Forecasts are already showing a possibility of La Niña in our future, with the Climate Prediction Center for the National Weather Service rating our chances at about 70 percent. The system is predicted to be weak and short-lived, possibly arriving early next month. La Niña is not expected to make it through the winter, and forecasters gave it about a 55 percent chance of it lasting past December. Why the uncertainty? La Niña depends on different factors, including ocean water temperature along the central Pacific.