On the evening of 26 May 2026, Levi Riggins recorded multiple upward lightning flashes from a tall tower near Bertram, Texas. This tower located at coordinates 30.726194, -97.990389 is 1,960 ft tall. Between 03:54:51 UTC and 06:24:15 UTC, 2026-05-27 (2254 – 0124 local), he witnessed 18 lightning flashes attached to the tower from 17 km away. He recorded 13 upward flashes with a Nikon Z6, 50mm lens (flashes 1-9), 20mm lens (flashes 10-13), f/2, ISO 1600, 1/125 exposure recording at 120 images per second.
I conducted a video analysis seeking to identify visual behavior characteristics and correlated the optical observations with lightning pulse data from Earth Networks, Inc., an AEM company which graciously provided the data for this analysis.
What follows is a summary of each of flashes recorded showing the recorded video along with a plot of the Earth Networks lightning location data with the tower location in the center of the north up plot and the camera location shown with a + sign to the southeast. The legend provides the classification of the events recorded by Earth Networks. The timecode shown in the video is approximately 0.4 seconds behind actual time.
I would like to thank Levi for reaching out and providing these videos and for allowing me to analyze these impressive events.
Upward Flash #1, 04:13:27. Upward positive leader triggered by negative leader activity passing over the tower following a +CG return stroke to the south-southeast. The upward positive leader exhibited low branching (less than 1/3rd of the distance to cloud base) as well as cloud base branching in which the branched leader transitioned to horizontal propagation upon reaching cloud base and increased branching significantly. Many newly developed horizontal branches decayed and developed recoil leaders. There were no subsequent recoil leaders that extended back to the main channel or tower. Triggering flash: +CG, Triggering component: negative leaders, Subsequent m-components or return strokes detected at the tower: none
Upward Flash #2, 04:15:09 UTC. Upward positive leader triggered by negative leader activity passing over the tower following a +CG return stroke to the east. The upward positive leader exhibited no branching until cloud base at which point the leader transitioned to horizontal propagation and increased branching significantly. Many newly developed horizontal branches decayed and developed recoil leaders. One horizontal branch produced a recoil leader and the negative end deviated from the original branch channel path and propagated upward into the cloud toward the apparently horizontally extensive positive charge layer that negative leaders propagated toward and through previously. This branched upward positive leader section became separate from the lower portion of the upward flash after the main upward leader channel decayed. Continued positive leader growth and recoil leader activity on the isolated upper portion of the upward leader network constituted a secondary hybrid intracloud flash. Prior to this transition, there were was one subsequent recoil leader that extended back to the tower resulting in an estimated -12.7 kA -CG return stroke. Triggering flash: +CG, Triggering component: negative leaders, Subsequent m-components or return strokes detected at the tower: 1 -CG
Upward Flash #3, 04:18:33 UTC. Upward positive leader triggered by negative leader activity passing over the tower following a +CG return stroke to the north-northeast. The upward positive leader exhibited no branching prior to cloud base, but was angled toward the east/northeast. Upon reaching cloud base the upward leader branched significantly. Many newly developed horizontal branches decayed and developed recoil leaders some of which extended back to the tower resulting in subsequent return strokes. Triggering flash: +CG, Triggering component: negative leaders, Subsequent m-components or return strokes at the tower: 5 (4 -CG, 1 -IC)
Flash #4, 04:35:10 UTC. Upward positive leader triggered by a +CG return stroke to the west-southwest. The upward positive leader exhibited low branching and angled toward the west during growth. Upon reaching cloud base the upward leader transitioned to horizontal propagation and branched significantly. Many newly developed horizontal branches decayed and developed recoil leaders some of which extended back to the main channel or tower resulting in subsequent m-components and return strokes. Triggering flash: +CG, Triggering component: +CG return stroke, Subsequent m-components or return strokes detected at the tower: 1 (1 -CG)
