Chasing a family of EF4 tornadoes, including the devastating Pilger twins
The tornado event that unfolded in northeast Nebraska on June 16 2014 was a once-in-a-lifetime experience for storm chasers and, sadly, tragic for the people in and around the town of Pilger. That morning we woke up in Omaha after chasing southwest of there the day before, knowing that this day had the potential to produce significant tornadoes. SPC issued a moderate risk for northeast Nebraska, southeast South Dakota, and all of northern Iowa, and the morning air was muggy and hot. I had us wake early, wanting to play around with the mid-morning severe storms that would be rolling through, before spending the afternoon chasing the more serious stuff. We had a quick breakfast at 8:00, and were out the door shortly thereafter.
Within an hour, an isolated storm went up west of the city and soon became a supercell. Wanting to avoid city roads and traffic, we positioned on a hilltop just to the east of Omaha and let the storm come to us. It was truly beautiful, a great big mothership, looming over the horizon. We followed the storm eastward a little ways into Iowa until it began to fall apart, then abandoned it to prepare for the next round that was to come.
At 1630z, SPC upgraded their moderate risk to include a 15% hatched area for tornadoes in northeast Nebraska. Although there was still some question as to whether the morning convection would stabilize the atmosphere back that way and prevent storms to form, clearing was rapidly underway and this was looking like less and less of a concern. It was apparent that any storms that could form there and interact with outflow boundaries from the morning storms would have the potential to produce violent tornadoes. We settled on a target of Norfolk and set off in that direction.
We crossed into Nebraska near the town of Onawa, Iowa, just as the first blips began to appear on radar right over our target. Within ten or fifteen minutes, these little showers were exploding into what would be come the storm of the day. We blasted westward as our storm became a supercell; within a few more minutes, the first tornado warning was issued. By the time we reached Wisner, reports were coming of a cone tornado on the ground. Soon, reports indicated that the tornado was a large and extremely dangerous wedge, very close to the town of Stanton. We were approaching the base of the storm and, occasionally, thought we caught glimpses of the wedge in the distance. However, just as we passed north of Pilger, I took a quick look at velocities and realized we had to stop immediately; another tornado was forming just to southwest of that town.
I had Mike turn us around to face eastward and pullover, and there to our south was large cone funnel extending halfway to the ground. “There it is, there’s our funnel!” I called out as we got our first glimpse of what would become a destructive and deadly monster.
The tornado initiated as a raised cone with multiple vortices dancing below, but soon consolidated into a large stovepipe as it approached Pilger. To our south, the water tower, tree and roof tops of town were dwarfed by the looming tornado. We continued eastward to stay ahead of it, now with a sense of dread, knowing that the Pilger would take a direct hit. As the tornado sliced directly through the center of town, we noticed a second funnel forming ahead of it to the east, so now we raced to stay ahead of both.
A swirl of debris appeared beneath the new funnel and we now had two tornadoes on the ground. I assumed that this was a satellite tornado that would be brief, a not-so-uncommon occurrence alongside strong or violent tornadoes; I was wrong. This was the beginning of an exceptionally rare – if not unheard of event; within minutes, we had two powerful EF4, cone tornadoes travelling side by side. To our southwest, the first tornado filled with debris as it cut through and devastated town; to our south, the second tornado quickly became a violent multiple vortex and became tossing debris into the air as it tore apart a rural farm. Taken totally by surprise by the intensity of this second tornado, we now had to move quickly to get out of its way. We raced east to get completely out from beneath the mesocyclone, and stopped at a gas station to watch as the two tornadoes crossed the highway behind us.
Once the pair of tornadoes crossed the highway, we travelled briefly east and then north to stay with them. Now tracking them to their south, for the next half hour we watched in awe as the pair of tornadoes raked the countryside. As they moved northeast, they each widened into fat stovepipes (borderline wedges), backlit silhouettes on the horizon. Southwest of the town of Pender, the second tornado rotated around the first and dissipated. The first continued on, but began to enter its rope stage west of town. As it was roping out, a new bowled lowering developed and touched down as another large multiple vortex. The first tornado, the one that struck Pilger, finally dissipated as it whipped around and was absorbed into the circulation of the new tornado. This was the beginning of the fourth EF4 tornado of the day, which would go on to ravage farms east of the town of Wakefield.