2015 Grants

Improved Understanding of Tornado Development and Risk using Models and Observations from VORTEX-SE

M. Baldwin, R. Tanamachi, D. Dawson, D. Chavas, E. Agee (Purdue Univ.); S. Frasier (Univ. Massachusetts)


Formal publications (9 additional informal publications):

Tanamachi, R. L., S. J. Frasier, J. Waldinger, A. T. LaFleur, D. D. Turner, and F. Rocadenbosch, 2019: Progress toward characterization of the atmospheric boundary layer over northern Alabama using observations by a vertically pointing, S-band profiling radar during VORTEX-Southeast. J. Atmos. Oceanic Technol., conditionally accepted.

Project completed Dec 2017

updated 2019-07-08

Resolution Dependence of Simulated Convective Storms in the Southeast United States

G. Romine, C. Schwartz, R. Sobash (NCAR); M. Coniglio (NOAA/NSSL)


  • “…able to discriminate improved forecast skill in the 1-km simulations, which emerged primarily through better predictions of cold pools associated with large mesoscale convective systems.”
  • The above work has been expanded in a NOAA/JTTI project.
  • Additional CAM surrogates that were developed and tested include 1-km AGL vertical velocity, vertical velocity at the top of the boundary layer depth, maximum vertical velocity in the PBL, updraft helicity integrated over the lowest 3 km (1 km) AGL, and vertical vorticity at the surface (1 km AGL).
  • “…finer horizontal grid spacing did not improve predictions of storm hazards, although skillful surrogate predictions for these events necessitated much lower thresholds than their central plains warm season counterparts,”
  • Hazard prediction “skill appeared to be more strongly tied to errors in the simulation of the broader mesoscale environment than to the details of simulated evolution of individual convective elements.”
  • “For the strongly forced events characteristic of the southeast U.S. during the winter season, [the investigators] found no clear benefit to using finer horizontal grid spacing, nor toward the development of additional surrogate guidance types to specifically address the high shear low CAPE environment.

Formal publications and reports (4 additional informal publications):

Schwartz, C. S. and G. S. Romine, K. R. Fossell, R. A. Sobash, and M. L. Weisman, 2017: Toward 1-km ensemble forecasts over large domains. Mon. Wea. Rev., 145, 2943-2969. (download)

Also see this: Informal report describing simulation experiments.

Project completed Dec 2018

updated 2019-07-08

Improving Understanding and Predictability of Tornadic Storms in the Southeastern U.S. Using Intensive Observations and High-Resolution Modeling

C. Weiss, E. Bruning, J. Dahl (Texas Tech Univ.); D. Dowell, C. Alexander (NOAA/ESRL)


  • Preliminary analysis, including sticknet data, of 31 Mar 2016 state line non-tornadic storm
  • Preliminary analysis, including sticknet data, of 30 Apr 2016 Priceville AL tornadic storm
  • Initial tests assimilating sticknet data into HRRRE show an impact both up- and downstream.
  • Explored the concept of the evolution of vorticity patches into concentrated vortices in supercells.
  • Explored the concept of small lightning flashes (LMA) being related to smaller-scale, more transient features, and therefore possibly more relevant to transient processes such as tornadogenesis.
  • (Several analyses carried forward to a subsequent grant.)

Formal publications and reports (none; several additional informal publications and presentations)

Project completed Nov 2017

updated 2019-07-08

Multi-disciplinary investigation of concurrent tornadoes and flash floods in the Southeastern US

R. Schumacher (Colorado State Univ.)


  • Developed a climatology of TORFF (tornado + flash flood) events.
  • Analyzed the operational warning generation during one TORFF event. “…this study revealed several ways that tornado threats can be
    collectively amplified within a forecast office and partner communities…”
  • Conducted a study of the association of heavy rainfall with mesocyclones in HSLC environments.
  • Identified long-term increasing trend in Southeast cold season tornadoes, focused in November.

