Strange Catch

Watching a line of strong storms over western Illinois that collapsed into an approaching outflow boundary, I stuck a camera out the window and shot continuous in the hope of getting an arcus cloud illuminated by intermittent lightning. On arrival it was somewhat disappointing visually although there was a fairly significant gust front that made things a little breezy till it passed. What would be interesting though is that on review of the images, those which had the only available lightning being generated by a small cell going up ahead of the main line revealed the possibility of either a brief landspout or leading edge spin up. The cell was lifting from the SW whereas the surface outflow was traveling SE. The small scale shear as result of this boundary interaction may have been enough to create a short lived vortex that would quickly be undercut by the incoming gust front. Velocity from this time shows a very weak curl and upon consultation with the local weather service, they concur it may have been. The moment will forever remain inconclusive but I thought it was worth a blog post. Though unrelated to this incident, a separate overnight storm up near Chicago produced a brief EF0 Tornado.









Animation sequence with only the lightning captures.


Full animation, note directional change with outflow passage.