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Lightning & Tornadoes

It's been noted that updrafts briefly weaken immediately before and during a tornado. Lightning is a result of charge seperation, which is a partial function of updraft velocity. So, from that, I'd think that lightning activity would actually decrease a tad before and during a tornado. On the other hand, the temporarily weakened updraft may decrease the charge seperation distance, and allow for more electric field breakdowns. Of course, this ignores the potential impact of debris.

Fortune was with the researchers that day and the F4 moved almost exactly between two of the turtles. To the researchers surprise, they saw the electric field dipped, and no lightning as recorded.

Hunyady said that lack of electrical activity may be due to lofted debris reducing the electric field, or possibly to increased conductivity inside the tornado itself.
More lightning news from inside hurricanes and tornadoes (NASA)

Anomalous Anton Seimon. 1993: Anomalous Cloud-to-Ground Lightning in an F5-Tornado-Producing Supercell Thunderstorm on 28 August 1990. Bulletin of the American Meteorological Society: Vol. 74, No. 2, pp. 189–203.

Characteristics of Cloud-to-Ground Lightning Associated with Violent Tornadoes -- Perez, Antony H., Wicker, Louis J., Orville, Richard E.

Donald R. MacGorman and Kurt E. Nielsen. 1991: Cloud-to-Ground Lightning in a Tornadic Storm on 8 May 1986. Monthly Weather Review: Vol. 119, No. 7, pp. 1557–1574.

Antony H. Perez, Louis J. Wicker and Richard E. Orville. 1997: Characteristics of Cloud-to-Ground Lightning Associated with Violent Tornadoes. Weather and Forecasting: Vol. 12, No. 3, pp. 428–437.

Eugene W. McCaul Jr., Dennis E. Buechler, Steven J. Goodman and Michael Cammarata. 2004: Doppler Radar and Lightning Network Observations of a Severe Outbreak of Tropical Cyclone Tornadoes. Monthly Weather Review: Vol. 132, No. 7, pp. 1747–1763.

Donald R. MacGorman, Donald W. Burgess, Vladislav Mazur, W. David Rust, William L. Taylor and Brenda C. Johnson. 1989: Lightning Rates Relative to Tornadic Storm Evolution on 22 May 1981. Journal of the Atmospheric Sciences: Vol. 46, No. 2, pp. 221–251.

Howard B. Bluestein and Donald R. MacGorman. 1998: Evolution of Cloud-to-Ground Lightning Characteristics and Storm Structure in the Spearman, Texas, Tornadic Supercells of 31 May 1990. Monthly Weather Review: Vol. 126, No. 6, pp. 1451–1467.

Eugene W. McCaul Jr., Dennis E. Buechler, Stephen Hodanish and Steven J. Goodman. 2002: The Almena, Kansas, Tornadic Storm of 3 June 1999: A Long-Lived Supercell with Very Little Cloud-to-Ground Lightning. Monthly Weather Review: Vol. 130, No. 2, pp. 407–415.

B.N. Turman and R.J. Tettelbach. 1980: Synoptic-Scale Satellite Lightning Observations in Conjunction with Tornadoes. Monthly Weather Review: Vol. 108, No. 11, pp. 1878–1882.

Lawrence D. Carey, Steven A. Rutledge and Walter A. Petersen. 2003: The Relationship between Severe Storm Reports and Cloud-to-Ground Lightning Polarity in the Contiguous United States from 1989 to 1998. Monthly Weather Review: Vol. 131, No. 7, pp. 1211–1228.

Donald R. Macgorman and Donald W. Burgess. 1994: Positive Cloud-to-Ground Lightning in Tornadic Storms and Hailstorms. Monthly Weather Review: Vol. 122, No. 8, pp. 1671–1697.

Ross Gunn. 1956: ELECTRIC FIELD INTENSITY AT THE GROUND UNDER ACTIVE THUNDERSTORMS AND TORNADOES. Journal of the Atmospheric Sciences: Vol. 13, No. 3, pp. 269–273.

**** I realize those don't do you much unless you have access to AMS jounals online. But, you may, so I posted them anyway.
Upon renewing my AMS membership, this was part of a note to student members:

Of related interest is the fact that as of 1 January 2006, AMS is greatly expanding that portion of its electronic journal content available on a free-and-open basis. On that day, anyone and everyone will have free and open access to all AMS journal articles published through 31 December 2000 in all available forms (HTML and PDF). This will be a moving 5-year “wallâ€￾; as of 1 January 2007, total free access will be extended to articles published through 31December 2001, and so on. AMS is pleased to join an increasing number of scientific societies offering or expanding open access to peer-reviewed research.

Jeff writes:

I realize those don't do you much unless you have access to AMS jounals online. But, you may, so I posted them anyway.

No, but getting access would be cool. How do I go about it? AMS is American Meteorological Service, yes?