Understanding Heat Wave–Snow Drought Relationships Across the Western United States
Droughts are one of the most costly and impactful environmental hazards in the United States. Drought impacts on water resources and ecosystems in the western U.S. are becoming more amplified as mountain snowpacks continue to diminish and late spring and early summer season heat waves occur more frequently. The connection and compounding nature of these two drought drivers has not been well studied.
This project will investigate how late spring and early summer heat waves rapidly reduce snowpack and influence the magnitude, extent, and persistence of snow drought conditions in the western United States. This research will also link heat wave–snow drought occurrences (in isolation and simultaneously) to runoff and streamflow variability and temperature.
To achieve this, the research team will leverage several NOAA data products, including the recently updated Twentieth Century Reanalysis Version 3 (20CRv3) and National Water Model, to understand:
- How well snowmelt season heat wave events are represented at various spatiotemporal scales
- To what extent heat waves influence snow conditions and trigger the onset of snow drought conditions
- The relative influence of heat wave-induced changes to snowpack on runoff and streamflow characteristics, soil moisture, and downstream reservoir conditions.
This project is part of the MAPP/NIDIS-supported Drought Task Force V.
Research Snapshot
Laurie Huning, California State University, Long Beach
Alan Rhoades, Lawrence Berkeley National Laboratory; Dan McEvoy, Desert Research Institute, Western Regional Climate Center
What to expect from this research
- Presentations at scientific conferences, practitioner and management focused conferences (e.g., Annual Meeting on California Cooperative Snow Surveys), and at western Drought Early Warning System (DEWS) events
- Peer-reviewed journal publications focused on (1) heat wave definitions focused on snowmelt, (2) assessment of heat wave-induced or amplified snow-drought on watershed hydrology, and (3) evaluation of historic snowmelt season heat waves using the full ensemble of the 20CRv3.
- Open access archive of project analysis scripts and snow drought and heat wave event catalogs derived from the NOAA data products used.
- Summary two-pagers for public consumption highlighting key findings from each manuscript, which will be available through the Drought.gov Snow Drought web page.
- Mentored training to graduate students in the areas of snow hydrology, extreme event analysis, and hydrometeorology at California State University, Long Beach.
