Abstract 035

Abstract ID: 035

Prediction and Impacts of 14-day Extreme Precipitation Periods within the CONUS

Lead Author: Melanie Alayne Schroers
School of Meteorology, University of Oklahoma, United States of America

Keywords: Extreme Precipitation, Impacts, S2S Verification

Abstract: Long periods of extreme precipitation can cause costly damages to a region’s infrastructure, while also creating a higher risk for the region’s population. Planning for these periods would ideally begin at the subseasonal to seasonal (S2S) time scale, yet prediction of precipitation at this time scale has low skill. A database of 14-day extreme precipitation periods across 16 North American regions (clusters) was used to understand more about the prediction of synoptic variables, starting with 500hPa geopotential height anomalies, within S2S project models. Overall, the highest correlations within geopotential height prediction are seen within Week 1 and drop with lead time. Comparison between skill scores of geopotential height anomalies and precipitation anomalies show little correlation past Week 1. Historical impacts of these periods, using NCEI storm reports, were also assessed to benefit decision makers in future risk mitigation. A variety of reports were found during extreme periods, from winter weather reports in West Coast periods, to tropical storm reports in Southeast periods; with large differences in impacts seen between the wet and dry seasons. Although there is still much to learn about extreme precipitation periods, this study contributes to the foundational knowledge of synoptic drivers and impacts of periods.

Dr. Elinor Martin (School of Meteorology, University of Oklahoma & South Central Climate Adaptation Science Center)