(Top) Geopotential height anomalies (m) at the 500 hectopascal (hPa) pressure level during January–May 2021. Cold colors indicate below-average atmospheric pressure and warm colors indicate above-average atmospheric pressure at a level about three miles above the Earth’s surface. (Bottom) The average 500 hPa geopotential height anomalies from January–May for the 9 strongest La Niña episodes since 1950. Note the different scaling between the top and bottom figures. The top figure has a wider range of values because the top figure includes contributions from both predictable signals, like La Niña, and random weather variability, whereas the bottom figure has filtered out most of the random weather variability. Anomalies are calculated with respect to the 1991-2020 base period. Figure by John Allen and NOAA Climate.gov with NCEP/NCAR Reanalysis data obtained from the NOAA Physical Sciences Laboratory.