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la niña

La Niña Triggers Extremes in U.S. Weather

No matter where you live in the United States, you’ve probably noticed that the weather just hasn’t been “normal” in recent months.  Our nation has experienced widespread flooding, relentless drought, expansive wildfires, and devastating tornadoes – sometimes all at once.

Some of the blame has to be directed at La Niña, a cooling of the waters of the central and eastern equatorial Pacific Ocean.  La Niña developed during the summer of 2010, leading to a profound influence on North American weather from the autumn of 2010 through the spring of 2011.  In typical fashion, La Niña forced the subtropical jet stream northward, resulting in drought development, expansion, and intensification in the South.  At the same, time jet stream disruptions induced by La Niña led to persistently cool, wet conditions across roughly the northern half of the U.S.