NSSL Staff Profiles

Dr. Adam J. Clark is a federal research meteorologist at the National Oceanic and Atmospheric Administration’s (NOAA) National Severe Storms Laboratory (NSSL) in the Forecast Research and Development Division (FRDD) and an affiliate associate professor in the School of Meteorology at the University of Oklahoma.

Clark’s research involves developing model diagnostics, verification, and visualization strategies for high-resolution ensemble forecasts and exploring model physics sensitivities and predictability at convective scales. He is also one of the lead planners and facilitators for the annual NOAA Hazardous Weather Testbed Spring Forecasting Experiments. These experiments convene research and forecasting experts from around the world to improve predictions of severe weather hazards. As a part of this work, Clark collaborates with scientists from universities and other federal agencies, procures outside funding, interacts with operational forecasters within the National Weather Service and Storm Prediction Center, and advises/mentors students and early-career scientists.  He also worked for the Cooperative Institute for Mesoscale Meteorological Studies (CIMMS) at the University of Oklahoma from 2011 to 2015, and served as a National Research Council post-doc for NSSL from 2009 to 2011.

Selected Publications

Clark, A. J. and Coauthors, 2023: The 3rd Real-Time, Virtual Spring Forecasting Experiment to Advance Severe Weather Prediction Capabilities. Bull. Amer. Meteor. Soc., E456-E458 (https://doi.org/10.1175/BAMS-D-22-0213.1).

Roberts, B., A. J. Clark, I. L. Jirak, B. T. Gallo, C. Bain, D. Flack, J. Warner, C. S. Schwartz, and L. J. Reames, 2022: Model configuration vs. driving model: influences on next-day regional convection-allowing model forecasts during a real-time experiment. Wea. Forecasting (https://doi.org/10.1175/WAF-D-21-0211.1).

Clark, A. J., and E. D. Loken†, 2022: Machine-Learning-Derived Severe Weather Probabilities from a Warn-on-Forecast System. Wea. Forecasting, 37, 1721-1740.

Guerra, J. E., P. S. Skinner, B. Matilla, M. Flora, A. J. Clark, K. Knopfmeier, and A. Reinhart, 2022: Quantification of NSSL Warn-on-Forecast System Skill by Storm Age using Object-based Verification. Wea. Forecasting, 37, 1973-1983.

Gallo, B. T., K. A. Wilson, J. Choate, K. Knopfmeier, P. Skinner, P. Heinselman, I. Jirak, and A. J. Clark, 2022: Exploring the Watch-to-Warning Space: Experimental Outlook Performance during the 2019 Spring Forecasting Experiment in NOAA's Hazardous Weather Testbed. Wea. Forecasting, 37, 617-637.

Clark, A. J., and Coauthors, 2022: The 2nd Real-Time, Virtual Spring Forecasting Experiment to Advance Severe Weather Prediction. Bull. Amer. Meteor. Soc., E1114-E1116 (https://doi.org/10.1175/BAMS-D-21-0239.1).

Loken, E. D. †, A. J. Clark, A. McGovern, 2021: Comparing and Interpreting Differently-Designed Random Forests for Next-Day Severe Weather Hazard Prediction. Wea. Forecasting, 37, 871-899.

Hu, J., A. Fierro, Y. Wang, J. Gao, A. J. Clark, I. L. Jirak, E. Mansell, B. Roberts, E. James, and M. Hu, 2021: Assessment of Storm-Scale Real Time Assimilation of GOES-16 GLM Lightning-Derived Water Vapor Mas on Short Term Precipitation Forecasts during the 2020 Spring Forecast Experiment. J. Geo. Res, (https://doi.org/10.1029/2021JD034603).

Scaff, L., A. F. Prein, Y. Li, A. J. Clark, S. A. Krogh, N. Taylor, C. Liu, R. M. Rasmussen, K. Ikeda, and Z. Li, 2021: Dryline characteristics in North America’s historical and future climates. Clim. Dyn. https://doi.org/10.1007/s00382-021-05800-1

Wilson, K. A., B. T. Gallo, P. Skinner, A. J. Clark, P. Heinselman, & J. Choate, 2021: Analysis of end user access of Warn-on-Forecast guidance products during an experimental forecasting task, Weather, Climate, and Society, https://doi.org/10.1175/WCAS-D-20-0175.1.

