Friday, March 02, 2007

Two rather unsuccessful chases in the past 10 days... Alas, it's only March 2nd, so I'm not too disappointed yet. I was extremely surprised by the tornadic supercell that produced a few tornadoes (one of which was strong to violent) in southeastern Kansas last Wednesday. We also just wrapped up a significant tornado event in the southeastern U.S. yesterday. I wouldn't really call it an "outbreak", but it was a significant tornado event nonetheless. I happened to take some screen grabs from GR3 of a tornadic supercell as an EF3 tornado was churning through the southeastern Alabama town of Enterprise. Unfortunately, the tornado killed more than a half dozen folks in that town, many in a high school.
This blogging software automatically reduces the size of the image, so I suggest the full-size image HERE. If you aren't familiar with radar imagery, the most important things to identify are the hook echo (the "arm-like" feature of higher reflectivity that protrudes to the southeast from the west part of the storm above) and the "damage ball". This "damage ball" signature is caused by large amounts of debris being lofted by a tornado, which is exactly what was happening in the town of Enterprise. While many tornadoes loft debris, few are close enough to weather radars for the associated near-surface debris field to be sampled by a radar. See below for more imagery:

Reflectivity (tilt 1)

Storm-relative velocity (tilt 1) -- note the two intense couplets, indicating the potential of two tornadoes occurring at that time.
Storm-relative velocity (tilt 2)
32NM Base Velocity 1
32nm Base Velocity 2