The National Oceanic and Atmospheric Administration’s Climate Prediction Center now estimates a 71% chance of La Niña forming between October and early December, with a 54% chance of continuing from December to February.

The El Niño-Southern Oscillation (ENSO) stayed neutral through August, but most models now favor a La Niña pattern this winter. Current ocean data show ENSO-neutral conditions, with cooler-than-normal waters in the central and eastern Pacific and subsurface temperatures also below average.

Scientists expect La Niña to bring warmer southern U.S. winters and cooler northern conditions, along with a more active hurricane season. The South may face drought, while the Pacific Northwest and Canada could see heavy rain and flooding.