A surprise EF-2 tornado ripped through Tulsa, Oklahoma early Sunday, August 6, 2017, destroying buildings and injuring 26 people, two of them severely. The National Weather Service confirmed two EF-1 tornadoes in towns nearby. Tornadoes in August are uncommon, but not 'outrageously rare,' NWS said.
NWS Tulsa Meteorologists surveyed several tornadoes that developed early Sunday morning as a bow echo within a quasi-linear convective system (QLCS) moved through northeastern Oklahoma.
The strongest was rated as EF-2. It had maximum estimated wind speed between 193 and 209 km/h (120 and 130 mph), and was on the ground for 6 minutes, from 01:19 CDT to 01:25 CDT. Its path length was 11 km (6.9 miles) and maximum path width 503 m (550 yards).
This tornado developed along the leading edge of the bow echo, over a neighborhood east of S. Harvard Ave. and south of E. 36th St. S., where large tree limbs were snapped and homes were damaged, NWS said.
The tornado moved east-southeast crossing S. Yale Ave. where numerous trees and power poles were snapped. Numerous businesses were damaged or destroyed between S. Yale Ave. and S. Sheridan Road along and within a few blocks of E. 41st St. S. Some of the worse damage in the path was in this area.
Some of the businesses in the area had the roofs blown off the structure and some had exterior walls blown down. Several vehicles were rolled in this area, and reportedly about 26 injuries occurred here. Numerous other businesses sustained mainly roof, wall, and window damage between S. Sheridan Road and Highway 169. Many power poles and trees were also blown down in this area. The tornado turned more easterly near Highway 169 and moved roughly along E. 51st. St. S., dissipating just before reaching N. Aspen. Ave. (S. 145th East Ave.).
The survey team found additional tree damage east of N. Aspen Ave. near Battle Creek Golf Course, but this damage was much more broad and lacked the pattern of debris that was typical of the tornado further west.
The storm left 11 000 customers without power at one point. More than 9 000 remained without electricity Sunday morning.
The interstate was closed for a short period of time due to a fallen sign on the highway.
National Weather Service meteorologist Amy Jankowski said tornadoes are generally associated with spring months and said an August tornado is uncommon, but not "outrageously rare."
The second tornado, rated EF-1, touched down 01:27 CDT, 4.5 km (2.8 miles) north of Broken Arrow. It developed over a neighborhood along and north of E. 51st St. S. and west of S. 177th East Ave. where numerous homes received damage to their roofs and trees were damaged. The tornado moved east-southeast uprooting trees and snapping large tree limbs between Lynn Lane and County Line Road. The roof of an outbuilding was blown off on County Line Road.
It had maximum winds between 145 and 161 km/h (90 and 100 mph) and was on the ground for 4 minutes. Its path length was 4.7 km (2.9 miles) and maximum path width 366 m (400 yards).
The third tornado, also rated EF-1, touched down 01:32 CDT 1.6 km (1 mile) east of Oologah and dissipated 01:40 CDT 2.4 km (1.5 miles) SSE of Talala. Its path length was 7.2 km (4.5 miles) and maximum path width 183 m (200 yards). It had maximum winds between 145 and 161 km/h (90 and 100 mph).
This tornado developed east of Oologah where barns and trees were damaged, NWS said. The tornado moved northward along the S. 4110 Road where power poles were snapped, a home was damaged, and trees were blown down. The tornado turned more northwesterly after crossing the E. 370 Road and dissipated south of the E. 350 Road. There were no injuries.
According to CBS, there were signs of the first tornado on the radar but sirens never went off because the NWS did not issue a tornado warning until after the twister had moved on.
Roger Jolliff, director of the Tulsa Emergency Management agency, said they did not sound the sirens because the twister had already moved on to the neighboring city by the time the National Weather Service issued its warning. "I said if it's in Broken Arrow, we will not sound our sirens because the threat at that time that we had got this information... was going into Broken Arrow," Jolliff said.
The National Weather Service said they used two different radars to follow the storm system, and when the closer radar showed the tornado on the ground, they issued the tornado warning.
The officials CBS spoke with said they would be reviewing what happened in this situation. Tulsa's mayor says after the cleanup is done, the city will also review its technology and protocols for initiating tornado sirens.
Featured image: Damage after EF-2 tornado rips through Tulsa, Oklahoma on August 6, 2017