5/29/2012 - COD Trip 3 Day 5

On Tuesday, we targeted northwest Oklahoma. As we drove north from Wichita Falls, TX, a cu field northwest of Watonga, OK appeared on satellite in this target area. Sure enough, convective initiation occurred in this vicinity. We watched the southern storm develop and struggle for a while to become dominant. The storm had a rather narrow and high base initially, but was very slow moving. Soon, the storm turned hard right and dove southeast, getting into a better thermodynamic environ. As such, the base improved and became wider.  Shortly after, we felt the meso become established as inflow kicked up and maintained itself. Midlevel features became very prolific and pretty -- sort of upside-down wedding cake/stack of plates appearance. The storm then began to go through several RFD cycles, at times producing exciting lowerings with lots of cloud base action/rotation. Twice, RFD’s produced some dust plumes under cloud base, but we could not determine if they were rotating, but both were in locations that they had to be associated with outflow bits of vorticity. At least a few times, anti-cyclonic rotation was evident on the near side of an RFD or two.  All-the-while, we had a left split racing north, set to merge with our storm. Storm then went into mothership/cinnamon roll mode near Piedmont and Tor’d. We are unclear whether or not left split may have simply aided thermodynamic properties of the inflow to our storm, or if more dynamic processes were at work to help produce the tor. However, it appeared that the RFD managed to do it on its own. We plan to do a thorough review of the level 2 radar data if we can find some down time.  Because of new supercellular development to the west-northwest of our storm and massive chaser convergence, we decided to drop well south and try to flank new development from the west. We stopped just before the on ramp to 44 south from SR4; we had heard reports of a tor in the closest of the new developing supercells. Some in the group saw the tor between flashes from rather far. We opted to hang there for a while and take lightning pictures. We then hopped on 44 south to outrun outflow.  In Chickasha, we stopped again for pictures briefly after noticing power flashes that were produced by RFD outflow. A few more pictures, then ended chase and had dinner at Braums. 44 north to hotel in OKC. [Evan Anderson contributed to the text]