A storm northwest of Goodland had a Torp object identified on it around 29% at 2323 UTC but then the next volume scan jumped to over 50% at 2326 UTC as the storm began showing a more prominent hook and AzShear values increased as well. Again the trend charts are very useful for keeping track of storm intensity history.

Flash

Noticed a band of high negative DivShear along the line of storms where several LSRs of 59mph, 60mph, and 63mph winds were reported. This signal decreased as the line pushed east, and we have received no LSRs since then. Base products corroborate this too, with generally decreasing velocities and a weakening reflectivity gradient. -Sidney Crosby

Despite some Cave issues at the start of our real-time case, looking at the Torp on the Phi Tool, there was a storm that had an object identified with a history and it was encouraging to see the values drop off significantly as the velocity data was weakening as well.

Flash

21:15z: AzShear first caught my attention for an area to watch. Object marker quickly appeared and velocity indicated a very weak area of rotation. Next few scans showed the TORP probability increasing. This resulted in issuance of a tornado warning with ~4 minutes of lead time.

Top image: Weak velocity signature.

Middle image: First indication of AzShear picking up on an area and first object marker highlight.

Bottom image: TORP marker in AWIPS when decision to warn was made.

The highest the TORP probability got was 29% right around a couple minutes before the tornado report came in west of Corning, CA. 10-15 minutes before the tornado report came in, the 10-15 minute pre-tornadic probabilities were in the 39-41% range, possibly highlighting a slightly higher potential for a tornado later on (and it happened!).

Kilometers

I noticed that when the “Aggressively-Filtered” TORP objects (likely sampling mountain peaks) were displaying the 5,10,15-min tornado probabilities, they would decrease or jump around or increase. In all of the other cases, the probability seemed to only increase with the greater amount of time. Once we finally got a TORP object sampling a real storm off KBBX, the probabilities only increased as you got closer to the 30-minute time frame, matching what I would expect and what I was seeing in all of the other cases.

Kilometers

Noted a DivShear increase along that thin line of precipitation as it increased in intensity and started to produce several lightning strikes.

Kilometers

It was interesting to see a Torp object identified due west of the BBX radar around 21 UTC with really weak reflectivity and what looks like suspicious velocity data with AZshear in the high category for almost 20 min. This is interesting that this one persists even with the “display aggressive filtered objects” off.

Flash

In the morning supercell case set in OUN CWA, I looked at the pretornado probabilities on the second warning I issued and found it interesting and encouraging that the 5-30 min pretornado probabilities showed increasing values at all 5 min time steps and were higher than the observed Torp probability which added some confidence in the detection and confirmed what I was seeing in the base radar data.

Flash

In this case which involves significant terrain on each side of the valley, Torp objects were identified for many areas where poor velocity data in the higher terrain was observed when turning on the “Display aggressive filtered auto objects”. However, when this is turned off almost all of the Torp objects are removed so it appears the filtering technique being employed is working as intended at least early on in the case.

Flash