Early on in convection, funnel clouds and tornadoes were being reported in small storms with virtually no rotation on radar. Once there was sufficient rotation on radar, it appeared that funnels/tornadoes were being reported with NTDA probabilities as little as 30%. Normally I would take notice, but not warn, on such low numbers. Given the earlier storm reports, when an NTDA marker first appeared for the Marshall County cell I had a feeling that it would eventually produce a funnel or tornado. The first detections were very low, only about 20%, first around 2059Z and then again around 2109Z. By 2110Z it had jumped to 30% with a hook evident on radar and rotation on the few lowest tilts. It was at this point that I would have warned on this storm. The radar data may have been enough alone at this point, but the first detection at 2059Z definitely drew my eye to this area and I knew it was something I needed to keep an eye on, despite being distracted by the much larger supercell in Marion County.

By 2113Z the NTDA probability had increased again to almost 44%, and at 2116Z it was up to 56%. A funnel cloud was ported at 2117Z, with tornado reports following around 2122 and 2130Z.

– Angelica Schuyler