Current Research Projects
Project: CAREER: Toward a Global Understanding of Severe Convective Environments
Funded Period: June 2020 - May 2025
Project Details
Severe convective storms (SCS) produce damaging hail, intense wind gusts, and tornadoes that can result in significant losses, injuries, and fatalities. They pose a threat on every continent except Antarctica. Current observations of SCS are very sparse, and data records are limited. As such, our knowledge of where, why, and how often SCS occur globally is lacking. To address these difficulties, parameters derived from atmospheric conditions that foster SCS development (that is, favorable environments) have been used to assess SCS likelihood. Without these environments, developing storms will struggle to become SCS. The impacts of SCS are expected to grow with sprawling population centers and as favorable environments become more frequent with the warmer climate. This proposal aims to characterize the development of favorable environments across the globe and how global warming affects their development. While shedding light on the potential for SCS formation worldwide, this research may improve SCS forecasts and help manage risks and exposures to SCS. To this end, this research can provide a new and fundamental understanding of the underlying frequency and processes leading to the SCS development and in response to a warming climate at previously unexplored resolutions. Integrating research and education, this proposal will focus on bringing a global perspective to SCS and climate change education, and improve the understanding of risk to property, agriculture and people by developing interactive educational resources and online modules.
Group Members Involved
Dr. John T. Allen, Principal Investigator
Carlos Mario Cuervo Lopez, Graduate Research Assistant
Alan Jesus Garcia Rosales, Graduate Research Assistant
Mitchell Green, Undergraduate Research Assistant
Former Group Members
Dr. Leticia Oliveria dos Santos, Ph.D., Fullbright Brazil Scholar as Ph.D. Student
Scott Thomas, Undergraduate Research Assistant
Intellectual Merit & Outcomes
This project has delivered a wide variety of insights into the character of global thunderstorm environments and observations, including observational climatologies over Europe and the United States (Taszarek et al. 2020a, Journal of Climate, Elmore et al. 2022) exploring regional differences between the United States, Europe, South America, Australia and globally (Taszarek et al. 2020a, Zhou et al. 2021, Taszarek et al. 2021, Allen et al. 2021, Dos Santos et al. 2023). Notable contributions include illustrating the need to consider a variety of different environments if the end goal is to capture the global rate of occurrence (Zhou et al. 2021), the first tornado based environmental study over Australia (Allen et al. 2021, Monthly Weather Review), the first detailed proximity study of environments to observed storms in Brazil and eastern South America (Dos Santos et al. 2023), and a preliminary global climatology using ERA-5 (Taszarek et al. 2021).
Another area of focus has been in exploring how severe thunderstorm environments have been changing through time, with results suggesting that while convective potential is increasing over Europe driven by increases to instability over the past four decades, over the United States there is a decreasing frequency of thunderstorms and severe thunderstorms driven by rapid and large changes to convective inhibition (Taszarek et al. 2020b,BAMS). This signal has also been illustrated to vary continentally, but is mostly consistent between different reanalysis datasets (Taszarek et al. 2021, Pilguj et al. 2022).
Extending toward future projections, we co-developed a comprehensive global analysis of changes to severe convective storms under future climates projected using CMIP6 (Lepore et al. 2021), which illustrated large differences in the expected changes between the U.S. and other continents, and provided novel insights into how these hazards are expected to change as a function of temperature. Finally a review of expectations for hail under climate change was also produced (Raupach et al. 2021), and work is ongoing towards providing a similar summary of knowledge for tornadoes.
Ongoing work has focused on four key areas: providing a comprehensive assessment of severe thunderstorm environments from multiple reanalyses, extending what we know about projections of a warming climate globally (Allen et al. 2023) characterizing sources and sinks of instability using the lapse rate tendency (Rosales and Allen 2023), and a detailed global evaluation of reanalysis performance compared to observations (Lopez et al. 2023), that builds on initial work that has evaluated reanalysis derived convective variables against observed sounding data have suggested that new generation products such as the ERA5 and MERRA2 reanalyses provide high quality profiles for this application (Taszarek et al. 2020c, Journal of Climate).
