Caprock Magic

Tonight was quite the treat for those who got out to chase a lone supercell just west of Amarillo, TX, in Bushland, TX. SPC had the area highlighted as general thunderstorms, with a "see text" just north of the Texas panhandle. The tornado probabilities were labeled less than 2% across the CONUS. You can view the outlooks for 4/20/10 here. The following is a synopsis of the event, including pictures of the tornado by CTV/DM storm chaser Brandon Green.

We'll begin by taking a look at the surface. As you can see, there is a low over New Mexico, about 100 miles W of Amarillo, TX. The surface obs. in Amarillo were 58/54, which were a little cooler than the surrounding area, but the same dewpoint.

Also below is a visible satellite loop with some added commentary. A boundary is clearly visible on satellite imagery, running primarily in a north-south direction. This boundary can bee seen throughout the entire loop with the exception of the last few frames. While it may not be easily visible at those times, it is clear where it is by looking at storm initiation off this boundary. I have also circled the tornadic supercell in the animation, as well as labeled the time that the tornado was on the ground.

Now we'll take a look at the environment during this event. The following are forecast model skew-t diagrams, and hodographs. The skew-t diragrams both showed a little cap, or inversion at about 800mb, with CAPE values near 1000 J/kg. The lower level winds are also pretty decent, with nice turning of height, creating a nicely looped hodograph which correlates with rotating updrafts.

Next we will look at an atmospheric parameter. Shown below is the surface vorticity, divergence, and convergence map at 0z (about the same time as the tornado). Divergence is shown at the surface near the tornado, and vorticity is also decent at 8-12 units (10^-5/s).

Finally, here are a few screenshots of the radar, and actual images of the tornado taken by chaser Brandon Green.