When La Niña is in effect, wetter than usual conditions are common in the Great Lakes region during winter. There is a 60% chance for a weak and short duration La Niña to emerge between September and November and persist into January to March, according to the National Weather Service's Climate Prediction Center.

A weak La Niña is expected this winter, federal experts say. Drier-than-average conditions are likely in the Southwest, but California's outlook is uncertain.