Broader Impacts
Two Ph.D. students and four undergraduate students have been supported, and the project has facilitated a year-long research visit from a Fullbright Brazil Ph.D. student scholar whom the PI co-advises. Two opinion editorial pieces written by the PI about the state of climate change and severe weather research were featured on The Conversation, Scientific American and PBS.com \citep{ConversationArt}. The PI has provided commentary and interviews on dozens of occasions on this topic. Publications: Eleven peer-reviewed publications, ten invited talks and 20 conference presentations have resulted from this project. Research Product Availability: Publications and a summary of results are available on the project website and respective journal websites. Code for calculating convective quantities over large gridded datasets has been made available at GitHub (https://github.com/xgcm/xcape). Data from the analysis of future climate projections in CMIP6 is published in an online google cloud repository through PANGEO.
Publications
Dos Santos*, L. O, Nascimento, E., and Allen, J. T., 2023: Discriminant Analysis for Severe Storm Environments in South-central Brazil. Monthly Weather Review., 151, 2659–2681. doi: 10.1175/MWR-D-22-0347.1
Elmore, K., Allen, J. T., Gerard, A., 2022: Sub-Severe and Severe Hail. Weather and Forecasting, 37(8), 1357-1369. doi: 10.1175/WAF-D-21-0156.1
Pilguj, N., Taszarek, M., Allen, J. T., Hoogewind, K., 2022: Are Trends in Convective Parameters over the United States and Europe Consistent between Reanalyses and Observations? Journal of Climate, 35, 3605-3626. doi: 10.1175/JCLI-D-21-0135.1
Zhou, Z., Q. Zhang, J. T. Allen, X. Ni and C. Ng, 2021: How many types of severe hailstorm environments are there globally? Geophysical Research Letters, 48, e2021GL095485. doi: 10.1029/2021GL095485
Lepore, C., Abernathy, R., Henderson, N., Allen, J. T., Tippett, M. K., 2021. Future Global Convective Environments in CMIP6 Models. Earth’s Future, 9, e2021EF002277. doi: 10.1029/2021EF002277. (Research Highlight EOS: Stanley, S. (2022), Rising trend predicted for conditions linked to severe storms, Eos, 103, doi: 10.1029/2022EO220037.)
Taszarek, M., Pilluj, N., Allen, J. T., Gensini, V. A. Brooks, H. E., and P. Szuster, 2020: Comparison of convective parameters derived from ERA5 and MERRA2 with sounding data over Europe and North America. Journal of Climate, 34, 3211-3237. doi: 10.1175/JCLI-D-20-0484.1
Taszarek, M., Allen, J. T., Brooks, H., Czernecki, B., N.Pilguj, 2020: Differing trends in United States and European severe thunderstorm environments in a warming climate. Bulletin of the American Meteorological Society, 1-51. doi: 10.1175/BAMS-D-20-0004.1 PDF
Taszarek, M., Allen, J. T., Groenemeijer, P., Edwards, R., Brooks, H. E., Chmielewski, V., Enno, S., 2020: Severe Convective Storms Across Europe and the United States. Part 1: Climatology of lightning, large hail, severe wind and tornadoes. Journal of Climate, 33, 10239-10261. doi: 10.1175/JCLI-D-20-0345.1. PDF
Raupach, T. H, Martius, O., Allen, J. T., Kunz, M., Lasher-Trapp, S., Mohr, S., Rasmussen, K. L., Trapp, R. J., and Q. Zhang, 2020: The effects of climate change on hailstorms. Nature Reviews Earth and Environment, 2, 213-226. PDF
Allen, J. T., E. R. Allen, H. Richter and C. Lepore, 2021: Australian Tornadoes in 2013: Implications for Climatology and Forecasting. Monthly Weather Review, 149, 1211-1232. doi: 10.1175/MWR-D-20-0248.1
Taszarek, M., Allen J. T., Marchio, M. and H. E. Brooks, 2021: Global Climatology and Trends in convective environments from ERA5 and rawinsonde data. NPJ Climate and Atmospheric Science, 4, 35. doi: 10.1038/s41612-021-00190-x PDF
Invited Presentations
Allen, J. T., 2023: Severe Thunderstorm Hazards and PV: Assessing Risk Now and in the Future, Invited Talk and Panel, DOE Photo-Voltaic Reliability Workshop (PVRW) 2024, Denver, Colorado. February 2024.
