Norman’s lights illuminated the condensation funnel of a small, autumn tornado in the southwestern corner of the city. Instead of being produced by a supercell, this was a squall-line tornado, also known as a quasi-linear convective system or QLCS tornado in the acronym-thirsty meteorological parlance. It’s rare to see a QLCS tornado, and even rarer to see one at night. I don’t recommend folks try, unless they have extensive storm-spotting experience over many years. I wasn’t even out to see a tornado, but on a high spot hoping to shoot a shelf cloud. Instead, this spun up in a small-scale mesocyclone behind the gust front, where some surface-based inflow still wrapped in. The tornado’s visible edge was a little sharper than shown here, because of its movements during the short time exposure I needed to make to get it illuminated enough. I first saw this tornado a minute or so earlier as a fuzzy cloud-base circulation and lowering, with no visible funnel, but somewhat translucent, faint debris cloud and power flashes. That was about the time the warning came out, and when it struck the Riverwind Casino, where the Beach Boys were playing to a sold-out crowd, including the Oklahoma governor. This had the potential to be a major, mass-casualty event had the tornado been stronger.
Norman OK (21 Oct 17) Looking WSW
35.1921, -97.373