Clark, A. J., and Coauthors, 2021: A Real-Time, Virtual Spring Forecasting Experiment to Advance Severe Weather Prediction. Bull. Amer. Meteor. Soc., E814-E816, https://doi.org/10.1175/BAMS-D-20-0268.1.

Roberts, B., B. T. Gallo, I. L. Jirak, A. J. Clark, D. C. Dowell, X. Wang, and Y. Wang, 2020: What Does a Convection-Allowing Ensemble of Opportunity Buy Us in Forecasting Thunderstorms.  Wea. Forecasting, 35, 2293-2316.

Gallo, B. T., J. Wolff, A. J. Clark, I. L. Jirak, L. R. Blank, B. Roberts, Y. Wang, C. Zhang, M. Xue, T. Supinie, L. Harris, L. Zhou, and C. Alexander, 2020: Exploring Convection-Allowing Model Evaluation Strategies for Severe Local Storms using the Finite-Volume Cubed-Sphere (FV3) Model Core. Wea. Forecasting, 36, 3-19.

Johnson, A., X. Wang, Y. Wang, A. Reinhart, A. J. Clark, and I. L. Jirak, 2020: Neighborhood and Object-based Probabilistic verification of the OU MAP Ensemble forecasts during 2017 and 2018 Hazardous Weather Testbeds. Wea. Forecasting, 35, 169-191.

Snook, N., F. Kong, A. J. Clark, B. Roberts, K. A. Brewster, and M. Xue, 2020: Comparison and verification of point-wise and patch-wise localized probability-matched mean algorithms for ensemble consensus precipitation forecasts.  Geophysical Research Letters, 47, https://doi.org/10.1029/2020GL087839.

Potvin, C., P. S. Skinner, K. A. Hoogewind, M. C. Coniglio, J. A. Gibbs, A. J. Clark, M. L. Flora, A. E. Reinhart, J. R. Carley, and E. N. Smith, 2020: Assessing systematic impacts of PBL schemes in the NOAA Warn-on-Forecast System. Mon. Wea. Rev., 148, 2567-2590.

Loken, E. D. †, A. J. Clark, and C. D. Karstens, 2020: Generating probabilistic next-day severe weather forecasts from convection-allowing ensembles using random forests. Wea. Forecasting, 35, 1605-1631.

Gallo, B. T., C. P. Kalb, J. Halley-Gotway, H. H. Fisher, B. Roberts, I. L. Jirak, A. J. Clark, C. Alexander, T. L. Jensen, 2019: Initial Development and Testing of a Convection-Allowing Model Scorecard. Bull. Amer. Meteor. Soc., 100, 367-384.

Clark, A. J., 2019: Comparisons of QPFs Derived from Single- and Multi-Core Convection-Allowing Ensembles. Wea. Forecasting, 34, 1955-1964.

Loken, E. D. †, A. J. Clark, A. McGovern, M. Flora, and K. Knopfmeier, 2019: Post-Processing Next-Day Ensemble Probabilistic Precipitation Forecasts Using Random Forests. Wea. Forecasting, 34, 2017-2044.

Clark, A. J., I. L. Jirak, B. T. Gallo, B. Roberts, K. H. Knopfmeier, R. A. Clark, J. Vancil, A. R. Dean, K. A. Hoogewind, P. L. Heinselman, N. A. Dahl, M. J. Krocak, J. J. Choate, K. A. Wilson, P. S. Skinner, T. A. Jones, Y. Wang, G. J. Creager, L. J. Reames, L. J. Wicker, S. R. Dembek, and S. J. Weiss, 2020: A Real-Time, Simulated Forecasting Experiment for Advancing the Prediction of Hazardous Convective Weather. Bull. Amer. Meteor. Soc., 0, (https://doi.org/10.1175/BAMS-D-19-0298.1).

Potvin, C. K., J. R. Carley, A. J. Clark, L. J. Wicker, P. S. Skinner, A. E. Reinhart, B. T. Gallo, J. S. Kain, G. S. Romine, E. A. Aligo, K. A. Brewster, D. C. Dowell, L. M. Harris, I. L. Jirak, F. Kong, T. A. Supinie, K. W. Thomas, X. Wang, Y. Wang, and M. Xue, 2019: Systematic Comparison of Convection-Allowing Models during the 2017 NOAA HWT Spring Forecasting Experiment. Wea. Forecasting, 34, 1395-1416.