Flash #5, 04:38:22 UTC. Upward positive leader triggered by negative leader activity passing over the tower following a +CG return stroke to the east. The upward positive leader exhibited mid-level branching prior to cloud base. Upon reaching cloud base the upward leader transitioned to horizontal propagation and branched significantly. Many horizontal branches decayed and developed recoil leaders some of which extended back to the main channel and tower resulting in subsequent m-components and return strokes. Triggering flash: +CG, Triggering component: negative leaders, Subsequent m-components or return strokes detected at the tower: 4 (3 -CG, 1 -IC)
Flash #6, 04:42:03 UTC. Upward positive leader triggered by negative leader activity passing over the tower following a +CG return stroke to the east. The upward positive leader exhibited mid-level branching prior to cloud base. Upon reaching cloud base the upward leader transitioned to horizontal propagation and branched significantly. Many horizontal branches decayed and developed recoil leaders some of which extended back to the main channel and tower resulting in subsequent m-components and return strokes. Triggering flash: +CG, Triggering component: negative leaders, Subsequent m-components or return strokes detected at the tower: 10 (10 -CG)
Flash #7, 04:49:54 UTC. Upward positive leader triggered by negative leader activity passing over the tower following a +CG return stroke to the east-northeast. The upward positive leader exhibited low-level branching prior to cloud base. Upon reaching cloud base the upward leader transitioned to horizontal propagation and branched significantly. Some horizontal branches decayed and developed recoil leaders some of which extended back to the main channel and tower resulting in subsequent m-components and return strokes. After upward leader development, downward positive leaders developed from cloud base to the right (east) of the upward leader. These likely developed from decayed negative incloud leaders associated with the triggering flash. A +CG return stroke also occurred to the left (west) of the field of view after upward leader development. This was likely due to additional downward positive leader development from decayed negative leaders formed during the triggering flash. Triggering flash: +CG, Triggering component: negative leaders, Subsequent m-components or return strokes detected at the tower: 1 (1 -IC)
Flash #8, 05:03:55 UTC. A weakly luminous upward positive leader triggered by negative leader activity passing over the tower following a +CG return stroke to the south-southwest. The upward leader exhibited low-level branching and decayed as the leader approached cloud base. Positive leaders and recoil leader activity associated with the triggering flash were visible in the foreground during the development of the upward leader. This positive leader activity may have acted to quench the continued development of the upward positive leader. Triggering component: negative leaders, Subsequent m-components or return strokes detected at the tower: none
Flash #9, 05:07:48 UTC. An upward positive leader was triggered by negative leaders as they passed over the tower prior to a +CG return stroke to the south-southwest. The initial development of the upward positive leader prior to the return stroke was weakly luminous and exhibited low-level branching. However, immediately following the return stroke the upward positive leader brightened significantly and exhibited numerous highly energetic recoil leader connections with the main luminous channel and with the tower as the main channel frequently decayed completely during upward propagation toward cloud base. Upon reaching cloud base, one remaining luminous branch transitioned to horizontal propagation and developed additional branches and recoil leaders. A very high number of impulsive events were detected by the Earth Networks system (29 total) correlated with the highly luminous recoil leader connections. Downward positive leader activity associated with the triggering flash was visible in the foreground during upward positive leader development. Triggering flash: +CG, Triggering component: negative leaders prior to a +CG return stroke, Subsequent m-components or return strokes detected at the tower: 29 (12 -CG, 17 -IC)
Flash #10, 05:41:20 UTC. An upward positive leader was triggered from the tower by incloud negative leaders as they passed over/near the tower following a +CG return stroke to the east. The upward positive leader exhibited low-level branching and decayed upon reaching cloud base. Multiple recoil leaders formed on decayed upward positive branches as the upward leader developed, however, no impulsive events at the tower were recorded. There was extensive incloud triggering flash activity that lasted well beyond the decay of the upward positive leader and some downward positive leaders were visible during the flash. Triggering flash: +CG, Triggering component: negative leaders, Subsequent m-components or return strokes detected at the tower: none.
