Freezing rain events, which have caused billions of dollars in damage in recent decades, are still one of the least understood forms of precipitation. These events affect both urban and rural regions, including cities and forests.
However, the often short-lived and sporadic occurrence of these events poses significant challenges to accurate reporting, complicating analysis attempting to fill this knowledge gap.
Through the utilization of ERA5 Reanalysis from 1979–2020 as a proxy for lacking ground truth data, freezing rain events were identified and analyzed throughout eastern North America. These events were then sorted into full area and sub-area regimes through a multivariate Self-Organizing Maps (SOM) analysis.
This classification of regimes and their subsequent analysis showed the varying importances of the initial synoptic states of each event and provides examples of distinct synoptic structures associated with freezing rain events impacting different regions of eastern North America.
In addition, our regime classification identified the prevalence of extreme events associated with each regime. This SOM approach can also be configured to more regional scales to provide more granularity to specific regions of eastern North America.
Britton, A. R., & Mullens, E. D. (2025). Temporal and Spatial Analysis of Freezing Rain Regimes over Eastern North America. Journal of Applied Meteorology and Climatology, 1, JAMC-D-24-0173.1.