Gallo, B. T., A. J. Clark, B. T. Smith, R. L. Thompson, I. Jirak, and S. R. Dembek, 2019: Incorporating UH occurrence Time to Ensemble-Derived Tornado Probabilities. Wea. Forecasting, 34, 151-164.

Loken, E. D. †, A. J. Clark, M. Xue, and F. Kong, 2019: Spread and Skill in Mixed- and Single-Physics Convection-Allowing Ensembles. Wea. Forecasting, 34, 305-330.

Roberts, B., I. L. Jirak, A. J. Clark, S. J. Weiss, and J. S. Kain, 2019: Post-Processing and Visualization Techniques for Convection-Allowing Ensembles. Bull. Amer. Meteor. Soc., 100, 1245-1258.

Adams-Selin, R. D., A. J. Clark, C. J. Melick, S. R. Dembek, I. L. Jirak, and C. L. Ziegler, 2019: Evolution of WRF-HAILCAST during the 2014-16 NOAA/Hazardous Weather Testbed Spring Forecasting Experiments. Wea. Forecasting, 34, 61-79.

Clark, A. J., I. L. Jirak, S. R. Dembek, G. J. Creager, F. Kong, K. W. Thomas, K. H. Knopfmeier, B. T. Gallo†, C. J. Melick, M. Xue, K. A. Brewster, Y. Jung, A. Kennedy, X. Dong, J. Markel, G. S. Romine, K. R. Fossell, R. A. Sobash, J. R. Carley, B. S. Ferier, M. Pyle, C. R. Alexander, S. J. Weiss, J. S. Kain, L. J. Wicker, G. Thompson, R. D. Adams-Selin, and D. A. Imy, 2018: The Community Leveraged Unified Ensemble (CLUE) in the 2016 NOAA/Hazardous Weather Testbed Spring Forecasting Experiment. Bull. Amer. Meteor. Soc., 99, 1433-1448.

Gallo, B. T. †, A. J. Clark, B. T. Smith, R. L. Thompson, I. Jirak, and S. R. Dembek, 2018: Blended Probabilistic Tornado Forecasts: Combining Climatological Frequencies with NSSL-WRF Ensemble Forecasts. Wea. Forecasting, 33, 443-460.

Coffer, B. E., M. D. Parker, J. M. L. Dahl, L. J. Wicker, and A. J. Clark, 2017: Volatility of Tornadogenesis: An Ensemble of Simulated Nontornadic and Tornadic Supercells in VORTEX2 Environments. Mon. Wea. Rev., 145, 4605-4625.

Clark, A. J., 2017: Generation of Ensemble Mean Precipitation Forecasts from Convection-Allowing Models. Wea. Forecasting, 32, 1569-1583.

Loken, E.†, A. J. Clark, M. Xue, and F. Kong, 2017: Comparison of Next-Day Probabilistic Severe Weather Forecasts from Coarse- and Fine-Resolution CAMs and a Convection-Allowing Ensemble. Wea. Forecasting, 32, 1403-1421.

Gallo, B.†, A. J. Clark, I. Jirak, J. S. Kain, S. J. Weiss, M. C. Coniglio, K. Knopfmeier, J. Correia, Jr., C. J. Melick, P. T. Marsh, A. R. Dean, M. Xue, F. Kong, K. W. Thomas, K. Brewster, D. Stratman, G. Carbin, W. Line, and R. Adams-Selin, 2017: Breaking new Ground in Severe Weather Prediction: The 2015 NOAA/Hazardous Weather Testbed Spring Forecasting Experiment, Wea. Forecasting, 32, 1541-1568.

Kain, J. S., S. Willington, A. J. Clark, S. J. Weiss, M. Weeks, I. L. Jirak, M. C. Coniglio, N. M. Roberts, C. D. Karstens, J. M. Wilkinson, K. H. Knopfmeier, H. W. Lean, L. Gilchrist, K. Hanley, R. North, and D. Suri, 2016: Collaborative Efforts between the U.S. and U. K. to Advance Prediction of High Impact Weather. Bull. Amer. Meteor. Soc., 98, 937-948.

Yussouf, N., J. S. Kain, A. J. Clark, 2016: Short-term Probabilistic Forecasts of the 31 May 2013 Oklahoma Tornado and Flash Flood Event Using a Continuous-Update-Cycle Storm-Scale Ensemble System. Wea. Forecasting, 31, 957-983.

Gallo, B. T.†, A. J. Clark, and S. R. Dembek, 2016: Forecasting Tornadoes Using Convection-Permitting Ensembles. Wea. Forecasting, 31, 273-295.