Flash #11, 05:45:46 UTC. A weakly luminous upward positive leader was triggered by incloud negative leaders following a +CG return stroke to the east-southeast. The upward positive leader exhibited low-level branching and decayed before reaching cloud base likely due to the development of downward positive leaders nearby which quenched the upward positive leader growth. These downward positive leaders clearly developed from the triggering negative leader activity that traveled west near the tower and caused a +CG return stroke 4.1 km northwest of the tower. The Earth Networks data indicated an estimated 42 kA peak current +IC correlated with the visible CG. There was extensive incloud triggering flash activity that lasted well beyond the decay of the upward positive leader. Triggering flash: +CG, Triggering component: negative leaders, Subsequent m-components or return strokes detected at the tower: none.
Flash #12, 06:16:49 UTC. Negative leaders associated with the hybrid CG-IC flash triggered an upward positive leader from the tower. A -CG flash with visible -CG return strokes and correlated negative lightning location events occurred to the east-northeast. After a -CG return stroke channel decay, incloud luminosity pulses characteristic of recoil leader activity in the upper positive leader portion of the -CG flash developed. Intense incloud horizontal negative leader growth followed one of these luminosity pulses as the negative end of the recoil leader likely propagated toward and into a horizontally extensive positive charge region that extended to the west. This IC negative leader development triggered the upward positive leader from the tower. The upward positive leader did not branch before reaching cloud base and then transitioned to horizontal propagation and branched profusely with the decayed branches producing recoil leaders. Additionally, further west (left) downward positive leaders emerged from the previous incloud negative leader pathway and these also branched profusely while transitioning to mostly horizontal propagation along cloud base and in the direction that the incloud negative leader previously propagated.Triggering flash: IC portion of a hybrid CG-IC flash, Triggering component: negative leaders, Subsequent m-components or return strokes detected at the tower: none.
Flash #13, 06:24:15 UTC. Negative leaders associated with an intracloud flash triggered an upward positive leader from the tower. The upward positive leader exhibited low-level branching and branched profusely while propagating upward. Numerous recoil leaders developed on decayed positive leader branches as the upward leader grew toward cloud base and the upward positive leader transitioned to horizontal propagation upon reaching cloud base. One branched remained luminous long after all other branches decayed and this branch exhibited numerous recoil leaders that connected with the tower. Interesting, there was a bright event around 06:24:15.9 UTC that illuminated the foreground suggesting a CG or intense IC behind the camera. Following this event, negative leaders propagated into the field of view from behind the camera. Correlated with this intense luminosity increase, the brightness of the upward positive leader channel decreased significantly suggesting an electric field change unfavorable for continued positive leader growth. This could happen due to a nearby -CG return stroke or intense -IC in which a negative field change occurs especially if the upper positive leader portion of the leader network grows significantly following the impulsive event. However, no impulsive events were recorded by Earth Networks so it is unclear what caused this intense luminosity increase and below cloud negative leader growth near the camera. Triggering flash: +IC, Triggering component: negative leaders, Subsequent m-components or return strokes detected at the tower: 16 (12 CG, 4 IC)
A summary of the 13 analyzed upward flashes showed that 11 were caused by preceding +CG flashes and 2 by IC flashes. Incloud negative leaders passing near/over the tower triggered the development of an upward positive leader from the tower in 12 of the cases, with a +CG return stroke triggering an upward positive leader in the remaining case. 3 upward positive leaders exhibited no branching prior to cloud base while 9 had low-level branching and 1 mid-level branching. Of the 10 upward positive leaders that reached cloud base, all transitioned to horizontal propagation while branching extensively with many of the branched positive leaders decaying and subsequently developing recoil leaders. In total, 67 negative impulsive subsequent events were recorded by Earth Networks at the tower location with 43 indicating CG and 24 IC.