False Signal at Back End of Supercell

Here’s a quick, classic example of where meteorological situational awareness plays a large role in storm interrogation while using the NTDA/NMDA algorithms. A first look at Base Reflectivity shows higher probabilities of NTDA/NMDA at a position of the supercell well detached from where you would commonly expect strong, deep rotation (notice the BWER also in the top left, cool!).

2157Z 7/19/18 KDMX. Top Left: 0.5º BR. Top Right: 3.1º BR. Bottom Left: BR 4.0º. Bottom Right: BR 5.1º.
2157Z 7/19/18 KDMX. Top Left: 0.5º SRM (Storm motion 280º at 18kt). Top Right: 3.1º SRM. Bottom Left: SRM 4.0º. Bottom Right: SRM 5.1º.

Sure enough, looking at SRM confirms messy and anomalous values of SRM likely associated with the back end of a boundary or front. Another example of anomalous values from both algorithms and how situational awareness can avoid miss identifying aspects of a supercell.

– Dusty Davis