In Situ Video Observations and Analysis of the 16 June 2014 Pilger, Nebraska EF4 west Tornado


  • Lanny Dean PACRITEX
  • David Moran DTN, PACRITEX
  • Randy Hicks PACRITEX



In-situ observations, In-situ probe, Higher-order multiple vortices, Sub-vortices, Tornadoes, Multiple vortex tornado, Tornado video observations, Streamwise Vorticity, Tornadogenesis


An unusual tornado event involving two large and violent EF4 tornadoes occurring simultaneously impacted the Pilger, NE area on 16 June 2014, resulting in two deaths. A privately funded scientific field campaign successfully obtained in-situ video observations inside the western-most tornado prior to it striking the town of Pilger. The results resolve fine details of the tornado core wind field, which are presented and discussed, including several important or unique observations not previously documented within existing in-situ tornado video research. These include documentation of many sub-vortices (as many as nine concurrently at one point) evolving and dissolving on the order of seconds or fractions of seconds while rotating about a concentrical axis. Visual observation of a single but separate vortex that was likely a sub-vortex on the outside rim of the tornado core and observations confirm tornadic damage well outside the visible parent tornado vortex. This study also adds to the small number of tornado cases documented using in-situ observations as a reference for further research.

Author Biographies

Lanny Dean, PACRITEX

Lanny Dean: PACRITEX Founder - Applied Scientific and Instrumentation, In-situ Tornado Research, Field group Leader, Instrumentation of electronic of development and design.  

David Moran, DTN, PACRITEX

My name is David Moran. I attend the University of Oklahoma and earned a Bachelor of Science in Meteorology and a Bachelor of Arts in Mathematics. After college, I started working as a consulting meteorologist for Weather Decision Technologies. I am now a meteorologist with DTN.

In 2017, I earned my Certified Consulting Meteorologist (CCM) certification (#730) from the American Meteorological Society. As of June 2019, I am one of 242 active CCMs. Shortly after receiving my CCM, I was elected to a four year term to the Board of Certified Consulting Meteorologists beginning in 2018. In March 2018, I was selected to be chair of a subcommittee on the CCM Exam Overhaul Committee. 


Agee, E. M., Snow, J. T., & Clare, P. R., 1976: Multiple Vortex Features in the Tornado Cyclone and the Occurrence of Tornado Families. Monthly Weather Review, 104(5), 552-563.

Blair, S. F., D. R. Deroche, and A. E. Pietrycha., 2008: In situ observations of the 21 April 2007 Tulia, Texas tornado. Electronic J. Severe Storms Meteor., 3 (3), 1-27.

Bluestein, H. B., Thiem, K. J., Snyder, J. C., & Houser, J. B., 2018: The Multiple-Vortex Structure of the El Reno, Oklahoma, Tornado on 31 May 2013. Monthly Weather Review, 146(8), 2483-2502.

——, Snyder, J. C., & Houser, J. B., 2015: A Multiscale Overview of the El Reno, Oklahoma, Tornadic Supercell of 31 May 2013. Weather and Forecasting, 30(3), 525-552.

Davies, J. M., Doswell, C. A., III, Burgess, D. W., & Weaver, J. F., 1994: Some Noteworthy Aspects of the Hesston, Kansas, Tornado Family of 13 March 1990. Bulletin of the American Meteorological Society, 75(6), 1007-1018.

Edwards, R., 2014: Characteristics of supercellular satellite tornadoes. Proc. 27th Conf. on Severe Local Storms, Madison, WI, Amer. Meteor. Soc., 17.5.

Fiedler, B. H., 1993: Numerical simulations of axisymmetric tornadogenesis in forced convection. The Tornado: Its Structure, Dynamics, Predication, and Hazard. Geophys. Monogr., Vol. 79, Amer. Geophys. Union, 41–48.

Fujita, T. T., D. L. Bradbury, and C. F. Van Thullenar., 1970: Palm Sunday tornadoes of April 11, 1965. Mon. Wea. Rev., 98, 29–69.

Holle, R. L., 1982: Photogrammetry of thunderstorms. Thunderstorms: A Social and Technological Documentary, E. Kessler, Ed., University of Oklahoma Press, 77–98.

Karstens, C. D., Samaras, T. M., A. Laubach, B. D. Lee, C. A. Finley, W. A. Gallus, F. L. Haan., 2008: TWISTEX 2008: In situ and mobile mesonet observations of tornadoes. 24th Conf. on Severe Local Storms, Savannah, GA, Amer. Meteor. Soc., P3.11.

——, ——, and Lee, B. D., Gallus, W. A., Jr., & Finley, C. A., 2010: Near-Ground Pressure and Wind Measurements in Tornadoes. Monthly Weather Review, 138(7), 2570-2588.

Kosiba, K. A., and Wurman, J., 2016: The TWIRL Tornado Winds from In-situ and Radars at Low-level Project. 28th Conf. on Severe Local Storms, Portland, OR, Amer. Meteor. Soc., 15.3.