Formal publications and reports (11 additional informal publications and presentations):

Nielsen, E.R. and R.S. Schumacher, 2018: Dynamical Insights into Extreme Short-Term Precipitation Associated with Supercells and Mesovortices. J. Atmos. Sci., 75,2983-3009, https://doi.org/10.1175/JAS-D-17-0385.1

Childs, S.J. and R.S. Schumacher, 2018: Cold-season Tornado Risk Communication: Case Studies from November 2016 to February 2017. Wea. Climate Soc., 10, 419–433, https://doi.org/10.1175/WCAS-D-17-0073.1

Childs, S.J., R.S. Schumacher, and J.T. Allen, 2018: Cold-Season Tornadoes: Climatological and Meteorological Insights. Wea. Forecasting, 33, 671–691,https://doi.org/10.1175/WAF-D-17-0120.1

Project completed Dec 2017

updated 2019-07-08

Addressing Interconnections between the Built and Natural Environments through Post-Event Damage Surveys

C. Godfrey (Univ. North Carolina Asheville); F. Lombardo (Rensselaer); C. Peterson (Univ. Georgia)


  • Initial analysis of debris deposition zones for the Joplin tornado
  • Preliminary analysis indicates stucture density is protective at low windspeeds, but increases damage potential at high windspeeds
  • Analysis of forest damage indicates tornadoes strengthen [weaken] when moving upslope [downslope], with little change occurring owing to ridge crossing or moving in confined valleys.
  • Treefall is more likely when trees are more isolated and have larger trunk diameter
  • Developed simulations combining tornado windfield, trees, and structures to assess the interactions
  • Developed EF-scale indicators based on tree damage in forests

Formal publications and reports (4 additional informal publications and presentations):

Cannon, J. B., J. Hepinstall-Cymerman, C. M. Godfrey, and C. J. Peterson, 2016: Landscape-scale patterns of forest tornado damage in mountainous terrain. Landscape Ecol., 31, 2097–2114,

Godfrey, C. M., and C. J. Peterson, 2017: Estimating enhanced Fujita scale levels based on forest damage severity. Wea. Forecasting, 32, 243–252, https://doi.org/10.1175/WAF-D-16-0104.1

Zenoble, M. D., and C. J. Peterson, 2017: Remotely visible width and discontinuity of 50 tornado damage paths through forested landscapes. Electronic J. Severe Storms Meteor.,12 (1), 1–21. (download)

Roueche, D. B., F. T. Lombardo, and D. O. Prevatt, 2017: Empirical Approach to Evaluating the Tornado Fragility of Residential Structures. J. Struct. Engr., 143(9), https://doi.org/10.1061/(ASCE)ST.1943-541X.0001854

Project completed Jan 2017

updated 2019-07-08

Tornado warning response in the Southeast: Advancing knowledge for action in Tennessee

K. Ellis, L. Reyes Mason (Univ. Tennessee)

Possible outcomes:

  • Examine individual perceived tornado risk versus climatological risk
  • Examine multilevel predictors of tornado warning access, understanding, and response, for daytime versus nocturnal warnin
  • Investigate why “…individuals from vulnerable groups have inadequate warning access, less understanding, and/or less likelihood of responding to tornado warnings, including both daytime and nocturnal warnings”
  • Develop and assess the effectiveness of regional workshops for targeted groups

Formal publications and reports (12 additional informal publications and presentations):

Ellis, K.N., Mason, L.R., Gassert, K.N. et al. Int J Biometeorol (2018) 62: 1557. https://doi.org/10.1007/s00484-018-1547-x

Walters, J. E., L. R. Mason, and K. N. Ellis, 2019: Examining patterns of intended response to tornado warnings among residents of Tennessee, United States, through a latent class analysis approach. Intl. J. Disaster Risk Reduction, 34, 375-386, https://doi.org/10.1016/j.ijdrr.2018.12.007

Mason, L.R., K.N. Ellis, B. Winchester, and S. Schexnayder, 2018: Tornado Warnings at Night: Who Gets the Message?. Wea. Climate Soc., 10, 561–568,https://doi.org/10.1175/WCAS-D-17-0114.1

Ellis, K.N., Mason, L.R., Gassert, K.N. et al., 2018: Public perception of climatological tornado risk in Tennessee, USA. Int J Biometeorol (2018) 62: 1557. https://doi.org/10.1007/s00484-018-1547-x

Ellis, K. N., L. R. Mason, and K. N. Gassert: Public perception of tornado characteristics and protection from land-surface features: Public perceptions and the role of local geography. PLoS ONE, in revision.

Project in progress under no-cost extension November 2019

updated 2019-11-12

Complacency and False Alarms in Tornado Affected Communities

M. Egnoto, B. Liu (START / Univ. Maryland)


  • According to the study data, false alarms do not cause complacency in Southeast US residents
  • Local broadcast meteorologists are a primary source of tornado information
  • Mobile home residents have less access to tornado information than fixed home residents
  • Information seeking and sharing delays protective action
  • some emotional coping and religious coping can drive productive protective action decision making in response to tornado watches and warnings.

