With much anticipation and planning, my first storm chase of the 2012 season on March 18 was a successful one! One tornado and one funnel cloud were observed, the funnel as it was occluding and the tornado during its entire 3 minute length. The entire trip took 15 hours 35 minutes, drove 772 miles, and cost $104.44 in fuel.
The Storm Prediction Center had issued a ‘Slight’ risk of severe thunderstorms across the southern and central plains. Rich instability approaching 3000 J/kg was available across Texas and far SW Oklahoma, decreasing to about 1500 J/kg into Kansas. Marginal bulk shearing existed across Texas however, which would support messy storm development. Better wind shearing was expected to arrive near sunset across the TX Panhandle, west Oklahoma, into Kansas. A strong cap was expected to sit across most of the region, but possibly erode near the dryline due to strong daytime heating and the approaching upper level trough.
With this information I saw two potential chase target areas. NW Texas into the eastern TX Panhandle where the cap would likely erode faster, higher instability values existed, but less ideal wind shearing would be present. Or southwest Kansas and the eastern OK panhandle where lower instability existed, the cap was stronger, but where much better wind shear would arrive near sunset. I decided to target the town of Shamrock, TX first. Shamrock is on I-40 in the east Texas Panhandle, 10 miles from the OK state line. This position offered a good compromise in my opinion. It was located in the middle of the SPC’s 5% tornado risk area, plus afforded the ability to easily intercept any storms that developed within 100 miles as I had good road options in all 4 directions.
I arrived in Shamrock, TX a few hours early which gave me time to reevaluate computer models, watch the radar, and eat some food. After an hour or so I drove up to Canadian, TX on the hunch that storms may initiate near that area by the time I arrived, but unfortunately was mistaken. I drove back to Shamrock and found the large cluster of severe storms which had been ongoing for about two hours to my south were still going strong. One cell had not only moved out of the cluster and become more isolated, was also moving into an increasingly favorable environment for tornadic supercells. I was about 1 hour driving distance from an intercept, and at 6:12pm CDT I decided to target it.
Back in Shamrock TX, using live radar data I decided to target the right moving supercell which was emerging out of the storm cluster. The right mover is near Hollis OK at this time. The left mover moving due north across I-40 shows anti-cyclonic rotation, but this is deceptive. Targeting right moving supercells is the safe bet. Many times left movers will show rotation but fail to produce any tornadoes. There are exceptions to this rule (Greensburg Kansas eF-5 tornado was a left mover) but the odds are the right mover will produce while the left mover does not.
No photos found for specified shortcode
|Driving south along the western edge of the storm, I saw this beautiful rainbow. I chose this route to avoid core punching… no need to lose a windshield!|
I was able to intercept the storm just after 6:50pm CDT, the storm had just produced a brief tornado near the road I drove on. I punched through the southern tip of the hook and saw the tornado as it occluded just north of the roadway. The funnel occluded very quickly and the video I shot of it was very brief and poor.
No photos found for specified shortcode
A few more stills along State Road 34 between Magnum and Willow Oklahoma.
At 7:38pm a new tornado developed about 4 miles to my northwest. I was located about 5 miles east of Willow OK at the time, so my estimate was that this tornado was perhaps 2 miles NNE of Willow OK at the time.
The long elephant trunk tornado lasted about 3 minutes, no known damage was caused by this.
The tornado occluded and I remained in this same position watching for another 10 or so minutes before continuing forward, violating my own promise to myself to avoid chasing on dirt roads. In my own defense however, it had not rained at this location and the roads were passable.
I continued following this storm through until after sunset and after twilight ended around 8:30pm CDT . Stronger subsident air was beginning to set in, and the storm was losing intensity. I decided to end the chase and return home to the D/FW Metroplex, a 4 hour drive.
I consider it a successful first storm chase of the season with 1 confirmed tornado observed, 1 funnel cloud, and zero hail dents to the rental car!