——, ——, 2013: The Three-Dimensional Structure and Evolution of a Tornado Boundary Layer. Weather and Forecasting, 28(6), 1552-1561.

——, ——, 2010: The Three-Dimensional Axisymmetric Wind Field Structure of the Spencer, South Dakota, 1998 Tornado. Journal of the Atmospheric Sciences, 67(9), 3074-3083.

Lee, J.J., Samaras, T. M., C. Young., 2004: Pressure measurements at the ground in an F-4 tornado. 22nd Conf. on Severe Local Storms, Stowe, VT, Amer. Meteor. Soc., 15.3.

Lee, B. D., Finley, C. A., & Samaras, T. M., 2011: Surface Analysis near and within the Tipton, Kansas, Tornado on 29 May 2008. Monthly Weather Review, 139(2), 370-386.

Lewellen, W. S., Lewellen, D. C., & Sykes, R. I., 1997: Large-Eddy Simulation of a Tornado’s Interaction with the Surface. Journal of the Atmospheric Sciences, 54(5), 581-605.

Lewellen, D. C., Lewellen, W. S., & Xia, J., 2000: The Influence of a Local Swirl Ratio on Tornado Intensification near the Surface. Journal of the Atmospheric Sciences, 57(4), 527-544.

Orf, L., Wilhelmson, R., Lee, B., Finley, C., & Houston, A., 2017: Evolution of a Long-Track Violent Tornado within a Simulated Supercell. Bulletin of the American Meteorological Society, 98(1), 45-68.

——, Dixon A., & Halbert, K. T., 2018: The Role of the Streamwise Vorticity Current in Tornado Genesis and Maintenance. 29th Conf. on Severe Local Storms, Stowe, VT, Amer. Meteor. Soc., 1.4.

Potts, S. L., and Agee E. M., 2002: Three scales for multiple vortices. Preprints, 21st Conf. on Severe Local Storms, San Antonio, TX, Amer. Meteor. Soc., 527–530.

Rasmussen, E. N., Straka, J. M., Davies-Jones, R., Doswell, C. A., III, Carr, F. H., Eilts, M. D., & MacGorman, D. R., 1994: Verification of the Origins of Rotation in Tornadoes Experiment: VORTEX. Bulletin of the American Meteorological Society, 75(6), 995-1006.

——, Davies-Jones, R., & Holle, R. L. 2003: Terrestrial Photogrammetry of Weather Images Acquired in Uncontrolled Circumstances, Journal of Atmospheric and Oceanic Technology, 20(12), 1790-1803.

Rotunno, R., 1977: Numerical simulation of a laboratory vortex. J. Atmos. Sci., 34, 1942–1956.

——, 1979: A study in tornado-like vortex dynamics. J. Atmos. Sci., 36, 140–155.

——, 1984: An Investigation of a Three-Dimensional Asymmetric Vortex. Journal of Atmospheric Sciences, 41(2), 283-298.0.

Samaras, T. M., 2006: Dynamic Measurements of the Lowest 10 meters of Tornadoes. 23rd Conf. on Severe Local Storms, St. Louis, MO, Amer. Meteor. Soc., 14.3.

——, Lee, J. J., 2003: Pressure measurements within a large tornado. Preprints, Eighth Symposium on Integrated Observing and Assimilation Systems for Atmosphere, Oceans, and Land Surface, 84th AMS Annual Meeting, Seattle, WA, Amer. Meteor. Soc., 4.9, 1-9.

Seimon, A., Allen, J. T., Seimon, T. A., Talbot, S. J., & Hoadley, D. K., 2016: Crowdsourcing the El Reno 2013 Tornado: A New Approach for Collation and Display of Storm Chaser Imagery for Scientific Applications. Bulletin of the American Meteorological Society, 97(11), 2069-2084.

Trapp, R. J., 2000: A Clarification of Vortex Breakdown and Tornadogenesis. Monthly Weather Review, 128(3), 888-895.

Wakimoto, R. M., Atkins, N. T., Butler, K. M., Bluestein, H. B., Thiem, K., Snyder, J., & Houser, J. (2015). Photogrammetric Analysis of the 2013 El Reno Tornado Combined with Mobile X-Band Polarimetric Radar Data, Monthly Weather Review, 143(7), 2657-2683.

Ward, N. B., 1972: The Exploration of Certain Features of Tornado Dynamics Using a Laboratory Model, Journal of Atmospheric Sciences, 29(6), 1194-1204.

Wurman, J., Kosiba, K., Robinson, P., & Marshall, T., 2014: The Role of Multiple Vortex Tornado Structure in Causing Storm Researcher Fatalities. Bulletin of the American Meteorological Society, 95(1), 31-45.

——, ——, ——, 2013: In Situ, Doppler Radar, and Video Observations of the Interior Structure of a Tornado and the Wind–Damage Relationship. Bulletin of the American Meteorological Society, 94(6), 835-846.

——, ——, 2013: Finescale Radar Observations of Tornado and Mesocyclone Structures. Weather and Forecasting, 28(5), 1157-1174.