How are lightning and thunderstorm intensity linked?

Question

I have lightning data that contains individual strikes and their location, time, polarity, amplitude and type (cloud-to-ground, intracloud). I am trying to develop some metrics that will help me assess if a thunderstorm is intense or not. By intense, I mean if it has the potential to generate heavy rain, large hail and strong winds. I plan on using radar reflectivity as my best guess of storm intensity and building a statistical model between the two datasets.

By browsing through the litterature, it seems that a sharp increase in positive cloud-to-ground lightning frequency is a sign of storm intensification to come. I was wondering if there was anything else that I could work with. Is amplitude useful in any way? Is the ratio of IC to CG lightning relevant? Is there another metric I could develop?

Thanks!

Answer 1

Is the ratio of IC to CG lightning relevant?

Yes. Primarily, severe storms tend to have very few cloud-to-ground (CG) strikes. Thus, the ratio of IC:CG is likely going to be very high.^{1 2} However, some severe storms do produce a significant amount of positive CG strikes. They would still have a high IC:CG ratio, but they would distinguish themselves by having more positive CG strikes. However, both of these types -- low-CG and some-positive-CG -- are potentially severe.²

It is important to note that the amount of CG strikes can be dependent both on where in the lifecycle a storm is, and the physical location of a storm (CG characteristics appear to be region-dependent). In tornadic supercells, the total amount of lightning seems to decrease during tornadogenesis, and the CG rate appears to increase after the tornadic stage of that supercell ends.³

There doesn't appear to be any existing literature on amplitude as a measure of severity. Perhaps, through this work, you might be able to identify whether this is an area which should be studied further.

References

¹ 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. J. Atmos. Sci., 46, 221–251, doi: 10.1175/1520-0469(1989)046<0221:LRRTTS>2.0.CO;2.

² Timothy J. Lang and Steven A. Rutledge, 2002: Relationships between Convective Storm Kinematics, Precipitation, and Lightning. Mon. Wea. Rev., 130, 2492–2506, doi: 10.1175/1520-0493(2002)130<2492:RBCSKP>2.0.CO;2.

³ Scott M. Steiger, Richard E. Orville, and Lawrence D. Carey, 2007: Total Lightning Signatures of Thunderstorm Intensity over North Texas. Part I: Supercells. Mon. Wea. Rev., 135, 3281–3302, doi: 10.1175/MWR3472.1.

Further Reading

• 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. Mon. Wea. Rev., 131, 1211–1228, doi: 10.1175/1520-0493(2003)131<1211:TRBSSR>2.0.CO;2.

• Yeung, Linus HY, E. S. T. Lai, and S. K. S. Chiu. "Lightning Initiation and Intensity Nowcasting Based on Isothermal Radar Reflectivity-A Conceptual Model." The 33rd International Conference on Radar Meteorology. 2007.

• C. Emersic, P. L. Heinselman, D. R. MacGorman, and E. C. Bruning, 2011: Lightning Activity in a Hail-Producing Storm Observed with Phased-Array Radar. Mon. Wea. Rev., 139, 1809–1825, doi: 10.1175/2010MWR3574.1.