Rogue Mesocyclone Develops near Pecos River, West of Grandfalls, and Traverses Ward, Crane, Upton and Midland Counties, October 5, 2008

A rogue mesocyclone with impressive mid level updraft rotation and descending Wall Cloud(s) was observed as it developed near the Pecos River in extreme northeastern Reeves County and eventually tracked through central Crane, northern Upton and southern Midland counties from 2030Z until 2250Z, October 5th, 2008. A second mesocyclone "sister", forming southwest of the previous, following a similar trajectory, was also captured beginning at 2250Z. Both SuperCells would be tornado warned during a portion of their life-cycle(s) by MAF/NWS.


The author left Midland around 1900Z deciding upon a target area in south-central Permian Basin were solar insolation was believed to be more abundant during the day through a broken stratus deck and improve instability . The Permian Basin was listed in a slight risk category by the SPC due to being in a favorable shear environment due to a rather strong LLJ contributing to warm air advection (Theta e ridge) beneath a strong mid level (500MB0) southwesterly flow aloft and a very intense Upper Jet (250MB) with 90K winds rounding the base of an amplified Upper Trough. The mid and upper level strong winds would provide ascent forcing due to divergence aloft. The MLCAPE was not real impressive from the 1200Z soundings due to abundant mid level warm moisture present, lessening lapse rates. Surface dew-points were near 60 degrees. The strong directional and speed shear as "progged" was believed to allow for rotation of any storm towers which developed. Cumulus development was noted when leaving Midland and some convection had already initiated in the northern Permian Basin, southeastern New Mexico and the South Plains. The SPC issued a Severe Thunderstom Watch around 1910Z and its configuration along with radar reflectivity is shown in the first image (the author would travel toward the southwest from Midland). The second image was captured along RR 1233, approximately 2 miles west of the intersection with SH 385, in eastern Crane county at 2030Z looking toward the southwest at developing storm tower's southern end. A radar capture is also included which shows the location of the storm tower near the Pecos River in extreme north-eastern Reeves county and the location of the author's truck. The author proceeded west on RR 1233 crossing the intersection of FM 1601 and stopped 4 miles west of the Waddell Compressor Station and captured the next image of lowered condensation into the improving storm's Rain Free Base at 2100Z. Included is a zoomed image moments later. The next image is a radar capture taken at approxi-mately 2105Z which also notes an improving V-notching to the northeast of updraft region demonstrating good outflow and venting of emerging mesocyclone. At this time it became apparent that this storm was a rogue and isolated from a linear multi-celled complex to the north. It would not have to compete with other cells for inflowing moisture and upon reaching mid and upper level height, directional and speed shear, should begin to allow for rotation from it's base. The author retreated back to the east along RR 1233 since the storm's direction had begun to take more of a "right turn" and in order to get a better look at the evolving mesocyclone. The next image, captured at 2130Z, reveals the impressive mesocyclone's striated updraft base and tower which had begun to visually rotate counter-clockwise.














The NWS in Midland tornado warned this mesocyclone at 2140Z. The next image is taken, a short time later, of the updraft base, rotating, and a descending wall cloud, centered over the road background, in sepia format in order to enhance the resolution. The next two images are of the engorged Wall Cloud with Inflow Tail and Fractus scud to left, the last of the two a zoomed image. The next image, taken at approxi-mately 2200Z shows the Wall Cloud becoming less robust and the tail cloud becoming detached. The author continued to back tract to the east and captured the next image around 2205Z at more inflowing bands into the updraft circulation east of the Waddell Compressor Station.

At approxi-mately 2210Z another Wall Cloud lowering was noted south of RR1230 after the author continued to drive east, as the circulation center was tracking a little south of due east. Driving back to SH 385 and turning north it was noted that there was a second updraft base seen to the southwest of the currently chased mesocyclone. The next image is of lowered condensation infow into this second evolving mesocyclone and it was taken approximately at 2250Z. A radar capture is also included for reference to the "chased supercell" and with respect to the author's truck. The next image was taken a short time later after traveling back south along SH 385 and capturing a zoomed image looking toward the southwest. It was beginning to become dark not only because of nearing dusk but because an advancing multicelled squall line approaching from the west. The next image is a radar capture of the aforementioned linear squall line playing "catch up" to the two rogue mesocyclones (image is blurred... my apologies). It is noted that the second mesocyclone was tornado warned by MAF/NWS as it enters Upton County, center of the concentric rings. While driving back toward Midland on FM 1788 in southern Midland county the advancing shelf cloud and accompany-ing gust front edge of the advancing squall line was captured. The next two images are, first, radar capture (clearer than previous) showing location of truck with respect to advancing gust front and second, a picture of the advancing shelf cloud. While traveling north on FM 1788 in central Midland county straight line winds estimated to be near 60 mph were encountered, blowing from west to east.

The author never observed a tornado from the primary chased mesocyclone (#1) and did not have an opportunity to witness mesocyclone(#2) for a long enough duration before encountering dark or obstruction of viewing angle to provide ground truth.

Abundant Low Level Moisture Leads to Afternoon Orographic Convection, July 4th, 2008, Near Terlingua,Texas

The following images were taken on July 4th in the southern Trans-Pecos geographic province of southwestern Texas at Terlingua (old cinnabar mining townsite, early 20th century). The first image captures early dawn, as viewed from the porch of La Pasada Milagro (Terlingua), looking east at Chisos mountains in background, and reveals "low-land elevation" fog where surface dew points from low level moisture advection are near or equal to ambient surface air temperatures which were cooled katabaticly by descending heavier air from higher topographic elevations.

