Amos Magliocco
EF5
Chase Report: May 27, 2004 N TX Supercells
We chased three severe storms in north central Texas this afternoon and evening and witnessed a microburst that caused injuries and damage in Comanche County Texas. I nearly became a victim myself as I witnessed my first flying structure in close proximity---something I thought was a Port-O-Potty sent to doom me to an MTV "Jackass" style chasing death.
We started in Elk City and thought Thursday was an off day. On our way to breakfast, I grabbed my copy of Tim Vasquez’s Stormchasing Handbook and searched for cool places to visit in Central Oklahoma. We settled on a ghostown not too far from Elk City then a trip up Mount Scott for some photos and sightseeing. However, after we ate, we took another look at data and noticed the 12Z ETA was much more encouraging than the 12Z RUC had been, and our analysis of current conditions showed the energy moving into the southwest Texas region was relatively formidable. We considered that the surface features might react more favorably than the models showed. We elected to play the nose of the midlevel jet streak tracking from southwest Texas into the Abilene area.
A vorticity lobe out ahead of the main energy caused showers and storms to persist for much of the late morning and early afternoon, but as these were high based and somewhat limited in coverage, I still believed our boundary layer was in fine shape. Also, winds just east of the dryline were backing nicely as a strong punch arrived on 30 knot plus westerly surface flow. Our low level jet was forecast to strengthen by the RUC, addressing our biggest concern—low level wind fields. Ultimately I think the weakness in this region of the vertical shear profile limited the lifespan of storms that organized later.
We stopped for data and sandwiches in Haskell, Texas, where I pulled up a radar and found a tornadic supercell already rolling through Fisher County just southwest of us. This tornado had produced damage east of Sweetwater, according to the warning, so the chase was on. We raced the storm to Lueders and, as we rounded the front side, the cell weakened and choked on the surrounding rain. We pushed south to Abilene and moved east on Interstate 20 where we soon caught up to another supercell forming along the leading edge of the gust front and producing four inch hail in Stephens County. Around Strawn, we observed a very ragged and disorganized lowering with a tail cloud, but all high based and non-threatening. As this storm was flying northeast at forty knots, we elected to drop south for the next organizing supercell taking aim on Stephenville in Comanche County. As we approached the city, the storm developed some rotation and a TVS signature (according to WeatherTap’s RadarLab software), and we observed another lowering, this one much closer to the ground, hanging from a solid updraft base.
We continued south on 281 out of Stephenville to maintain our position when the storm collapsed and a strong microburst blasted across the road. These winds began with driving horizontal rain, then tree branches, and finally a large metal shed, ripped in half, that floated above the treeline and looked to drop right in front of me on the highway. I thought it was a port-a-potty since I only noticed half the structure, but I still thought a serious accident was imminent, albeit a somewhat silly one. But even a port-a-potty at 70 mph can probably finish you off. I slammed on the brakes though there was no real way to stop in time, and, like magic, the structure dropped into the ditch on the side of the road just as if someone had let it roll from the palm of their hand—this after having cleared trees at least twenty five feet tall. Needless to say, I was wide awake after that.
We later learned that residents of a mobile home suffered injuries from these powerful straight-line winds when their trailer was destroyed. We heard reports of detached roofs and downed powerlines in Stephenville and other parts of Comanche County. We radioed the report of the shed to Comanche County Skywarn, worried that another blast would lift the metal debris from the ditch into the road. After the storm gusted out, we returned north to Denton County and plan to move north from here for anything tomorrow and the big show Saturday.
We chased three severe storms in north central Texas this afternoon and evening and witnessed a microburst that caused injuries and damage in Comanche County Texas. I nearly became a victim myself as I witnessed my first flying structure in close proximity---something I thought was a Port-O-Potty sent to doom me to an MTV "Jackass" style chasing death.
We started in Elk City and thought Thursday was an off day. On our way to breakfast, I grabbed my copy of Tim Vasquez’s Stormchasing Handbook and searched for cool places to visit in Central Oklahoma. We settled on a ghostown not too far from Elk City then a trip up Mount Scott for some photos and sightseeing. However, after we ate, we took another look at data and noticed the 12Z ETA was much more encouraging than the 12Z RUC had been, and our analysis of current conditions showed the energy moving into the southwest Texas region was relatively formidable. We considered that the surface features might react more favorably than the models showed. We elected to play the nose of the midlevel jet streak tracking from southwest Texas into the Abilene area.
A vorticity lobe out ahead of the main energy caused showers and storms to persist for much of the late morning and early afternoon, but as these were high based and somewhat limited in coverage, I still believed our boundary layer was in fine shape. Also, winds just east of the dryline were backing nicely as a strong punch arrived on 30 knot plus westerly surface flow. Our low level jet was forecast to strengthen by the RUC, addressing our biggest concern—low level wind fields. Ultimately I think the weakness in this region of the vertical shear profile limited the lifespan of storms that organized later.
We stopped for data and sandwiches in Haskell, Texas, where I pulled up a radar and found a tornadic supercell already rolling through Fisher County just southwest of us. This tornado had produced damage east of Sweetwater, according to the warning, so the chase was on. We raced the storm to Lueders and, as we rounded the front side, the cell weakened and choked on the surrounding rain. We pushed south to Abilene and moved east on Interstate 20 where we soon caught up to another supercell forming along the leading edge of the gust front and producing four inch hail in Stephens County. Around Strawn, we observed a very ragged and disorganized lowering with a tail cloud, but all high based and non-threatening. As this storm was flying northeast at forty knots, we elected to drop south for the next organizing supercell taking aim on Stephenville in Comanche County. As we approached the city, the storm developed some rotation and a TVS signature (according to WeatherTap’s RadarLab software), and we observed another lowering, this one much closer to the ground, hanging from a solid updraft base.
We continued south on 281 out of Stephenville to maintain our position when the storm collapsed and a strong microburst blasted across the road. These winds began with driving horizontal rain, then tree branches, and finally a large metal shed, ripped in half, that floated above the treeline and looked to drop right in front of me on the highway. I thought it was a port-a-potty since I only noticed half the structure, but I still thought a serious accident was imminent, albeit a somewhat silly one. But even a port-a-potty at 70 mph can probably finish you off. I slammed on the brakes though there was no real way to stop in time, and, like magic, the structure dropped into the ditch on the side of the road just as if someone had let it roll from the palm of their hand—this after having cleared trees at least twenty five feet tall. Needless to say, I was wide awake after that.
We later learned that residents of a mobile home suffered injuries from these powerful straight-line winds when their trailer was destroyed. We heard reports of detached roofs and downed powerlines in Stephenville and other parts of Comanche County. We radioed the report of the shed to Comanche County Skywarn, worried that another blast would lift the metal debris from the ditch into the road. After the storm gusted out, we returned north to Denton County and plan to move north from here for anything tomorrow and the big show Saturday.
