Story highlights La Niña is characterized by a cooling of ocean waters in the Pacific

The climate pattern is likely to worsen drought in the southeastern US

(CNN) The long awaited La Niña, which was first predicted by the Climate Prediction Center (CPC) back in April, has finally arrived in the Pacific Ocean, NOAA announced Thursday -- and it's expected to stick around through the winter.

La Niña conditions, which are characterized by below-normal sea surface temperatures in the tropical Pacific, were observed during October and have persisted into November -- prompting the CPC to raise the ENSO Alert System from a La Niña Watch to a La Niña Advisory.

La Niña, much like its warmer counterpart, El Niño , have far reaching global impacts extending beyond the Pacific Ocean.

Photos: What are the different impacts of La Niña and El Niño? Hide Caption 1 of 4 Photos: What are the different impacts of La Niña and El Niño? Hide Caption 2 of 4 Photos: What are the different impacts of La Niña and El Niño? Hide Caption 3 of 4 Photos: What are the different impacts of La Niña and El Niño? Hide Caption 4 of 4

For the United States, NOAA forecasters say the current La Niña will "likely contribute to drier and warmer weather in the southern US and wetter, cooler conditions in the Pacific Northwest and across to the northern tier of the nation this winter."

This is bad news for the southeast, which is currently seeing an expanding and worsening drought. Following an autumn that had well above-average temperatures and scant rainfall has left more than 20% of the region in an Extreme or Exceptional Drought, the two highest designations in the US Drought Monitor.

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