NMDA detected over a weak TOR without NTDA detection

There was a public report of a small tornado just east of I-25 in CYS’s forecast area at 20:54Z. Base velocity data from the KCYS radar was pretty unimpressed showing some weak rotation at 20:51Z. The NTDA didn’t have a detection with it but the NMDA was detecting a meso with a medium azShear Max and low azShear Average. The stronger rotation was above the 0.5° with the NMDA triggering on the 0.9 to 2.4° tilts. I’m unsure that would have provided enough confidence to issue a tornado warning. But the NMDA could’ve given some clue to the potential for a tornado. There was no SAILS data for this event, so maybe if we had additional 0.5° scans then we would have seen a stronger rotation signal in the base velocity.

PUBLIC REPORT OF A SMALL TORNADO 1/2 MILE TO THE EAST OF INTERSTATE 25 AT MILE MARKER 34 | Laramie County | 25 miles N of Cheyenne
0.5, 0.9, 1.3 and 1.8° tilts from the KCYS radar at 20:51Z.

– Gerry Bertier