Image caption
Beneath the surface of the tropical Pacific Ocean at the equator, a deep pool of cooler-than-average (blue) waters has been building up over the past couple of months (July 12–Sept. 5, 2024). This pool of relatively cool water is a key factor behind the prediction for La Niña later this fall and winter. NOAA Climate.gov image, based on analysis from Michelle L'Heureux, Climate Prediction Center.