Extreme U.S. Great Plains heat waves are linked to East Asian Monsoon

Heat waves are the leading weather‐related cause of death in the U.S. For example, the most recent U.S. extreme heat waves that occurred over the Great Plains in 2011 and 2012 caused 362 deaths. These events are unusual and largely unpredictable beyond the synoptic time scale. However, their number and severity have increased and are projected to continue to increase. Therefore, there is a dire need to identify physical processes that modulate the U.S. heat waves in order to improve prediction and future projection. A new study published on line in Journal of Geophysical Research: Atmospheres used both observational data and model simulations to find that convective latent heat release from the East Asian Monsoon forces an equivalent barotropic wave train along the subtropical jet stream, promoting an anticyclonic circulation pattern over the Great Plains. This anticyclone serves as a blocking pattern for transient synoptic‐scale systems supporting persistent drought and clear sky conditions, and thus enhances the likelihood of extreme droughts and heat waves over the U.S. Great Plains.

Lopez, H., S.-K. Lee, S. Dong, G. Goni, B. Kirtman, R. Atlas and A. Kumar, 2019: East Asian Monsoon as a modulator of U.S. Great Plains heat waves. J. Geophys. Res. Atmos., 24, https://doi.org/10.1029/2018JD030151. https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JD030151