The National Weather Service's Climate Prediction Center (CPC) says La Nina strengthened in October and a majority of weather models suggest it will continue through the winter, but then gradually weaken after peaking in the November to January period.
CPC says the models are roughly split between those that predict La Nina to remain weak and those that predict a stronger episode. "Over the last half-century, La Nina events that were preceded by ENSO-neutral conditions during the Northern Hemisphere summer (May-August) were less likely to attain strong amplitude (less than -1.5oC) the following winter," it states. "This observation, in combination with the model forecasts, favors a weak-to-moderate strength La Nina during the Northern Hemisphere winter."
As a result of La Nina, CPC says between November and January, there is an increased chance of above-average temperatures across the south-central U.S. with the odds favoring below-average temperatures over the north-central U.S. "Also, above-average precipitation is favored across the northern tier of states, excluding New England, and drier-than-average conditions are more probable across the southern tier of the U.S."
Juli says: The outlook for La Nina to continue through the winter does not bode well for lasting drought relief in the Southern Plains, signaling the crop will come out of dormancy in tough shape this spring. It will take timely rains to lift crop conditions as the crop develops. Meanwhile in the Midwest, the odds of above-normal precip this winter should help to alleviate drought in the western Corn Belt.