University of Wisconsin–Madison

The Wisconsin Rainfall Project

UW-Madison Project Leads:

  • Daniel Wright, PhD, Assistant Professor, Civil and Environmental Engineering
  • David Lorenz, PhD, Associate Scientist, Nelson Institute Center for Climatic Research


Planning and design of infrastructure including detention ponds, dams, bridges, and culverts depends on rainfall statistics such as the “100-year storm.” Recent UW-Madison research has shown that existing rainfall statistics including those from the National Weather Service’s Atlas 14 are badly out date due to recent increases in the severity of extreme storms (see Figure 1). The long-term resiliency of Wisconsin’s infrastructure depends on updating these statistics to reflect both present-day and future conditions. This information will (ultimately) help engineers and planners systematically prioritize infrastructure investment.

Figure 1: (left) The depth of the largest rainfall event for each year, 1961 through 2018 in West Madison. The magnitude has increased by 30% over this time. (right) the number of days per year, 1961 through 2018, that had greater than 2 inches of rain in West Madison. The frequency of such days has doubled over this time.

The Wisconsin Rainfall Project is a proposed science/engineering effort from UW-Madison and the Wisconsin Initiative on Climate Change Impacts (WICCI) aimed at producing three components of rainfall information for the infrastructure sector:

  • Component 1: “Present day” rainfall statistics: We will use the RainyDay software to generate updated rainfall design statistics for 2- to 1000-years. Preliminary results (above) highlight the much larger estimates of 100-year rainfall from RainyDay, which uses more recent data than the widely-used Atlas 14.
  • Component 2: “Future climate” rainfall statistics using UW Probabilistic Downscaling: We will use the UW Probabilistic Downscaling approach combined with the latest generation of climate model projections to generate 2- to 1000-year rainfall statistics for the years 2050 and 2075.
  • Component 3: “Hyperresolution” rainfall data: We will use the Hydro-NEXRAD radar processor to create a first-of-its-kind rainfall dataset of major recent storms around the state (June 2008, July 2010, August 2018, and others) at the resolution needed for flood modeling.

    Figure 2: Comparison of Atlas 14 precipitation predictions (left) with those from the RainyDay software (middle). The difference between the predictions is shown on the right.

Technical Advisory Committee: A Technical Advisory Committee (TAC)  has been assembled in order to ensure the quality and usefulness of the project outputs. TAC members have been recruited from the recently-formed WICCI Infrastructure Working Group, and have substantial expertise in infrastructure design and planning. The TAC includes members from the Wisconsin Department of Transportation, American Public Works Association, The Southeastern Wisconsin Regional Planning Commission, The Cities of Madison and Brookfield, Emmons & Olivier Resources Inc., and other organizations.