CENTRAL NEBRASKA — Two supercell thunderstorms produced five tornadoes, one of which was rated EF-3, across south central Nebraska during the afternoon hours of Friday, April 26.
Synoptically, a tightly wound upper level and surface area of low pressure was moving across Nebraska during the morning hours and its associated forcing would go on to produce the supercells across central Nebraska.
“Supercells which produce more than one tornado are usually called cyclic supercells, as when a supercell forms more than one tornado, it is deemed to have “cycled” through the lifecycle of each tornado,” the National Weather Service – Hastings stated in its public information statement.
The tornadoes in the NWS Hastings coverage area were confined to Buffalo, Sherman, Howard and Greeley counties.
The first tornado of the day started near the ethanol plant east of Ravenna, where minor damage occurred on a catwalk.
The tornado moved north-northwest during its life cycle and crossed from Buffalo into Sherman County.
The most significant damage was at a residence in southern Sherman County, where outbuildings were damaged or destroyed.
The Ravenna tornado was rated EF-1 with an estimated peak wind speed of 90 mph based upon damage to a power pole and structures. It lasted from 12:16 p.m. to 12:31 p.m.
It was on the ground for 4.7 miles and its maximum width was 175 yards. The tornado faded away on or very near State Highway 68 about three miles north of Ravenna in Sherman county, per NWS Hastings.
The same supercell would spawn a second tornado in Sherman County, south of Rockville. It was sighted in a field and then moved north across the Middle Loup River.
The tornado caused EF-1 rated damage to a home and damaged outbuildings just south of town.
This tornado moved north along the east edge of Rockville and went on to damage trees, several grain bins and outbuildings. It continued to move north roughly along the Rockville Road and snapped power poles.
Based upon reports, the tornado likely dissipated in open country about four miles north of the town.
The Rockville EF-1 had peak winds rated at 105 mph, its maximum width was 100 yards and it was on the ground for 5.7 miles lasting from 12:32 p.m. to 12:48 p.m.
The tornado that would cause damage in Elba started initially as a narrow funnel south of Farwell based on eyewitness reports, but would eventually strengthen into a large, wedge-like EF-3 tornado.
This tornado moved across rural areas of Farwell, causing tree damage and overturning several central irrigation pivot systems. The tornado emerged onto the North Loup River Valley, west of Elba and gained significant strength, per NWS Hastings.
“Just west of Elba, a farmstead sustained heavy damage to a home, outbuildings and vehicles, among other items. A well built metal building structure was demolished along with extensive damage to the nearby farm home,” the NWS Hastings damage survey noted.
The tornado was estimated to be 600 yards wide as it crossed Highway 11 just northwest of Elba. A long stretch of power poles were knocked down along Odell Road.The tornado would eventually navigate across the North Loup River, 2.5 miles north of town.
By this point the tornado had moved into pasture ground and based on radar data, the tornado likely weakened as it moved north, however, it would start the process for the next tornado that formed to its east.
The Elba tornado was rated EF-3 with peak wind speeds of 145 mph, it covered 9.5 miles from 12:58 p.m. to 1:21 p.m.
During a 10 minute process, the supercell did not advance much and a fourth tornado formed in northern Howard County, which would grow into the widest tornado, at least half a mile wide at times.
The tornado started five miles northeast of Elba and was eventually rated EF-2, with estimated peak wind speeds of 135 mph based on metal power pole damage just west of the Highway 281 and Highway 22 junction near Wolbach.
“The tornado had previously destroyed a metal building to the southwest, and would go on to destroy a couple of wood framed outbuildings to the northeast of Highway 281. The south edge of the tornado likely passed just north of the Highway 281 and 22 intersection,” the NWS Hastings damage survey noted.
It was in this general area that the tornado was at least half a mile or 880 yards wide.
The tornado would continue northeast causing damage to one residence, outbuildings, trees and center irrigation pivots.
“As the supercell slowed down north of Wolbach, this tornado likely diminished, the damage noted was much less severe and sparse, and the supercell began a process of developing another tornado to the east, likely similar to the process described previously,” NWS Hastings noted.
The Wolbach EF-2 was on the ground for nearly 10 miles from 1:32 p.m. to 1:54 p.m.
The Wolbach/Primrose tornado started about four miles northeast of Wolbach and was associated with a parent supercell that had previously produced two other tornadoes.
“In Greeley County damage was confined to mostly center irrigation pivot systems and trees. The tornado moved northeast mostly over open country and crossed the Boone County line along Highway 56,” NWS Hastings noted.
In Boone County, the tornado caused minor damage to a home on a farmstead at the county line along with a notable amount of tree damage in the general area.
“The tornado moved north and appeared to strengthen some as it flipped and tossed several center irrigation pivot systems north of Highway 56. Power poles were snapped and debris was lifted into power lines,” NWS Hastings noted.
As the tornado moved north-northeast, the most significant damage was found about two miles southwest of Primrose.
“A single-family home was extensively damaged, including the three-car garage being totally ripped away along with much of the roof structure. Several outbuildings were damaged or destroyed. Extensive tree damage and numerous power poles were snapped in the area. Tree damage was widespread west of Primrose and one large outbuilding was destroyed,” NWS Hastings stated.
In its final few miles, the tornado damaged trees and center pivot irrigation systems in several places.
“Extensive damage to a livestock facility and several snapped power poles was noted about halfway between Petersburg and Primrose. The tornado likely dissipated in open country as it approached the Beaver Creek southwest of Petersburg,” NWS Hastings said.
“The widest point of the tornado appeared to occur just to the west and southwest Primrose when the tornado may have been at least 500 yards wide. The EF-2 rating and estimated maximum wind speed of 130 mph was based upon the damage that occurred at the home southwest of Primrose,” NWS Hastings stated.
This tornado started in Greeley County and was on the ground for over one hour along its 27.5 mile path.
“The staff of NWS Hastings would like to thank local Emergency Management and residents for their invaluable help conducting the surveys,” NWS Hastings noted.