HOUSTON – As winter approaches, the climate pattern known as La Niña is predicted to form, though it is expected to be a weak La Niña this year. La Niña typically begins when cooler-than-average temperatures develop in the central and eastern Pacific Ocean, off the coast of South America. This cooling phase impacts global weather patterns throughout the world by changing the strength and location of the jet stream. The blue areas in the sea-surface temperature anomaly map below represent below-average temperatures. You can watch this video of me explaining how La Niña is expected to affect us this winter.