Iyer, E.†, A. J. Clark, M. Xue, F. Kong, 2016: A Comparison of 36-60 Hour Forecasts From Convection-Allowing and Convection-Parameterizing Ensembles. Wea. Forecasting, 31, 647-661.

Clark, A. J., A. MacKenzie, A. McGovern, V. Lakshmanan, R. Brown, 2015: An Automated, Multi-parameter Dryline Identification Algorithm Wea. Forecasting, 30, 1781-1794.

Hwang, Y.†, A. J. Clark, V. Lakshmanan, and S. E. Koch, 2015: Improved Nowcasts by Blending Extrapolation and Model Forecasts. Wea. Forecasting, 30, 1201-1217.

Clark, A. J., M. C. Coniglio, B. E. Coffer, G. Thompson, M. Xue, and F. Kong, 2015: Sensitivity of 24 h forecast dryline position and structure to boundary layer parameterizations in convection-allowing WRF model simulations. Wea. Forecasting, 30, 613-638.

Fierro, A. O., A. J. Clark, E. R. Mansell, D. R. MacGorman, S. R. Dembek, and C. L. Ziegler, 2015: Impact of Storm-Scale Lightning Data Assimilation on WRF-ARW Precipitation Forecasts during the 2013 Warm Season. Mon. Wea. Rev., 143, 757-777.

Schumacher, R. S. and A. J. Clark, 2014: Evaluation of ensemble configurations for the analysis and prediction of heavy-rain-producing mesoscale convective systems. Mon. Wea. Rev., 142, 4108-4138.

Grasso, L., D. T. Lindsey, K. S. Lim, A. J. Clark, D. Bikos, and S. R. Dembek, 2014: Evaluation of and suggested improvements to the WSM6 Microphysics in WRF-ARW using synthetic and observed GOES-13 imagery.  Mon. Wea. Review, 142, 3635-3650.

Vandenberg, M. A., M. C. Coniglio, and A. J. Clark, 2014: Comparison of next-day convection-allowing forecasts of storm motion on 1-km and 4-km grids. Wea. Forecasting, 29, 878-893.

Clark, A. J., R. G. Bullock, T. L. Jensen, M. Xue, and F. Kong, 2014: Application of object-based time-domain diagnostics for tracking precipitation systems in convection-allowing models. Wea. Forecasting, 29, 517-542.

Zhao, L., S-Y. Wang, J. Jin, and A. J. Clark, 2014: Weather Research and Forecasting model simulations of a rare springtime bow echo near the Great Salt Lake. Meteor. Appl. DOI: 10.1002/met.1455.

Clark, A. J., J. Gao, P. T. Marsh, T. Smith, J. S. Kain, J. Correia, M. Xue, F. Kong, 2013: Tornado pathlength forecasts from 2010 to 2011 using ensemble updraft helicity. Wea. Forecasting, 28, 387–407.

Coffer, B. E†., L. C. Maudlin†, P. G. Veals†, A. J. Clark, 2013: Dryline position errors in experimental convection-allowing NSSL-WRF model forecasts and the operational NAM. Wea. Forecasting, 28, 746–761.

Kain, J. S., M. C. Coniglio, J. Correia, A. J. Clark, P. T. Marsh, C. L. Ziegler, V. Lakshmanan, S. D. Miller, S. R. Dembek, S. J. Weiss, F. Kong, M. Xue, R. A. Sobash, A. R. Dean, I. L, Jirak, and C. J. Melick, 2013: A feasibility study for probabilistic convection initiation forecasts based on explicit numerical guidance. Bull. Amer. Meteor. Soc., 94, 1213–1225.

Schumacher, R. S., A. J. Clark, M. Xue, F. Kong, 2013: Factors Influencing the Development and Maintenance of Nocturnal Heavy-Rain-Producing Convective Systems in a Storm-Scale Ensemble. Mon. Wea. Rev., 141, 2778–2801.

Clark, A. J., J. S. Kain, P. T. Marsh, J. Correia, M. Xue, and F. Kong, 2012: Forecasting tornado path lengths using a 3-dimensional object identification algorithm applied to convection-allowing forecasts. Wea. Forecasting, 27, 1090-1113.

Lynn, B. H., Y. Yair, C. Price, G. Kelman, and A. J. Clark, 2012: Predicting cloud-to-ground and intracloud lightning in weather forecast models. Wea. Forecasting, 27, 1470-1488.