Allen, J. T., 2023: Statistical Downscaling for Global Relationships Between the Climate System and Severe Thunderstorms, Invited National Weather Center Colloquium, School of Meteorology, University of Oklahoma. December 2023.
Allen, J. T., 2023: Severe Convective Storms: Local Problems with Global Connections. Stout Lecture, Department of Earth and Atmospheric Sciences, University of Nebraska. February 2023.
Allen, J. T., 2022: Severe Convective Storms: Local Problems with Global Connections. Invited Seminar, Department of Geological and Atmospheric Sciences, Iowa State University (Virtual). November 2022.
Allen, J. T., 2022: Severe Convective Storms: Local Problems with Global Connections. Invited Seminar, Department of Earth, Ocean and Atmospheric Science, Florida State University (Virtual). November 2022.
Allen, J. T., 2022: Global Perspectives on the Relationship between the Climate System and Severe Thunderstorms. Invited Seminar, Department of Atmospheric Science, University of Wyoming. October 2022.
Allen, J. T., 2022: Moderator: Panel ‘From Climatology to Climate Change: The Changing Picture of Hail and Hailstorms’. 2nd North American Hail Workshop, August 13-15th 2018, Boulder CO.
Allen, J. T., 2022: Global Perspectives on Hail and Severe Thunderstorms. Invited Keynote, Severe and Extreme Convective Storms, 2022 CMOS-CGU-ESC Joint Congress, Virtual. June 2022.
Allen, J. T., 2022: Global Perspectives on the Relationship between the Climate System and Severe Thunderstorms. Invited Seminar, Purdue University EAPS. April 2022.
Allen, J. T., 2022: Climate Exchange and Extremes. Invited Panelist, Verisk Envision 2022, Miami Beach, FL, April 2022.
Allen, J. T., 2020: Global Observations and Risk of Convective Storms. Invited Presentation, ESSL Workshop on Convective Storms Risk. 24th November 2020.
Presentations
Rosales*, A. G., and J. T. Allen, 2024: Evaluation of Severe Local Storm Environments in Australia Using the Lapse Rate Tendency Equation. 37th Conference on Climate Variability and Change, 104th Annual Meeting of the American Meteorological Society, Baltimore, Maryland.
Cuervo Lopez*, C. M., J. T. Allen*, M. Taszarek, 2024: Comparative Analysis of ERA5 Model Levels and Pressure Levels Over the Continental U.S. 28th Conference on Integrated Observing and Assimilation Systems for the Atmosphere, Ocean, and Land Surface, 104th Annual Meeting of the American Meteorological Society, Baltimore, Maryland.
Rosales*, A. G., J. T. Allen, 2023: Evaluation of Severe Storm Environments through use of the Lapse Rate Tendency Equation. Poster and Extended Abstract. WCRP Open Science conference. Kigali, Rwanda. 23-27 October 2023.
Rosales*, A.G., and J. T. Allen, 2023: Evaluation of the Evolution of Severe Storm Environments through Use of the Lapse Rate Tendency Equation. 20th AMS Conference on Mesoscale Processes, Madison, Wisconsin.
Allen, J. T., Gopalakrishnan, D., Cuervo-Lopez*, C., Trapp, R. J, and E. Robinson, 2023: Comparing CMIP6 Future Projections for Severe Convective Environments in a Warmed Climate over Australia, Europe, and North America. 11th European Conference of Severe Storms, Bucharest, Romania.
Taszarek, M., Allen, J. T., Nixon*, C., Dowdy, A. and F. Battaglioli, 2023: Do severe storms across Australia, Europe, and the United States share similiarities? A comparison of atmospheric profiles and environmental predictors. 11th European Conference of Severe Storms, Bucharest, Romania.
Allen, J. T., Lepore, C., Abernathy, R., Henderson, N., Tippett, M. K., 2022: Global Climatology of Severe Storm Environments and Future Projections Under a Warming Climate. 30th AMS Conference on Severe Local Storms, Santa Fe, New Mexico.
Cuervo Lopez*, C. M., J. T. Allen, M. Taszarek, 2023: Evaluation of Reanalyses relative global performance for convective parameters using Self Organizing Maps (SOM).Poster, 2nd Symposium on Community Modeling and Innovation, 103rd Annual Meeting of the American Meteorological Society, Denver, Colorado.
