Thursday, May 14, 2015   |   Case Studies

Case Study: Van, Texas EF-3 Tornado

On the evening of May 10, 2015, a strong EF-3 rated tornado moved through the town of Van, Texas, injuring nearly 50 people and causing two fatalities.

This case study examines the formation and path of the tornado, and the performance of Baron alerting algorithms during the event.

 

van_tx_837pm_ref8:37 PM
Less than 25 minutes before the tornado entered Van, the storm that produced it was located about 10 miles south-southwest of the town. At this point, a Baron shear marker and severe storm SCIT (Storm Cell Identification Track, shown as a pink arrow) have been automatically triggered by deteriorating conditions. The arrow points in the direction of the town.

van_tx_837pm_vel
Velocity data at that same time reveals some rotation beginning to occur within the storm.

 

 

 

 

van_tx_847pm_ref8:47 PM

10 minutes later, the storm is rapidly approaching the town. It’s better organized now, with numerous shear markers indicating the presence of wind shear. A Baron shear SCIT (orange) has been triggered, pointing directly at the town of Van.

 


The SCIT above signals when the first “Twisting Storm Approaching” alert was automatically generated by Baron algorithms, about 12-15 minutes before the tornado moved through Van.
It is also around this time that the initial touchdown occurred on farmland to the southwest of the town.

 

van_tx_847pm_ref_in_close

A close-up of the triggered alert, and the area affected.

 

 

 

 

 

van_tx_852pm_vel

8:52 PM

The next velocity scan shows a very small but strong rotation very near the town of Van. Shear of 92 mph was being detected at this time. Three minutes later at 8:55pm, a Tornado Warning was issued for the area.

 

 

van_tx_857pm_ref8:57 PM

On the 8:57 reflectivity scan, a low-level shear marker is still visible with the storm. Both the marker and the heaviest reflectivity returns were very near the town at this time.

 

 

 

van_tx_907pm_ref9:07 PM

Ten minutes later, the storm has moved well past the town of Van, with the tornado lifting off the ground. The Baron shear SCIT from the previous scan has been replaced by a severe storm SCIT.

 

 

van_tx_905pm_velVelocity data from the same scan shows very little in the way of rotation at the altitude the data was being sampled, which was nearly 9000 feet.

 

 

 

 

Below is a visualization of the Baron weather alerts (blue) generated for the town of Van, beginning at 8:47 PM, along with the issued National Weather Service Tornado Warning (red), which was issued at 8:55 PM.

google_earth_nws_van

 

 

 

 

 

 

 

 

 

Broadcast customers subscribing to Data Essentials receive Baron SCITs. Other value-added data like Baron Shear Markers, TDS Indicator, Baron Button and others are available to Data Innovations subscribers.