Formal publications and reports:

Grant final report (214 pp; PDF) For VORTEX-SE Community Forum use; please do not disseminate this report without permission of the authors.

Rhys Lim, J, Fisher Liu, B, Egnoto, M, Roberts, H. Individuals’ religiosity and emotional coping in response to disasters. J Contingencies and Crisis Management. 2019; 00: 1– 15. https://doi.org/10.1111/1468-5973.12263

Lim, J.R., B.F. Liu, and M. Egnoto, 2019: Cry Wolf Effect? Evaluating the Impact of False Alarms on Public Responses to Tornado Alerts in the Southeastern United States. Wea. Climate Soc., 11, 549–563, https://doi.org/10.1175/WCAS-D-18-0080.1 

Liu, B.F., M. Egnoto, and J.R. Lim, 2019: How Mobile Home Residents Understand and Respond to Tornado Warnings. Wea. Climate Soc., 11, 521–534, https://doi.org/10.1175/WCAS-D-17-0080.1 

Project completed June 2017

updated 2019-07-08

VORTEX-SE: Polarimetric Radar-based Field Campaign Activities and Storm Scale Studies

L. Carey (Univ. Alabama Huntsville)


  • Initial analyses indicate that “FFD and RFD enhancements closely precede lightning dive occurrence”
  • Initial analyses indicate that “Nontornadic supercells experienced larger updraft and rear-flank downdraft (RFD) magnitudes compared to the tornadic supercell”
  • “Although the effects of melting cannot be ruled out, possible larger evaporation rates occurring in the RFD of non-tornadic supercells, depleting smaller drops, leading to larger ZDR-inferred drops in the non-tornadic hook echo and helping to explain the stronger RFDs.”

Formal publications and reports (None; 4 additional informal publications and presentations)

Project completed January 2017

updated 2019-07-08

Understanding the Variability and Predictability of Southeastern Severe Storm Environments using Mobile Soundings during VORTEX-SE

M. Brown (Mississippi State); M. Parker (North Carolina State Univ.); T. Murphy (Univ. Louisiana Monroe)


  • Obtained 238 soundings in VORTEX-SE 2016 spring campaign
  • Initial simulation work completed; continued in a 2016 VORTEX-SE grant (see below).

Formal publications and reports (4 additional informal publications and presentations)

Sherburn, K.D. and M.D. Parker, 2019: The Development of Severe Vortices within Simulated High-Shear, Low-CAPE Convection. Mon. Wea. Rev., 147, 2189–2216, https://doi.org/10.1175/MWR-D-18-0246.1 

Project completed December 2017

updated 2019-07-08

Infrastructure development, initial data analysis, and field campaign activities

K. Knupp (Univ. Alabama Huntsville)


  • Constructed the Rapidly Deployable Atmospheric Profiling System (RaDAPS).
  • Preliminary investigation of the association of tornado occurrence with the Sand Mountain plateau.
  • Preliminary quantification of relative numbers of tornadoes associated with supercells and QLCS in northern Alabama (50%/50%)
  • Collected field observations in 2016 VORTEX-SE field campaign.

Formal publications and reports

Coleman, T. A., A. W. Lyza, K. R. Knupp, K. Laws, and W. Wyatt, 2018: A significant tornado in a heterogeneous environment during VORTEX-SE. Electronic J. Severe Storms Meteor., 13 (2), 1–25. (download)

Project completed June 2016

updated 2019-07-08

Collaborative Research: Understanding the Current Flow of Weather Information and Associated Uncertainty, and Their Affect on Emergency Managers and General Publics

D. LaDue, J. Friedman (Univ. Oklahoma); L. Myers (U. Alabama)


  • Found that “forecasters believe that there is a higher prevalence of high shear, low CAPE, tornado-producing event that are significantly more difficult to forecast and communicate than more (in their words) ‘traditional supercell-related events.’”
  • “Forecasters described the special challenges that they faced in having to account for historically-poor model guidance associated with coastal/marine-initiated atmospheric conditions moving into the area from the Gulf of Mexico.”
  • “…forecasters noted that they felt like they were constantly on watch for weather with severe convective potential, which could, in turn, lead them to have difficulty prioritizing or focusing on specific events.”
  • “Probably most troubling for the forecasters was the difficulty of being able to communicate to stakeholders/EMs the timing of the forecasted event.”
  • Explored the use of social media in the KHUN forecast office.
  • “observations should give pause to future social scientists who expect to learn about ‘forecasting’ from post-event interviews that are often conducted days, weeks, months, or even years after an event.”
  • Identified perception issues related to severe thunderstorm warnings; warnings for short-lived tornadoes; threat perception related to local perception of “tornado alleys”; numerous others.

