May 8 Chase

The day started like any other day. Alarm goes off at 7:30. Roll over. Turn on The Today Show. Everything is normal for about 15 minutes. Then, to my surprise, WTVA cuts in for a tornado warning issued for a storm just southwest of Tupelo. This piques my curiosity and I roll out of bed to fire up the computer and analyze the storm. Sure enough, this was one impressive looking supercell that formed on the northern edge of an instability axis and in an area of high low-level wind shear. Shortly thereafter, a tornado causes EF-3 damage along the main business strip in Tupelo, including the Barnes Crossing Mall. The storm continued to maintain an impressive signature until it encountered more stable air in northwest Alabama.

Tim and I watched for new storm development along the cold front entering northwest Mississippi for a good part the morning. While the storms were certainly healthy looking on radar, there were no warnings being issued, despite the storms moving into an area of increased instability (MLCAPE > 1000 J kg-1). As the line/cluster of storms got close to Starkville, we decided to jump on Highway 82 and intercept a couple of rogue storms ahead of the main line near West Point.

As we drove north on Alternate Highway 45, the storms to our northwest were certainly interesting and showed hints of a rain free bases at times. However, the storms quickly became outflow dominant on top of West Point and we were slammed with the rear flank downdraft and blinding rain. We decided to drop back south and head east on Highway 82 to get ahead of the storm. As we did, other storms near Starkville lead us to take a closer look at them. We didn't see anything impressive initially with those storms, so we trucked back east on 82 until we were just west of Columbus. We sat up at a new gas station on the Highway 45 exit and observed an impressive shelf cloud and a set of rotor clouds along the leading edge of the line. We snapped a few images and then decided to head back south to get a closer look at the storms moving out of Starkville.

As we did, these storms never really got their act together and quickly moved off to the east until they intensified in west Alabama. At this point, we decided to call off the chase because we noticed the storms weren't able to sustain themselves at a severe level for a long period of time. Our meso analysis suggested that subsidence on the back edge of a shortwave may have contributed to warming aloft and probably weakened the updraft accelerations in the storms. Nonetheless, it was a cool local chase and was worth seeing the rotor clouds. However, our attention was focused on May 10...