An area of low pressure was located over south central NE. on the morning of the 29th, and it redeveloped in SW NE. by the afternoon hours. Also by afternoon, an east/west aligned stationary front was in place along the CO./NE. border and across NE. A cold front surging southward from the northern plains also became stationary by that afternoon, and it extended into west NE. Strong surface convergence in between the two fronts would allow cells to fire by the afternoon hours, and with the extreme veering of winds, east at the surface turning to west at 250 mb, we thought supercells were a possibility. Everything south of the southernmost stationary front stayed capped throughout the day, but the weaker cap in the area between the two fronts allowed cells to begin firing by 3 p.m. near Scottsbluff, NE.
Scott and I left Wichita, KS. early and headed for our target area. By 4 p.m., we were heading west on I-80 and had just passed through North Platte, NE, and we soon began noticing some anvils off to our northwest. Just before 5 p.m., we took Hwy 26 northwest, and this route would allow us to get a good view of the updraft base on the southern storm.
At 5:30 p.m., we decided to set up on Hwy 26 about 12 miles north of Big Springs, NE. From this position, we had a great view of the cell that was moving ESE towards our position. We had a beautiful view of the cell, and I immediately began filming. By 5:45, another cell merged with the storm we were watching, and from our position, we watched a decent shelf cloud develop. During this time, several brief gustnadoes developed to the west of the main precip shaft, and we watched this amazing sight as each one formed and then dissipated while being pushed to the west by the storm's outflow. Unfortunately, also during this time, my still camera and tripod were blown over by a passing diesel and the focusing mechanism on the lens broke. After working on it for a bit, I finally got it working well enough so I could shoot some stills, but it was quite frustrating trying to focus the camera.
The storm continued advancing closer to our position, and near 6:30, a wall cloud was born when a piece of the shelf cloud disconnected and persisted under the updraft base for several minutes. At this point, we began losing contrast, se we decided to push east on Hwy. 26 and while getting into a position that would provide us with better contrast, Scott and I were blasted by dust being carried along by recorded 55 m.p.h. outflow winds. We promptly reported the wind speed to the office NWSFO in North Platte, and a severe warning for Kieth Co. was issued soon after.
We continued watching the storm get ingrained into an MCS as we pushed southeast on Hwy 26, and at 7 p.m., we decided to leave Hwy. 26 and use I-80 as our east route in our pursuit.
At 7:15, I began witnessing something that I had never seen before. The southern cell began to split away from the MCS and move SE across I-80. While this was going on, a cone funnel passed over the interstate, and a tornado warning was issued for the Tail End Charlie supercell. Once the meso passed into the field about one mile south of I-80 and our location near mile marker 168, a large and dust filled tornado formed at 7:55 p.m. The tornado quickly became shrouded in dust, and it's structure was no longer visible after about five minutes of being on the ground. The inflow into the tornado was quite strong, at least 60-70 m.p.h., and the inflow jet moving into the tornado from the west looked to have wind speeds of 90-100 m.p.h. It was quite a surreal moment to be standing outside of my car and filming a tornado that was no more than a mile away. Fortunately, the tornado stayed over open land and didn't do anything but pick up a wall of dust. At 8:01 p.m., the RFD became visible as it wrapped around the E and ENE portion of the meso and tornado, and the Hershey, NE. tornado dissipated soon after. During the time that tornado was taking place, we reported what was going on into the North Platte office.
Considering that the stationary front was located along I-80, it appears that once the storm crossed the boundary is the time that it turned tornadic. Supercells turning tornadic after crossing a boundary is something that Project VORTEX studied during their operation period, and boundaries seem to play a key role in tornadic development in some storms.
A new meso formed soon after the Hershey meso had occluded and dissipated and from 8:10-8:15, the new meso produced a few funnels and dust was rapidly being updrafted into the wall cloud. At this time, the North Platte office issued a special weather statement indicating that the radar was still showing signs of strong rotation within the storm and that a tornado warning remained in effect for the cell. Near 8:30, the cell began losing some of it's supercellular characteristics, so Scott and I decided to blast east and get ahead of the line of storms in order to get a look at what had to be an amazing shelf.
We weren't dissapointed when we finally got east of an incredible line of dust that was being kicked up by the outflow. From 9 p.m. to 9:35 p.m., we had a spectacular view of a major dust storm being pushed eastward ahead of the outflow and shelf cloud. The shelf cloud was quite spectacular as it exhibited a five layer structure, and the large wall of dust running ahead of it made for an eerie sight. It was something that I never in my wildest dreams ever imagined that I would get the chance to see, and here I was watching this wall of dust advancing towards my location at a speed of near 70 m.p.h.
After watching the beautiful storm structure from a few miles east of Grand Island, NE. until darkness, Scott and I decided to head back west from Aurora, NE. to Grand Island in order to get a room for the night. We were hoping that we would beat the advancing dust storm to Grand Island, but that was going to be a tough chore.
As we suspected, we got slammed by the outflow at 10:15 p.m., and a blinding dust storm ensued reducing visibility to zero. Once we plowed through the dust storm, we noticed that a couple of semis had been blown over by the intense outflow winds. Several people were already there helping the drivers, so we continued west, but I promptly called 911 and reported the overturned semis and a recorded 65 m.p.h. wind gust.
Upon arriving in Grand Island, we were treated to a beautiful lightning show as the weakening storms moved through the area. After getting a room for the night and eating dinner, we rested well after a long and rewarding chase day.