Casa Grande Peak (exhumed volcanic intrusion) is seen at far right background. The next image is looking southeast from same locale at morning sun illuminating the Santa Elena limestone cliffs along Rio Grande river. The next image was taken in late afternoon at developing convection from orographic lifting which produced brief torrential rains and cloud to ground lightning. Mule Ear Peaks, southern extent of Chisos mountains, can been seen at left distant background and Santa Elena cliffs along Rio Grande are seen in distant center to right background. The final image, zoomed, portrays color contrast of Cretaceous claystones and siltstones (yellow) in foreground with purple/blue opaque rain core beneath Nimbocumulus, background. Visible Santa Elena limestone cliffs along the Rio Grande river are seen, right background, before becoming obscure a short time later.

Convective Initiation Along Quasi-Stationary Surface Front and Later Envigorated Forcing from Ensuing Outflow Boundaries, June 13th, 2008

Friday the 13th was not so unlucky for the Central Permian Basin as much needed moisture occurred due to the interplay of a trailing weak cold front, extending across the Permian Basin, from an intense Upper Level Low over the Midwest US and subsequent forced lifting from convective complex outflows. Thermodynamic parameters (not as impressive as the previous day where MLCAPE values were much higher and shear profiles stronger coupled with a sharper dryline) were not particularly impressive although a weaker capping inversion existed and if overcome development seemed probable. A Surface Low was located over the Davis Mountains, inducing convergence, and the upper air pattern was controlled by anti-cyclonic circulation centered in northern Mexico, south of Presidio, providing west-northwest to east-southeast wind directional shear aloft. Low level moisture was present, marginally, in the Central Permian Basin with surface dewpoints in the upper 40's to lower 50's, east of drier air in the western Permian Basin, additionally mid-level mositure was noted from water vapor imagery. At around 2300Z convection initiated along a quasi-stationary surface boundary, stalled cold front to slightly retreating warm front, southeast of Midland and extending along a transect from north central Crane to south central Howard counties. The first image is taken near the intersection of FM 1213 and FM 715, south of Midland, looking east northeast, at developing high based convective initiation in northwestern Glasscock county. The second image is looking southeast in southern Midland county at feeder inflow band and associated updraft of developing storm tower, followed by a zoomed image of same. Rapid intensifi-cation ensued, principally in south central Howard county, along the frontal boundary. Due to the high Lifting Condensation Level and subsequent evaporation of descending rain, a strong outflow boundary developed from the Howard county complex and began spreading southwestward toward Midland and Ector counties. This outflow boundary coupled with a now dominantly retreating warm front and impinged against drier air, west, (along dryline boundary) provided excellent lift into mid levels where lapse rates were steep. The next image is taken atop a multi-storied parking garage in downtown Midland at approximately 0200Z, looking northwest, at cloud to ground lightning from developing storm.

Discrete SuperCell Along Weak Surface Cold Front Surface Boundary, Reagan County, June 9th, 2008

Convective initiation began in late afternoon-early evening in the southeastern Permian Basin along and south of a weak surface cold front in moist lower levels and moderately unstable air aloft (MUCape values near 2000 J/kg), due to Upper Level amplified troughing to the north which when coupled with surface heating had eroded convective inhibition. All following images were taken from Midland looking southeast at developing storms, approximately 5o miles distant, in Reagan and Irion counties with a 70-300mm lens. The first image is zoomed at developing convective growth in Reagan county at approximately 0130Z. This cell became severe warned by NWS/MAF shortly afterward. Two additional images after warning occurred, noting crispness of intensification, (1) and overshooting top above vertical scalloped striations atop initial anvil spreading, (2). The next image is of a radar capture of the cell in Reagan county with well developed V-notch and also noting weaker cell in Irion county to the east of previous photographed storm. The next image is of the Irion county cell as viewed from behind, northwest, with back building convective towers. The next image is from the Reagan county cell, nearing dusk, showing hint of overshoot-ing top from main storm tower updraft above spreading anvil with back building smaller towers in foreground. The last capture is an un-zoomed image of the Reagan county cell during maturing stage.

Dry-Line Thunderstorms, Eastern Permian Basin, June 5th, 2008

Thunder-storms began to develop late afternoon early evening along a well defined dry-line in the eastern sector of the Permian Basin, along the southern said boundary, associated with an intense Upper Level Low centered in the central Rockies. The Upper Level Low and associated short wave troughs broke down an entrenched Upper-mid Level High which had controlled the weather across the Permian Basin for several days with above normal temperatures, exceeding the century mark. Low level moisture was present early in the morning and early afternoon hours, extending into the central Permian Basin but was gradually displaced eastward by strong westerly winds mixing downward from the base of the Upper Level Low, advancing from the western US. At 2000Z the author drove to Big Spring awaiting dry-line initiation where cumulus clouds had developed along the dry-line but mid level capping inversion was still in place preventing storm tower growth. The first image is a screen capture from the truck at previously mentioned locale depicting surface winds and defining dry-line with intersection of same and SPC depicting thunderstorm probability east of Midland. After watching the dry-line locale with cumulus cloud development for one hour, with no storm tower development, the author had to return to Midland. Later in the evening storm tower and organized cell development occurred. The next image was taken at 0115Z in a parking lot in Midland looking east-northeast at dry-line induced convection. The next image is a zoom of storm tower growth. The next image is radar capture of dry-line initiation represent-ing the previous photo-graphs delineating the northeast aligned, parallel to dry-moist boundary, eruption. The next image is a regional radar capture of storm develop-ment along dry-line with surface wind convergence overlay. The last image is a radar regional view of previous but showing 24,000 ft winds aloft, denoting 60 knot energy, rounding the southern periphery of the Upper Level Low overlapping with the surface to 850MB level dry-line boundary.

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.