Rotating Mesocyclone Contributing to Significant RFD Winds, Tornado, and Later Rotating Impressive Wall Cloud Near Ground Level, May 27, 2008

A very spectacular Mesocyclone (Classic SuperCell) was observed late afternoon on May 27th in southwestern Dawson and northwestern Martin counties near the townsite of Patricia, Texas. The author left Midland at approximately 0015Z and captured the first image from SH 349, one mile north of Loop 250 N, of the exploding Supercell, looking from south to north (storm motion is from west to east or left to right on image. The Supercell demonstrated a strong updraft Storm Tower by noting aloft extending upwind (west) anvil and an overshooting top which was higher aloft just moments prior to this image capture. The author proceeded north along SH 349 until arriving at the Seminole Pipeline Compressor (Patricia Station), approximately 10 miles south of the townsite of Patricia where the next series of images were taken. The first image of this series was taken at approximately 0040Z, looking northwest, at saucer shaped Rain Free Base with lowered Wall Cloud sloping toward the precipitation core with attendant Tail Cloud, center background, and Clear Slot, left background. Panning toward the east of the previous picture the next image was taken to demonstrate two inflow"beaver's tail" bands transport-ing moisture into the updraft core.

The next image is looking toward the western portion of the updraft base, in foreground of RFD Clear Slot, noting cooled humid condensed moisture vapor and dust being lifted (interaction between cool RFD and warm low level southeast inflow). The next image is a sepia of the previously discussed Wall Cloud and Clear Slot wide angle view, captured moments earlier of previous picture, to illustrate finer detail. Next is zoomed region of condensed water vapor and dust, left of image, being pulled from ground level into updraft from western side of rotating storm base and noting a sharp western escarpment, descending (Wall Cloud), right of image.

The rotating updraft base continued to advance southeastward and the next image (sepia) shows a hidden Tornado in swirling farm plowed fields just to the left of SH 137 and northwest of the intersection of SH 115 at 0105Z. Note the Tail Cloud on east (right) side of dust swirl and western escarpment of Wall Cloud on west (left) side of dust swirl. The tornado is hard to see but is the cone shaped dark image directly in the center of the dust debris cloud. Another view of the hidden Tornado (color version), noting Clear Slot on left (west) and precipita-tion core on right (east). A radar capture was taken at this time in order to show positioning of observation.















Shortly after the passage of the Tornado across the SH 137 projection the author began to encounter strong RFD straight line winds estimated at 60-65 mph as noted on the next image, looking east across SH 349 at obscured oil field tank battery (moments later, once returning to the truck, a strong RFD gust, estimated at over 80 mph roared across limiting visibility to less than 50 feet and rocking the truck). The author proceeded north along SH 349 taking a position approximately 5 miles south of Patricia along a eastern exiting oil field road in order to capture the next series of images. The next image is taken looking east from aforementioned locale at swirling red farm ploughed dirt being pulled into rotating Updraft Base, with lowered Wall Cloud just to the left background of red swirl. The next image shows a horizontal Fractus condensa-tion trail wrapping into the updraft center from northwest with. The next image reveals, vividly, the lowered Wall Cloud, once dissipation of vortex, as viewed from the west at approximately 0120Z. A radar capture was taken at this time to show positioning of photograph-er with respect to storm updraft circulation. The next several images are presented in sepia format to better define detail of descending Wall Cloud to almost ground level.

















The final image is looking up at the Storm Tower's updraft as viewed from west.

HP SuperCell Evoution into Multicell "Bow Echo", Southeastern Ward and North-Central Pecos Counties, Texas, May 25, 2008

The setup for Sunday afternoon was favorable for severe convection due to abundant instability (low level moisture coupled with adequate steep mid and lower lapse rates; SBCAPE values exceeding 3500 J/kg) and adequate speed/directional shear (>30knot effective bulk shear). The only question remained in what manner would convection be initiated being that a deepening Upper Level Low had retrograded further to the west, centered in southwestern Arizona, providing southwesterly winds aloft but with less speed maxima. A potential sharpening of the dryline appeared to be the best source of lift during the afternoon and early evening hours before loss of solar insolation. The SPC placed the western, northern, central, and southern portions of the Permian Basin under a severe thunderstorm watch during the early afternoon until early evening. The author left Midland at 2045Z, targeting convection initiation along the dryline near Pecos, Texas along interstate 20. The above radar image was taken in route at 2115Z to emphasize the targeted HP SuperCell which had just been tornado warned by NWS/MAF.

At a position just to the west of Odessa the first digital image, below, was captured viewing the spreading anvil over interstate 20, looking southwest at sheared storm tower, background lower center, apart of the Rear Flanking Line. The next image is a zoom of the overhanging anvil from the same position looking directly overhead noting impressive

Mammatus cloud formations. The author continued west on interstate 20 with the intent to turn south on SH 18, south of Monahans, in order to position along the southeast side of the evolved SuperCell. It was noted as driving toward this positioning that frequent cloud to ground lightening was occuring beneath the anvil canopy. The next image is of a grass wildfire ignited by lightning near the intersection of SH 18 and RR 1776 south of Monahans at 2155Z.

The following two images are, first, a radar capture at 2200Z along RR 1776, near SH 18, showing position of author's truck with relation to storm and, second, a photograph of saucer-shaped Rain Free Base, as viewed from the northeast looking southwest.

The next image portrays a lowered wall cloud, partially obscurred by rain,beneath storm base, as storm advances toward author. The radar capture, at 2215Z showing the position of the author's truck at the intersection of RR 1219 and SW 18 just north of Grandfalls. hook .

The author had to continue southward along SH 18 due to the advancement of the main updraft core which was to the southeast. The next image is south of Grandfalls at 2300Z looking west at rain cooled moist inflow toward updraft.

The following image is capturing the southeastern side of storm base, as viewed from the east, revealing inflow band into storm base from the south.

The next image, above, was taken a short time later noting larger, south entering, inflow bands into the Rain Free Base area.

Moist cooled air continued to condense near the circulation updraft as noted on the next image, left. Rotation was suggested by noting the storm tower's updraft base, next two images, demonstrating coiled striations.

Last indication, as noted on next image below and subsequent radar capture at 2330Z, of moist inflow into this SuperCell lowered updraft intake before morphing into a squall line due to strong rear inflow jet dominance, noted on last radar capture (last image), which eventually formed a "bowed"multi-celled squall line.

But before losing its once dominate status the updraft performed the best visual presentation of a lowered Wall Cloud with small associated Tail Cloud pointing toward the precipitation core as the Updraft neared SH 18 between Grandfalls and Ft Stockton. The next image is a zoom of the previous, moments later. Another view of the Tail Cloud up close.

The last image, below, is a radar capture of the bow echo configuration noting the strong rear inflow jet notch to the northwest of the author's truck, at center of the concentric rings, where straight-line winds were estimated at 65 mph when encountered shortly thereafter.

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.