Rosales*, A. G., and J. T. Allen, 2023: Evaluation of Severe Storm Environments through use of the Lapse rate tendency equation. Poster, 3rd Symposium on Mesoscale Processes, 103rd Annual Meeting of the American Meteorological Society, Denver, Colorado.
Cuervo Lopez*, C. M., J. T. Allen, M. Taszarek, 2022: Evaluation of Reanalyses relative global performance for convective parameters using Self Organizing Maps (SOM). Poster, 30th AMS Conference on Severe Local Storms, Santa Fe, New Mexico.
Rosales*, A. G., and J. T. Allen, 2022: Evaluation of Severe Storm Environments through use of the Lapse rate tendency equation. Poster, 30th AMS Conference on Severe Local Storms, Santa Fe, New Mexico.
Dos Santos*, L. O, Nascimento, E., and J. T. Allen, 2022: A Long-Term Climatology of Environments Conducive to Severe Storms in Subtropical South America. Poster, 30th AMS Conference on Severe Local Storms, Santa Fe, New Mexico.
Cuervo Lopez*, C. M. and J. T. Allen, 2022: Objective Evaluation of Reanalysis-Derived Convective Profiles. Kevin Trenbeth Symposium, 102nd Annual Meeting of the American Meteorological Society, Virtual Poster.
dos Santos*, L. O., Nascimento, E. and J. T. Allen, 2022: Convective Environments Associated with Severe Weather Reports in South-Central Brazil. 19th Conference on Mesoscale Processes, 102nd Annual Meeting of the American Meteorological Society, Virtual Poster.
Taszarek, M., Pilluj, N., Allen J. T., Gensini, V. A. Brooks, H. E., and K. Hoogewind, 2022: Comparison of Convective Parameters Derived from ERA5 and MERRA-2 with Rawinsonde Data over Europe and North America. 21st Conference on the Middle Atmosphere, 102nd Annual Meeting of the American Meteorological Society, Virtual Oral Presentation.
Taszarek, M., Allen, J. T., Pucik, T., Hoogewind, K., and H. E. Brooks, 2022: Severe Convective Storms across Europe and the United States. Part II: ERA5 Environments Associated with Lightning, Large Hail, Severe Wind and Tornadoes. 19th Conference on Mesoscale Processes, 102nd Annual Meeting of the American Meteorological Society, Virtual Poster.
Taszarek, M., Allen, J. T., Groenemeijer, P., Edwards, R., Brooks, H. E., Chmielewski, V., Enno, S., 2022: Severe Convective Storms Across Europe and the United States. Part 1: Climatology of lightning, large hail, severe wind and tornadoes. 19th Conference on Mesoscale Processes, 102nd Annual Meeting of the American Meteorological Society, Virtual Poster.
Allen, J. T., 2020: Global Observations and Risk of Convective Storms. Invited Presentation, ESSL Workshop on Convective Storms Risk. 24th November 2020.
Allen, J. T., Taszarek, M., Marchio, M., Brooks, H., Pilguj, N., Lepore, C., 2021: Global decreases in favorable thunderstorms environments: Trends and variability. Australian Meteorological and Oceanographic Society Annual Meeting 2021: Science for Impact, Virtual.
Raupach, T. H, Martius, O., Allen, J. T., Kunz, M., Lasher-Trapp, S., Mohr, S., Rasmussen, K. L., Trapp, R. J., and Q. Zhang, 2021: Hail in a warming climate. 3rd European Hail Workshop, Virtual.
Murillo, E., Homeyer, C. and Allen, J. T., 2021: United States hail climatology: How good can we get? Invited Presentation, 3rd European Hail Workshop, Virtual.
Media Contributions
Allen, J. T., 2021: Tornadoes and climate change: What a warming world means for deadly twisters and the type of storms that spawn them. The Conversation – Op-Ed. Published: December 13th 2021. Republished at PBS.org, Scientific American, and many other outlets.
Allen, J. T., 2021: I study tornadoes. We need to know more about how they’re affected by climate change.USA Today – Op-Ed. Published: December 13th 2021.
