Walker Ashley

Research Emphases

Meteorology, Climatology, Hazards, GIS

Specific Research Endeavors

I am an atmospheric scientist and physical geographer with interests in hazards and societal interactions, severe storms, and applied climatology and meteorology. My research focuses on:

  • understanding how human exposure and vulnerability contributes to weather-related disasters
  • how urbanization and other land covers/uses influence thunderstorm formation
  • radar-based climatologies of organized thunderstorms and 
  • weather hazard impacts on transportation systems.
In the past, I have investigated the climatology and hazards of widespread and long-lived windstorms known as derechos, the rainfall patterns of thunderstorm complexes, the importance of increasing population and suburban sprawl on tornado vulnerability, and the geographies of weather-related fatalities.

Frequently Taught Classes

  • GEOG 105: Weather, Climate, and You
  • GEOG 306: Severe and Hazardous Weather
  • GEOG 406/506: Natural Hazards and Environmental Risk
  • GEOG 498/600: GIS Applications in Meteorology and Climatology
  • MET 360: Radar Meteorology
  • MET 444/544: Mesoscale Meteorology

Representative Publications

  • Ashley, W. S., A. M. Haberlie, and J. Strohm, 2019: A climatology of quasi-linear convective systems and their hazards in the United States. Weather and Forecasting, 34, 1605-1631.
  • Haberlie, A. M., and W. S. Ashley, 2019: A radar-based climatology of mesoscale convective systems in the United States. Journal of Climate, 19, 1591-1605.
  • Haberlie, A. M., and W. S. Ashley, 2018: Climatological representation of mesoscale convective systems in a dynamically downscaled climate simulation. International Journal of Climatology, 39, 1144-1153.
  • Strader, S. M., and W. S. Ashley, 2018: Fine-scale assessment of mobile home tornado vulnerability in the Central and Southeast U.S. Weather, Climate, and Society, 10, 797–812
  • Strader, S. M., W. S. Ashley, T. J. Pingel, and A. J. Krmenec, 2017: Projected 21st century changes in tornado exposure, risk, and disaster potential. Climatic Change. DOI: 10.1007/s10584-017-1905-4
  • Ashley, W. S., and S. M. Strader, 2016: Recipe for disaster: How the dynamic ingredients of risk and exposure are changing the tornado disaster landscape. Bulletin of the American Meteorological Society, 97, 767-786.
  • Haberlie, A., W. S. Ashley and T. Pingel, 2014: The effect of urbanization on the climatology of thunderstorm initiation. Quarterly Journal of the Royal Meteorological Society. DOI: 10.1002/qj.2499.
  • Ashley, W. S., S. Strader, D. Dziubla and A. Haberlie, 2014: Driving blind: Weather-related vision hazards and fatal motor vehicle crashes. Bulletin of the American Meteorological Society. DOI: 10.1002/met.1482.
  • Ashley, W. S., S. Strader, T. Rosencrants and A. J. Krmenec, 2014: Spatiotemporal changes in tornado hazard exposure: The case of the expanding bull's eye effect in Chicago, IL. Weather, Climate and Society, 6, 175-193.
  • Ashley, W. S., M. L. Bentley, and J. A. Stallins, 2012: Urban-induced thunderstorm modification in the Southeast United States. Climatic Change, 113, 481-498.
  • Ashley, W. S., and C. W. Gilson, 2009: A reassessment of U.S. lightning mortality. Bulletin of the American Meteorological Society, 90, 1501–1518.
  • Ashley, W.S., A.J. Krmenec, and R. Schwantes, 2008: Vulnerability due to nocturnal tornadoes. Weather and Forecasting, 23, 795-807.
  • Ashley, S.T., and W.S. Ashley, 2008: Flood fatalities in the United States. Journal of Applied Meteorology and Climatology, 47, 805-818.
  • Ashley, W.S., 2007: Spatial and temporal analysis of tornado fatalities in the United States: 1880-2005. Weather and Forecasting, 22, 1214-1228.

Grants, Fellowships and Leaves of Absence

  • Collaborative Research: Observed and Future Dynamically Downscaled Estimates of Precipitation Associated with Mesoscale Convective Systems. With V. Gensini (NIU) and R. Schumacher (CSU). National Science Foundation, Climate & Large-scale Dynamics Program and Physical & Dynamic Meteorology Program, 2017-2020.
  • Tornadoes and Mobile Homes: An Inter-science Approach to Reducing Vulnerabilities and Improving Capacities for the Southeast's Most Susceptible Population. With S. Strader (Villanova) and K. Klockow (CIMMS). National Oceanic and Atmospheric Administration, 2017-2019.
  • Collaborative Research: Climatological and Event-based Radar Delineation of UHI Convection for Urban Corridors within the Southeastern U.S. With M. L. Bentley and J. A. Stallins. National Science Foundation, Geography & Regional Science Program and Physical & Dynamic Meteorology Program, 2007-2012.
  • NIU Undergraduate Research and Apprenticeship Program. Spring 2006, fall 2006-spring 2007, fall 2007-spring 2008, fall 2008-spring 2009, fall 2009-spring 2010, fall 2010-spring 2011, fall 2011-spring 2012, fall 2012-spring 2013, fall 2013-spring 2014, fall 2014-spring 2015.
  • NIU Research and Artistry Grant. Summer 2006, summer 2008, summer 2014, summer 2017.
  • NIU Undergraduate Research Assistantship. Summer 2014, spring 2015.
  • NIU Student Engagement Fund. Summer 2015, fall 2015, fall 2016, fall 2017.
  • NIU Great Journeys Assistantship. Fall 2014-spring 2015, fall 2015-spring 2016.


Presidential Teaching Professor

Certified Consulting Meteorologist 

Office: Davis Hall 219D



Ph.D.: University of Georgia


Contact Us

Geographic and Atmospheric Sciences
Davis Hall, Room 118
815-753-6872 (Fax)

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