North American Extreme Winter Weather and the Polar Vortex

Extreme cold weather events during winter in North American can cause huge damages in society’s infrastructure and people’s daily life. Examples of cold spells in recent North American history include the cold extremes happened in 14-18 January 2005 and 20-28 December 2022. Persistent anomalies in the polar vortex (PoV) strength and location are associated with a robust and persistent regional surface weather response. Our goal is to learn more about how the PoV provides useful information for understanding of cold air outbreak (CAO) type events, to understand the incomplete relationships between the polar vortex strength and location on the occurrence of CAOs, and how PoV displacements and their splitting/stretching will impact the severity of CAOs in North America. Because of the importance of stratosphere–troposphere coupling for seasonal climate predictability, identifying the type of stratospheric variability to capture the correct surface response will be necessary. In this study we will present our case studies of the observed extreme cold air outbreak events and its connection with Polar Vortex.