Tuesday Practice Case

A sudden yet steady increase in DivShear helped lead to an earlier lead time on a tornado warning when rotation in velocity was apparent but still generally weak.

AzShear was medium leading up to the tornado reports and only jumped up after reports started coming in around 12:20z.

Spectrum width, which I would generally rely more on in the absence of these new tools, had a general positive trend through this period, but plateaued in the minutes leading up to the tornado reports.

The absolute maximum of velocity trend was low leading up to the tornado reports and only suddenly increase afterwords. Essentially, just relying on strong rotational velocities in this case would have resulted in no lead time for the initial reports.

TORP, while sometimes slow to update in AWIPS compared to the online tool, helped highlight an area of weak vrot where a tornado was likely ongoing based on storm reports at the time. (If not a tornado, there were at least several TSTM WND DMG reports.

While TORP only remained around 50%, both AvShear and DivShear highlighted an area of strengthening rotation that may have been associated with a brief tornado, including a clover pattern present in the DivShear. Neither of these features prompted a tornado warning, but confirmed suspicions immediately after the warning was issued based on the velocity pattern.

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