May 10 was a well forecast and hyped event that ended up panning out as advertised. A compact 50mb trough was forecast to eject quickly through the southern plains during the evening with rapid low level moisture return beginning May 9th into the 10th. Deep moisture had spread over much of the warm sector in Oklahoma and southern Kansas by midday Monday with upper 60’s dewpoints present. Deep layer shear was more than sufficient for supercells and strong low level shear suggested tornadoes were a good bet with any storms from near the sfc low in KS down the dryline through much of Oklahoma. The morning of the 10th my dad and I ventured north of OKC a bit to wait and see how things would develop. We were eyeing the north central part of OK where an instability axis was pointing in towards and 0-1km shear was a bit better for early in the day. The HRRR model runs were consistent with development in north central Oklahoma as well earlier in the day. With 50kt storm motions, we decided to go for this northern target thinking it would be in better chasing terrain and road network than points further south and we could stay out of the metro areas near OKC (which ended up getting hit late in the day). We made our way into Enid at roughly 2pm to watch some growing cumulus in northern Dewey Co. These storms quickly became severe tracking northeast towards Alfalfa Co. We made our way towards Nash OK where we got our first view then continued north out of Nash heading for Sand Creek. By this time our storms was tornado warned and exhibiting strong mid level rotation but seemed a bit high based and still needed some time. By the time we reached SR11 southwest of Sand Creek, we watched as the storms quickly developed a RFD cut and displayed rapid cyclonic motion. Soon a small tornado rotated out of the side of the mesocyclone just west of us.
(All video stills, got some good video)
As it lifted we jumped east on SR11 with the storm developing extreme rotation over our heads as it raced east at nearly 50kts. I got my first view of a developing multiple vortex tornado out my window south of the road as it began tossing debris from trees into the air then turned into a large multiple vortex tornado a couple hundred yards behind us. I filmed out the back window as most of this was happening with my dad driving east stuck in heavy chaser convergence. Small vortices would dance around the main circulation from time to time while the storm was doing damage.
Once we got east a bit, we watched as the once rain wrapped tornado cleared out and the tornado had a stout appearance just south of Wakita, OK.
We continued east towards I-35 and decided to leave this storm due to motions and rain wrapping around the meso. Next we dropped south to the next supercell which was producing a tornado east of Billings but we could not see it from the north and a core punch didn’t sound too good with baseball hail falling. We pulled into a gas station near Billings to take a look at the hail damage.
Meanwhile, more storms had been forming near the OKC metro and back home around Norman. We opted to drop south and try to get ahead of these in eastern OK but that never worked with the hills, trees, and road network. I was on the phone with Cassie most of the day who was on campus in Norman and had to take shelter because of the tornado that tracked in south Norman along highway 9 doing substantial damage. Overall, a tough but successful chase with storm motions and a major outbreak for the state.