Roger's SkyPix

The Majestic Supercell

Last Chance Supercell

Last Chance Supercell

A sculpted supercell is a remarkably common occurrence in late spring in the upslope flow regimes of northeast Colorado. Note the strong tilt to the storm, and the prominent downward bulge under the anvil at upper left, signifying still-moist convection in forced descent. Here, a small shaft of rain and hail is evident at the extreme right (NW) edge of the cloud base. The tapering inflow tail to the left (on the SE side of the storm) was part of a strong outflow boundary. This boundary helped the supercell form at the outflow/dryline intersection. But the outflow (from earlier storms, and reinforced by the circulation around an intensifying low to the southeast over KS) would eventually undercut and kill it. Low-mid level vertical shear and lift were both greatly enhanced at that "triple-point" boundary intersection, as is often true. That's why I favor triple-points for storm formation. In fact, no other storms developed in the area. At the time of this photo, the supercell had strong low-mid level rotation -- prompting a tornado warning based on Denver Doppler radar signatures -- but it produced no confirmed tornadoes.

5 S Last Chance CO (23 May 96) Looking SW