Dr. Mark R. Anderson
Date of this Version
Rick, N., 2020: Case Studies of Colorado Lows and the Impacts on Winter Weather Maintenance M.S. Thesis, Dept. of Earth and Atmospheric Sciences, University of Nebraska, 136 pp.
Winter storms of varying degrees plague the Plains each year, bringing with them ice, snow, wind, and cold temperatures which adversely affect public, commercial, and private transportation alike. The Nebraska Department of Transportation (NDOT) adopted a Maintenance Decision Support System (NDOT-MDSS) to aid in their winter weather maintenance practices. NDOT-MDSS ingests data from a variety of numerical weather models as well as real time surface and pavement observations to output both a weather forecast and winter road maintenance recommendation that can be taken into account by NDOT to finalize their maintenance decisions for a specific storm system or road segment. Two case studies of winter storm events, 24-25 November 2018 and 23-25 February 2019 that affected Lincoln, NE were analyzed. The case studies were chosen because they were both Colorado low systems that followed very similar synoptic scale trajectories yet produced very different results. An initial synoptic overview that preceded each system was conducted in order to understand the observed environment prior to snowfall onset for each case study. After the synoptic analysis, comparison of the NDOT‑MDSS forecasts at 3, 6, 9, and 12 hours prior to snowfall intervals to the observed ASOS values at the Lincoln, NE airport (LNK) were conducted. Forecasted snowfall amount analysis of the NDOT-MDSS was analyzed against the Rapid Refresh model (RAP), 12 km North American mesoscale model (12 km NAM), 4 km North American mesoscale model (4 km NAM), the global forecast system (GFS), and a derived model average, as well as National Weather Service and Weather Prediction Center computed accumulation forecasts. Ultimately, these analyses aided in a better understanding of the meteorological forecasts produced by the NDOT-MDSS and resulted in more insight for NDOT on the benefits and limitations of the NDOT-MDSS system that they have embraced.
Advisor: Mark R. Anderson