Clark, A. J., S. J. Weiss, J. S. Kain, I. L. Jirak, M. C. Coniglio, C. J. Melick, C. Siewert, R. A. Sobash, P. T. Marsh, A. R. Dean, M. Xue, F. Kong, K. W. Thomas, J. Du, D. R. Novak, F. Barhold, M. J. Bodner, J. J. Levit, C. B. Entwistle, T. L. Jensen, and J. Correia, Jr., 2012: An overview of The 2010 Hazardous Weather Testbed Experimental Forecast Program Spring Experiment. Bull. Amer. Meteor. Soc., 93, 55-74.

Marsh, P. T., J. S. Kain, V. Lakshmanan, A. J. Clark, N. M. Hitchens, and J. Hardy, 2012: A method for calibrating deterministic forecasts of rare events. Wea. Forecasting, 27, 531-538.

Clark, A. J., J. S. Kain, D. J. Stensrud, M. Xue, F. Kong, M. C. Coniglio, K. W. Thomas, Y. Wang, K. Brewster, J. Gao, X. Wang, S. J. Weiss, and J. Du, 2011: Probabilistic precipitation forecast skill as a function of ensemble size and spatial scale in a convection-allowing ensemble. Mon. Wea. Rev., 139, 1410-1418.

Clark, A. J., W. A. Gallus, M. Xue, and F. Kong, 2010: Growth of spread in convection-allowing and convection-parameterizing ensembles. Wea. Forecasting, 25, 594-612.

Clark, A. J., W. A. Gallus, M. Xue, and F. Kong, 2010: Convection-allowing and convection-parameterizing ensemble forecasts of a mesoscale convective vortex and associated severe weather environment. Wea. Forecasting, 25, 1052-1081.

Clark, A. J., W. A. Gallus, and M. L. Weisman, 2010: Neighborhood-based verification of precipitation forecasts from convection-allowing NCAR-WRF model simulations and the operational NAM. Wea. Forecasting, 25, 1495-1509.

Wang, S.-Y., and A. J. Clark, 2010: NAM model forecasts of warm season quasi-stationary frontal environments over the central US.  Wea. Forecasting, 25, 1281-1292.

Wang, S.-Y., and A. J. Clark, 2010: Quasi-decadal spectral peaks of tropical western Pacific SSTs as a precursor for tropical cyclone threat. Geophys. Res. Lett., 37, L21810, doi:10.1029/2010GL044709.

Chen, T. C., S. Y. Wang, M. C. Yen, A. J. Clark, and J. D. Tsay, 2010: Sudden surface warming/drying events caused by typhoon passages across Taiwan. J.  Appl. Meteor. Climatol., 49, 234-252.

Clark, A. J., W. A. Gallus, M. Xue, and F. Kong, 2009: A Comparison of Precipitation Forecast Skill between Small Convection-allowing and Large Convection-parameterizing ensembles. Wea. Forecasting, 24, 1121-1140.

Clark, A. J., C. J. Schaffer†, W. A. Gallus, and K. Johnson-Omara†, 2009: Climatology of storm reports relative to upper-level jet streaks.  Wea. Forecasting, 24, 1032-1051.

Chen T. C., Wang S. Y., M. C. Yen, and A. J. Clark, 2009: Impact of the intraseasonal variability of the western North Pacific large-scale circulation on tropical cyclone tracks. Wea. Forecasting, 24, 646-666.

Chen, T. C., S. Y. Wang, M. C. Yen, and A. J. Clark, 2008: Are tropical cyclones less effectively formed by easterly waves in the western North Pacific than in the North Atlantic? Mon. Wea. Rev., 136, 4527–4540.

Clark, A. J., W. A. Gallus, and T. C. Chen, 2008: Contributions of mixed physics versus perturbed initial/lateral boundary conditions to ensemble-based precipitation forecast skill. Mon. Wea. Rev., 136, 2140–2156.

Chen, T. C., S. Y. Wang, and A. J. Clark, 2008: North Atlantic hurricanes contributed by African easterly waves north and south of the African easterly jet. J. Climate, 21, 6767–6776.

Clark, A. J., W. A. Gallus, and T. C. Chen, 2007: Comparison of the diurnal precipitation cycle in convection-resolving and non-convection-resolving mesoscale models. Mon. Wea. Rev., 135, 3456–3473.