Publication Date

2025

Advisor(s) - Committee Chair

Zachary Suriano, Jason Polk, Xingang Fan

Degree Program

Department of Earth, Environmental, and Atmospheric Sciences

Degree Type

Master of Science

Abstract

Rain-on-snow events, characterized by rain falling on existing snowpack, have the potential to bring about significant hydrological and environmental impacts including snowmelt, flooding, landslides, and other natural hazards. Despite prior evidence suggesting the Connecticut River Watershed has endured socioeconomic and environmental setbacks due to rain-on-snow events in the past, limited prior research has been performed on the role of rain-onsnow events within the region’s hydroclimatology. Gaining a deeper understanding of the occurrence and impacts of such events would provide valuable insights for risk and water resource managers. The purpose of this research was to create a climatology of rain-on-snow events in the Connecticut River Watershed, with particular emphasis on quantifying spatiotemporal variability, trends, and hydrological impacts, while also analyzing two trios of case study events to study differences in hydrological response between a rain-on-snow, nonrain- on-snow, and precipitation event. The data collected include gridded observations of snow water equivalent, precipitation, and temperature, and stream gage height data. Rain-on-snow events were identified in the region, followed by an analysis of their frequency, intensity, and temporal patterns. Results revealed that the frequency of rain-on-snow events and the average magnitude of snow water equivalent loss increased as elevation increased, while precipitation decreased with increasing latitude. There were significant decreasing trends in rain-on-snow frequency for parts of Vermont and Massachusetts, significant increasing (decreasing) trends in snow water equivalent loss for parts of the lower (upper) watershed, and significant increasing trends in precipitation for many parts of the watershed. Finally, for the Passumpsic Sub-Basin case study, magnitude of gage height response for the rain-on-snow event was approximately double that of the non-rain-on-snow event. The findings from this research will play a crucial role in future mitigation strategies, water resource management, and resilience within the watershed.

Disciplines

Atmospheric Sciences | Climate | Earth Sciences | Hydrology | Meteorology | Oceanography and Atmospheric Sciences and Meteorology | Physical Sciences and Mathematics

Available for download on Friday, May 08, 2026

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