May 27, 2002 Crosbyton, TX supercells

Morning data revealed that a large area of west Texas into the Texas panhandle was subject to a significant supercell thunderstorm risk this day. Upper-air observations and short range model forecasts suggested that the core of strongest mid-tropospheric winds would be confined regions of west Texas south of the Panhandle while moderate southeasterly low-level flow, deep moisture and correspondingly high CAPE prevailed over the entire area. Finding and settling on a specific target storm would prove difficult this day due to the presence of numerous outflow boundaries, early convection and no clear overlap of strongest shear/instability/lift in one specific spot. Beginning the day in Midland, we blew off the boundary just north of town because I feared that the continuous plume of relatively hot/dry air from the south would result in high-based outflow dominant storms just north of the boundary. Had the deep-layer shear been a bit stronger and/or the time of year a bit earlier (and thus the deserts a bit cooler) that probably would've decided the issue. Instead we headed north to Lamesa, TX where another more subtle outflow boundary was visible in both satellite imagery and mesonet observations. However, I also worried greatly about storms that seemed certain to develop by mid-afternoon in the topographic storm machine that is the Texas caprock escarpment east and northeast of Lubbock. Once storms developed near Abernathy, we went in that direction, stopping numerous times between Lamesa and Lubbock due to indecisiveness about whether to stick with our original plan (wait for new storms developing between Midland and Lubbock) or see what the caprock could produce under moderate upslope and 25-35 kt mid-tropospheric winds. Finally we decided to go with the latter region. Arriving in Lubbock we headed northeast on Hwy 62. Looking over our shoulder, we saw a very strong convective explosion over Lamesa! We scurried to head back southward but stopped in our tracks when we looked northeast at the storm we were now leaving (near Ralls, TX - see second image below).

A noon CDT visible satellite image shows a myriad of convective complexes and associated outflow boundaries. Which to target or whether to target any of them? One sign of things to come is the cumulus field over the central Texas panhandle.	Heading back south on Loop 289 on the east side of Lubbock, we look to our east at the impressive supercell thunderstorm hovering on the edge of the caprock! We stop in our tracks and head east on F-M 835 to the east of Lubbock.	Once we get south of Ralls on Ranch 40 this is the view to our north. Note the scud finger slowly ascending into the base of a high-based updraft. The large storm-scale dry slot in the background is a feature typical of high-based outflow dominant supercells.	Driving east to follow the storm in the previous two images, we turn around and head quickly back to the west to target a new explosive updraft forming back near Ralls. Once we arrive south of Crosbyton on Ranch 651, this is the view to our west!
Note the tilted supercell updraft with fairly sharp-edged anvil. Inflow was strong and convergent just above the surface but we were experiencing cold northeasterly outflow air left over from previous storms.	The  rain-free base of the new Crosbyton supercell is producing numerous dusty spin-ups, doubtless occurring at the leading edge of the developing RFD. A lowering is forming on the updraft base's northern edge.	A close up of the RFD spin-ups and southern edge of the lowering.	The lowering at its most ominous. Very weak, ponderous differential motion can be seen within the lowering. However, I'm beginning to feel that the storm has developed in too cold a surface air mass to produce tornadoes.
The lowering and dust whirls persist in open fields southwest of Crosbyton.	The storm base with tapered flanking inflow tail with tour van in the foreground.	A radar display of the storm. It is the radar echo east of Lubbock with the "flying eagle" shape.	A precipitation shaft falls from the updraft's center.
The downdraft and associated precipitation, some of it in the form of very large hailstones, fans out at the ground forming an ominous "rain foot".	At the leading edge of the rain foot, one would experience very powerful straight line winds and damaging hail.	Another shot of the maelstrom occurring beneath the powerful supercell. It never manages to produce a tornado.