Dan Robinson
EF5
This day, we had a little puff of southwesterly upper level support going overhead with southerly winds at the surface. Persistent rain and clouds had prevented us from destabilizing, however - so I was not expecting much. I went south of town to look at a cluster of weak showers that had formed between Fayetteville and Venedy, Illinois, southeast of St. Louis. When I got my first look at the westernmost updraft, it was surprisingly organized with a large base and a lowering:
I quickly intercepted this at St. Libory, watching a rapid circulation approach and pass nearly overhead as a very distinct RFD cut wrapped around it. This was despite the shower's radar echoes nearly completely vanishing during the previous 20 minutes! This would have undoubtedly produced a tornado had it been able to maintain a stronger updraft, and I would not be surprised if it actually did before I was able to get a view of it. There was also no discernable couplet on radar velocities, presumably due to the lack of precipitation to facilitate reflectivity.
This is a 10x timelapse of the circulation approaching me at St. Libory:
I quickly intercepted this at St. Libory, watching a rapid circulation approach and pass nearly overhead as a very distinct RFD cut wrapped around it. This was despite the shower's radar echoes nearly completely vanishing during the previous 20 minutes! This would have undoubtedly produced a tornado had it been able to maintain a stronger updraft, and I would not be surprised if it actually did before I was able to get a view of it. There was also no discernable couplet on radar velocities, presumably due to the lack of precipitation to facilitate reflectivity.
This is a 10x timelapse of the circulation approaching me at St. Libory:
