May 22 - July 30
The Anatomy of a Significant Freezing Rain Event
Melanie R. Jones, Heather D. Reeves, and Daniel D. Tripp
What is already known:
- Freezing rain is rain that falls as a liquid but freezes into an icy glaze upon contact with the ground.
- This type of precipitation is very hazardous to one’s everyday life, particularly regarding all modes of transportation.
- Freezing rain events are difficult to accurately predict because they are extremely sensitive to minor temperature inflections within the atmosphere.
What this study adds:
- The lead times of Winter Storm Warnings, during this specific storm from January 4th-7th, generally increased from western Weather Forecast Offices (WFOs) to eastern WFOs as the storm traversed from west to east.
- Freezing rain frequently happens along with other forms of precipitation, making it difficult to truly know when freezing rain is done occurring during winter storms.
- During this storm, the timing of the onset of precipitation was well predicted, although ice accumulations were sometimes underpredicted.
Abstract:
The objective of this project was to examine a winter storm that occurred from January 4th to January 7th of 2025. This storm produced freezing rain accumulations from Kansas to the Maryland/Virginia coastline as it traversed across the United States. Winter Storm Warnings (WSWs) issued by the National Weather Service and precipitation types from the Automated Surface Observation Systems were analyzed herein. Timelines were constructed to visually observe how precipitation types and occurrences corresponded to the timing of WSWs. A comparison of forecasted ice accumulations and measured ice accumulations was also conducted. It was found that, for this winter storm, precipitation frequently began and ended as snow, with much of the freezing rain occurring between the snowfall. For most of the WSWs assessed, precipitation began to be observed after or near the time the warnings went into effect. It was also found that lead times generally increased from west to east. Finally, forecasted ice accumulations were accurate most of the time. It was more common to see forecasted amounts being too low compared to too high.