Full pictures and video up at
http://www.tornadocentral.com/chasing/2009/04262009.php (or on my Facebook profile).
Dan D., Robin T., Corey P., Mike F., Jen ., and I chased the lone tornadic supercell that tracked north of Roll, OK, this afternoon. We were originally hoping to initiation down near Childress since we liked the environment in southwestern OK and towards I40 best. On the way out west from OKC, we made a brief intercept on the cell that passed through Clinton in the early afternoon; that cell looked rather trashy after following it northeast of Clinton for 15-20 minutes, so we let it slide off and set our eyes back to the west. Noting initiation N of Wheeler, TX, we tredged towards Sweetwater, to the north of which we watched the cell take on some supercell characteristics. Road options aren't very good in that part of the state, so we had to trek all the way to Cheyenne to have an "ahead of storm" north option. At any rate, we made it through Roll, OK, after a very brief debate as to whether we should go east from Roll towards Leedey to get in better position of the storm or whether we should bite the bullet and drive northward to get a view of whatever was happening under the base. Fortunately, we were sick of being 10-20 miles SE of the storm, and we really wanted to get a good view of the base, so we chose the latter option. Several miles N of Roll, the tornado first came into view. The continued northward to get a bit closer to the tornado, which had the unfortunate side effect of not allowing me to take much in the way of (a) tripoded video or (B) decent still photography since I was driving (so holding the camcorder was the best I could do). This tornado (I guess it was #2 in previous reports -- we didn't see the first one) took on several different shapes, from a "dust cloud under a big bowl" to a nice stovepipe to an elephant trunk.
Since there were no east options until we got all the way up to Arnett, we opted to let the storm move away, setting our sites on renewed development N of Wheeler that was moving up towards Roll again. At one time, we saw a slender but easy-to-see funnel that extended nearly 1/2 of the way to the ground... On VNX and FDR, it looked like the funnel occurred where there was decent anticyclonic rotation -- the funnel did not appear to be related to the rain-free base or wall-cloud (where we'd expect cyclonically-rotating funnels). At any rate, we followed this storm up through Vici and N of Seiling, but it looked very wet and cold, particularly by the time it got to Vici. The Mesonet ob near Seiling was showing some cold northwest winds out ahead of the storm, which confirmed our visual obs of cold outflow pushing southeastward from the storm. Since the supercell seemed to be the southern anchor on the bow echo and squall line to its northeast, perhaps the cold outflow that pushed out ahead of the storm wasn't entirely from the supercell itself (i.e. perhaps it was actually outflow from the bow echo to the NE). At any rate, it was evident that the storm was not going to produce unless it got back into the warm sector, which didn't appear as though it was going to happen. At that point, we opted to call off the chase, essentially, though we kept our eyes open for the cells that were moving up S of Weatherford and El Reno.
Oh yeah, we also hit a calf / young cow that was standing in the middle of the Hwy 270 SE somewhere near Oakwood (between Watonga and Seiling). I saw a dark-colored animal (or person) walking on the right shoulder of Hwy 270... A northwest-moving truck passed me just before I caught a glimpse of a dark brown or black animal right on the yellow dividing line. With no time to avoid it, I hit it, at the full 65 mph. I thought it was a dog at first, but, after turning around to check it out, we saw one calf on the side of the road (where I saw it a minute before). A pick-up truck was pulled off on the shoulder, and the guy driving it said he hit a calf. We never found the calf that I (or we) must have time, since the calf that was on the shoulder was walking around. The only damage to my car was minor paint splintering on the bumper (presumably associated with the bumper flexing), which is quite remarkable given that we hit such an animal at 65 mph. We must have just nicked it with the extreme front-left side of my car... Night + occasional oncoming traffic (precluding me from using my high beams) + dark-colored animal in the middle of the road + passing a truck immediately before hitting the animal (always slightly blinding) = bad!
All in all, I'm certainly happy to have seen the "needle in the haystack" that was the Roll tornado. However, this has been a rather disappointing two-day chase outting considering >300 0-1km SRH both days. For whatever reason, we couldn't ever really avoid the myriad of cell interactions and mergers that we saw Sat and Sun, and the NE-SW orientation to the lines of convection the past two days probably didn't help the matter (in terms of cell interaction, splits, seeding, etc). If you told me that there'd be >1500 j/kg CAPE + 40-45 kt 0-6km shear + a dryline + >300 0-1km SRH, I would have expected much more.
Full pictures and video up at
http://www.tornadocentral.com/chasing/2009/04262009.php
