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 21^st 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.