Synoptic Forcing of Observed Warm Seasons Heat Stress in the United States.

The Midwestern United States often experiences intense heat stress during the warm season, which can severely impact public health, agriculture, and infrastructure. Heat waves during the warm season are linked to certain large-scale weather patterns, like high pressure ridges in the middle troposphere that cause sinking air motion over a broad region. Studying the large-scale atmospheric patterns that lead to these extreme heat events is crucial for improving forecasting and developing effective prevention measures. The study uses ERA5 reanalysis data to examines the mechanisms related to continental-scale weather patterns that drive the observed historical heat stress events in the Midwestern U.S. Particular attention was given to high-pressure systems, blocking patterns, and persistent ridging, which are known to contribute to prolonged periods of extreme heat. By examining the temporal and spatial distribution of these synoptic features, we gain insights into the variability and frequency of heat stress events across the region. The result indicates that synoptic-scale circulation patterns are strongly correlated with the occurrence of warm season heat stress. Understanding the synoptic forcing of heat stress in the Mid-western United States is crucial for formulating effective adaptation strategies to cope with extreme heat events and for informing policy decisions aimed at reducing the impacts of climate change on this vulnerable region.

Keywords: heat stress, extreme heat events, synoptic forcing, Mid-western United States, climate models, atmospheric circulation