Assessing ENSO Summer Teleconnections, Impacts, and Predictability in North America

Abstract During the summer when an El Niño event is transitioning to a La Niña event, extratropical teleconnections exert robust warming anomalies over U.S. Midwest threatening agricultural production. This study assesses performance of current climate models in capturing prominent observed responses North America during summer, based on atmospheric general circulation model experiments and coupled from American Multimodel Ensemble (NMME). The ensemble mean SST-forced across summers does not capture Midwest. do produce consistent subtropical western Pacific (WP) negative precipitation this leads poor simulations America. In NMME models, with active air–sea interaction, WP show better agreement observations. However, downstream wave train pattern resulting exhibit large disagreement are consistently weaker than Furthermore, these anomalous anticyclone robustly translate into warm anomaly Midwest, work suggests that, interaction important simulating tropical WP. Nevertheless, skillful representations Rossby propagation land–atmosphere processes also essential for