Large-scale atmospheric patterns can create favorable conditions for extreme events like heat waves and droughts. As the climate continues to warm due to human emissions, changes to the circulation may make some of those patterns more persistent and frequent. Here, we explore long-term changes in the large-scale atmospheric circulation over North America and the potential reasons behind these changes. We find that, during winter and spring, a specific atmospheric pattern is increasing in duration and frequency, which exacerbates extreme heat, drought, and fires over portions of North America. Climate projections are difficult to assess given model discrepancies with observations during most of the last century. These differences may be due to the models' misrepresentation of human emissions, the associated response, or natural modes of variability. However, climate models suggest that increases in these atmospheric patterns may be on the horizon once continued greenhouse gas emissions overwhelm other controlling factors like aerosols or internal variability.