Development of Storm Towers Lead to Eventual SuperCell Chase, Howard, and Northwestern Mitchell Counties, May 14th, 2008

The mid to latter afternoon of May 14th proved to be an interesting weather event for north-central and north-eastern portions of the Permian Basin. The 1200Z MAF Skew T diagram revealed high CAPE values and strong speed and directional shear at the 850MB to the Equilibrium Level. An approaching Upper Level Closed Low over south central New Mexico continued to advance eastward, promising height falls and divergence aloft, and during the early morning hours the nocturnal Low Level Jet had advected abundant surface Gulf moisture west and northwestward across the eastern and central Permian Basin where morning dewpoints registered in the low 60's. A slowing advancing cold front,trailing from upper troughing over the northeastern United States was working its way into the northern Permian Basin and a sharpening dry-line was evident in the far western Permian Basin setting the stage of a Triple Point focus between the moist, cold, and dry boundaries. Water vapor imaging at 1700Z denoted a dry-slot from leeward exiting around Upper Low in New Mexico contributing to steep mid level laspe rates. By 1800Z it became apparent that the northwestern trending 850 MB Theta-e ridge extending from Del Rio to Midland to Hobbs was to remain and afternoon surface heating had already initiated convection in southeastern New Mexico. A Tornado Watch was issued by the SPC near this time due to the strong shearing profiles which produced values over 60 knots of effective bulk shear. The author left Midland downtown at 1900Z intending to target Martin County, east of developing Storm Towers in Andrews County, at the southeastern extent of current convection along the Theta-e ridge where adequate unobstructed surface moisture from the south and east would be available. The first image is a radar capture taken of previously mentioned developing Storm Towers in Andrews County. The second image, below, is a photo of the building convection as viewed from SH 349 at the Martin/Midland County line looking northwest (movement is from west to east or left to right on image). The next image is another radar capture taken approx-imately at 2000Z just south of the intersection of SH's 176 and 349, Martin County awaiting the southeastern side of intensifying storm to pass over. The author's vehicle is noted as the small white figure at center of concentric ring bands. The radius of each band from center of vehicle is 10 miles for scale.
A short time later the next photograph was taken noting the advancing circulation center on the southwest-ern side of storm. The following image is from beneath the updraft circulation center under the Rain Free Base as it crosses SH 349 around 2015Z.













The next several images are viewing the passing updraft circulation center from behind, looking east from west. Note crisp Storm Tower above updraft intake area on second image from this set.













The author continued to pursue the storm from behind and paralleling the movement by turning onto SH 176 where the next several images were captured from a road side rest area, several miles east of the SH 349 intersection at 2025Z and showing the ragged updraft area with slightly rotating wall cloud (foreground at left-center) and associated fractus cloud, beneath. A radar capture is included showing the position of the author's truck at center of concentric circles in relation to the viewing of photos with respect to storm's position. Cloud heights according to Mobile Threat Net (Baron software) at this time were 30,000-35,000' and had not yet reached Equilibrium Level. The author continued east along SH 176 until intersecting SH 137 where a turn to the north of said highway was taken until reaching RR 846 in order to turn east again, approximately 2045Z, where the next photo indicates a lowering of the tilted storm's updraft (vertical cross-sectional view) with associated inflow band as viewed from southeastern prospective. Also at this time it became apparent that the storm was taking on SuperCell characteristics as strong RFD winds were encountered as noted from right of image and also shown from zoom of dust blowing toward the southeast in background on backside of updraft.













The author continued driving east on RR 846 into Howard County following the southwestern side of the updraft intake area as shown on the following images













Note on the next image, lower left, the low angle(referenced from horizontal) tilted storm Tower associated with the updraft region as viewed from behind indicating strongly sheared troposphere preventing the tower from reaching the Equilibrium Level. The next image is taken from RR 846, near Knott, approximately 3 miles west of SH 87 in north-western Howard County, looking ENE, at ragged lowering of updraft intake (partially obscured by initial RFD occlusion), as viewed from the west looking east (storm movement is a little right of parallelling the road), as the storm was thunderstorm warned by NWS/MAF. A radar capture was taken at this time showing a well developed V-notch indicating good ventilation of the updraft with difluence aloft.












Shortly thereafter, approximately 2145Z, NWS/MAF also tornado warned this evolved SuperCell. The author turned down RR 1205 in northeastern Howard County and proceeded south until after crossing the intersection SH 350 and approximately three miles south marble size hail was witnessed along the RR and adjoining off road topography as seen in following image. The following image, as viewed from west, reveals how the northern Tornado warned SuperCell was eventually starved of southeast low level ingested moisture from a competing cell developing to its east and southeast and eventually began to lose its crispness and began gusting out at the expense of competing/interferring storm. View is looking east from RR road 1205 approximately 10 miles north of Interstate 20 into Mitchell County.


The intensifying developing cell which choked the chased Supercell reportedly dropped golfball to baseball size hail near Colorado City, Mitchell County. The final image is regional radar view with surface winds noted by streamlines showing surface low cyclogensis in extreme southeast New Mexico and the author's truck at center of concentric rings west of Colorado City at approximately 2215Z. If zoomed, clicking on image, the competing eastern storm centered over Colorado City is shown intensifying and the chased storm by author seen as diminishing to west and northwest. Note that Midland at this time was on the west side of advancing dry-line with southwest winds. The chase was terminated and consummat-ed with a cheeseburg-er from Town & Country in Coahoma.