La Niña, which contributed to extreme weather around the globe during the first half of 2011 (including record snowfall), has re-emerged in the tropical Pacific Ocean and is forecast to gradually strengthen and continue into winter.
Today, forecasters with NOAA’s Climate Prediction Center upgraded last month’s La Niña Watch to a La Niña Advisory.
La Niña winters often see drier than normal conditions across the southern tier of the United States and wetter than normal conditions in the Pacific Northwest and Ohio Valley.
NOAA included a photo of a dry lake bed with their article. But because La Niña often brings colder, wetter winters to the Pacific Northwest and the northern Plains (remember the record snowfall last winter?), I’m using a picture of snow. (Remember the record floods on the Missouri River this spring and summer?)
“This means drought is likely to continue in the drought-stricken states of Texas, Oklahoma and New Mexico,” said Mike Halpert, deputy director of the Climate Prediction Center. “La Niña also often brings colder winters to the Pacific Northwest and the northern Plains, and warmer temperatures to the southern states.”
The strong 2010-11 La Niña contributed to record winter snowfall, spring flooding and drought across the United States, as well as other extreme weather events throughout the world, such as heavy rain in Australia and an extremely dry equatorial eastern Africa.
La Niña conditions returned in August 2011 due to the strengthening of negative sea surface temperature (SST) anomalies across the eastern half of the equatorial Pacific Ocean.
La Niña is a naturally occurring climate phenomenon located over the tropical Pacific Ocean and results from interactions between the ocean surface and the atmosphere. During La Niña, cooler-than-average Pacific Ocean temperatures influence global weather patterns. La Niña typically occurs every three-to-five years, and back-to-back episodes occur about 50 percent of the time.
Across the contiguous United States, temperature and precipitation impacts associated with La Niña are expected to remain weak during the remainder of the Northern Hemisphere summer and early fall, and to generally strengthen during the late fall and winter.
See entire article:
Thanks to Chuck Clancy and Thomas McHart for these links