predicted to be short-lived, possibly only lasting a few months. La Nina is associated with cooler-than-average sea surface temperatures in the Equatorial Pacific, which trigger changes in the atmosphere.
Last month, NOAA scientists announced its upcoming winter outlook, which doesn't fare well in drought-stricken Nevada and California. Forecasters say the drought will likely persist through the winter in many regions currently experiencing drought, including the southwest. See the map above.
With the La Nina, however, it does appear heavier precipitation from Pacific Northwest northwest storms may have a better chance of moving south into the Sierra, forecasters say.
This ocean-atmosphere coupling impacts the position of the Pacific jet stream influencing weather and climate patterns around the globe.
“A weak La Nina is in place and is likely to remain for the winter,” said Mike Halpert, deputy director, NOAA’s Climate Prediction Center. "The weak La Nina is likely to contribute to persisting or developing drought across much of the southern U.S. this winter."
This La Nina follows one of the strongest El Ninos on record, which ended in June. Recent La Nina years include 2011-2012; 2010-2011; 2007-2008; and 2000-2001. Find out more about La Nina on the ENSO Blog.