The Valparaiso University Storm Intercept Team had their sights set on this day because any easterly winds would be channeled around the Palmer Divide (central CO) and the Front Range of the Rockies, creating a large-scale wind tunnel known as the Denver Convergence Vorticity Zone. This has long been studied as it seems to be tied with spinning up supercells and tornadoes in the area; this day was no exception. Early on, around 2:00pm MDT, a supercell was born near the Front Range, and this was our target until we crossed its path near Bennett, CO. One thing that made this day incredible was its thick, soupy atmosphere. Colorado, usually dry with crisp, blue skies, was as moist and humid as the midwest in July and swarming with mosquitoes. The appearance of the storm we encountered was no different, a soupy mess with extremely low cloud bases:
The storm appeared to be gusting out and becoming outflow dominant, so we hesitated staying much longer and instead looked toward a new cluster of developing cells to the east.
The cloud bases were amazingly low.
As we depart, it begins to show some interesting spinning motions.
The new cluster of storms was explosively developing. It took a long while to punch through them while they continued to intensify, and by the time we had escaped the first it became tornado warned. Three dominant cells had taken over; this one on the NW side near Cope, CO, another on the SW side and a third on the SE side.
This one was in an atmosphere worked over by the others, but that didn’t stop it from producing a fickle tornado that touched down multiple different times near Cope, each taking on a different shape.
First a brief rope.
This attempt was much stronger.
Finally, the tornado lifted for many long minutes, only to crash back down large and bowl-shaped.
Multiple vortices can be scene near just above the horizon.
Even though highly rain-wrapped, the storm had a textbook clear slot wrapping around into the tornado, with sunlight trying to stream in. The tornado quickly took on a more cone-like appearance.
A thick inflow band fed into the tornado as it hauled onward.
We were a very safe distance from this storm. Though we had quite a sight on the ground already, the SE cell near Vona, CO was moving into air untouched by other storms and showing signs of producing one of its own. We left this scene and fled south, straight through its core as the circulation approached. A tornado was confirmed, rain-wrapped and invisible at the time, but we continued as we were quickly gaining ground and would soon be in safe position.
As soon as we cleared the rain to view the storm, a new circulation developed and immediately dropped a small funnel just a half mile away.
I thank the right-hand passenger-seater for excusing my desperate reach.
Once again, classic clear-slot structure and horseshoe shaped base twisting into the funnel.
The funnel quickly dissipated and whirled into the massive rotating base of the storm, seen on the center right third of the photo. From this point on it was difficult to tell what was technically a tornado and what was not, as both small vortices and large wedges carouseled around each other.
This chaser obviously was not close enough.
As soon as the first vortex lifted, another formed to the left.
The motions in this storm can really be seen as this lowering literally looks tangled around itself as it decides where to connect to the ground next. After this ambiguous tornado headed east, we attempted to pursue it until we realized it was quickly becoming wrapped in rain. We left this storm, knowing we probably would never get this close to a tornado again, or at least not for a long while.