The greatest sight on the afternoon of a chase; a huge towering cumulus on the horizon surrounded by blue sky. The storm developed very rapildy under a strong jet stream.
Extensive rain free updraft area on the southeast side of the storm. This cell became a large storm with a heavy rain core very quickly. Its initial motion was rapid to the northeast so I had to take what ever road was available to keep up.
The storm was was producing huge exploding towers over this rotating wall cloud. Laminar funnels were developing and dissipating. The ride across the lake atop the Glen Elder Dam was full of anxiety as the circulation spun overhead. Had I waited I would have been cutoff and gotten behind the briskly moving supercell.
This image was taken looking north as the wall cloud begin to consolidate. It was only about one quarter its original diameter. The smaller it got the faster it spun. I desperately needed a better angle on the storm. The contrast shooting into the hazy environment was poor and getting worse the further north the storm tracked.
Looking like it would drop a big tornado at any minute the wall
cloud spun violently up against the edge of the rain wall. I lost time during
this part of the chase as the dirt roads of northern Kansas were not conducive
to keep up with the storm. A Kansas Highway Patrol trooper was now pacing the
storm with me across Kansas farm roads.
While attempting to work back to US 81 the wall cloud continued to shrunk dramatically. If two important things are to be learned from this pursuit it's how a mesocyclone circulation can persist for hours while the wall cloud "spins down," or consolidates to about ten percent of its original diameter.
Now back on US 81 the shocker of the day came. A new convective base developing on the back of the storm quickly dropped a fairly large suction spot tornado. Shooting into the poor visibilities of this hazy day with a telephoto was not working though. I chose to not pursue this north moving feature and stay with my original circulation, although I was losing the race.
While traveling north through Hebron, Nebraska a tornado
finally began to form. I quickly executed a 180 degree turn and drove south
through town, then east on US 136. Now badly behind the storm I would do well
to capture the developing tornado. It was many miles to state highway 53, the
next road north.
Dry air from the RFD (rear flank down draft) continued to erode
the wall cloud circulation as it had done all day. The huge rotating wall
cloud, miles across at Lake Glen Elder was now only hundreds of meters across.
The forecast position of the low level jet was expected to parallel
highway 81 into Nebraska. Was this the final key to make this storm tornado?
The funnel came down painfully slow taking over 8 miles to hit the
ground.
I can't believe it; after four hours on a storm that took its sweet time doing anything, a tornado finally hit the ground. Unfortunately, I was driving for position during the best time of the debris cloud. A huge black cloud swirled around the base of the funnel as it totally wiped out a frame farm house down to the foundation. Also note that the wall cloud is now completely dissipated leaving a flat cloud base.
Out of roads and out of daylight I stopped to shoot into what remaining hazy twilight was available. The base of the tornado, listed as only 40 yards wide was one of the most violent I had seen. The tornado continued on as I watched it fade into the distance.
The tornado is listed as a Thayer Co. event, but it continued well into Jefferson Co. and was rated F-2.