Formal publications and reports (None; 11 additional informal publications and presentations)

(See Community Forum blog post from Laura Myers related to this work. [ENR add link to blog])

Project completed October 2016

updated 2019-07-08

Multi-year WSR-88D radar climatology of tornadic storms in the SE United States

T. Smith, K. Ortega (NOAA/NSSL)


  • Discovered major challenges in processing 88D for climatological work.
  • Updated approach is underway and opportunities for collaborative research will commence ~late 2020.

Formal publications and reports: None.

Project in progress under no-cost extension July 2019

updated 2019-07-08

Storm-scale Ensemble Forecasts of Cool Season Severe Weather during VORTEX-Southeast

P. Skinner (NOAA/NSSL)


  • Forecast accuracy is degraded in cases where supercells have a small areal extent, are in close proximity to additional convection, or exhibit rapid temporal evolution; all of which are common occurrences for cool-season thunderstorms in the southeastern U.S. It is hypothesized that this degradation may be partially mitigated through increased spatial resolution of both observations and forecasts.
  • Additionally, it is expected that use of more sophisticated microphysical parameterization will mitigate destructive interactions of storm cold pools in close proximity.
  • Storm-scale forecast accuracy appears to be highly dependent on accurate prediction of the near-storm mesoscale environment. Similarly, small spatial errors in sharp mesoscale gradients, such as frontal boundaries, can result in large errors in the near-storm environment and poor storm-scale forecasts.

Formal publications and reports

Skinner, P. S., D. M. Wheatley, K. H. Knopfmeier, A. E. Reinhart, J. J. Choate, T. A. Jones, G. J. Creager, D. C. Dowell, C. R. Alexander, T. T. Ladwig, L. J. Wicker, P. L. Heinselman, P. Minnis, and R. Palikonda, 2018:  Object-based verification of a prototype Warn-on-Forecast system.  Wea. Forecasting, 33, 1225–1250

Project completed July 2016

updated 2019-07-15

Boundary layer observations in VORTEX-Southeast



  • Deployed Doppler lidar and two 10-m instrumented towers to northern AL and collected observations in the Spring 2016 campaign. Also obtained 65 special soundings.
  • Used COMMAS to perform idealized studies of nonclassical mesoscale circulations and associated convection initiation.
  • Used COMMAS to study an episode of rapid destabilization associated with convection initiation.

Formal publications and reports (one additional informal report or presentation)

Lee, T.R., M. Buban, D.D. Turner, T.P. Meyers, and C.B. Baker, 2019: Evaluation of the High-Resolution Rapid Refresh (HRRR) Model Using Near-Surface Meteorological and Flux Observations from Northern Alabama. Wea. Forecasting, 34, 635–663, https://doi.org/10.1175/WAF-D-18-0184.1 (VORTEX-SE supported the instrumentation of the Belle Mina and Cullman sites used in this study.)

Project completed July 2016

updated 2019-07-15

Demonstration of a Cycled High ­Resolution Rapid Refresh Capability During a Cool­ Season Tornado Outbreak

J. Whitaker, S. Benjamin (NOAA/ESRL)


  • “…developed a prototype cycled, convective-allowing ensemble analysis and prediction system — a High-Resolution Rapid Refresh Ensemble (HRRRE).”
  • “…applied the prototype HRRRE to the high-CAPE, strong-shear 27 April 2011 tornado outbreak case first and then to cool-season tornado cases: 23 December 2015 and 31 March
  • “The qualitative forecast skill of individual HRRREmembers was at least comparable to that of the deterministic HRRR.”

Formal publications and reports (None reported)

The Final Project Report is a fairly comprehensive summary of this project.

Project completed July 2017

updated 2019-07-15

Using the HWRF Model to Assess Tornado Risk in Landfalling Tropical Cyclones

F. Marks (NOAA/AOML)


  • Conducted an HWRF simulation of landfalling Hurricane Isaac (2012)
  • Identified regions of enhanced Signficant Tornado Parameter in rainbands, especially when interacting with the coast.
  • Identified enhanced low-level vertical vorticity features at 2 km resolution perhaps indicative of shallow potentially tornadic supercells.

Formal publications and reports (None reported)

The Final Project Report is a fairly comprehensive summary of this project.

Project completed December 2015

updated 2019-07-15