Chase Log: April 24th, 2006


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MAP
(ZOOMED)

Total Distance: 175 miles
Target Area: Kingfisher, OK
Chase Area: In and near El Reno, OK
Maximum SPC Risk category: Moderate
Watches: Tornado Watches 244 and 247, Severe Watch 246
Mesoscale Discussions (MCDs): 638, 640, 644, 645, 646, and 648

The models had been all over the place with the forecast for April 24th, but the general setup involved a surface low in western OK, with a strong cold front diving down the lee of the Rockies (with temps in the 30s in WY/CO/KS/NE during the afternoon). We were going to see (FINALLY!) real mid-upper 60 dewpoints into Oklahoma by afternoon! I was planning on chasing to the east and northeast of wherever the surface low was going to set up. Mid-level flow was strong enough to yield 40-50kt deeplayer shear, and CAPEs were anticipated to be near 4000 j/kg by afternoon. There was a peculiar weakness on the flow near 250mb (south at 20kts across central OK), but that wasn't going to be enough to keep me home, obviously.

I chased with Gabe, Dan, Robin, Howie, and others today. We sat in Kingfisher from about of hours this afternoon, watching storms develop near the OFB and cross into the cold outlfow near and east of I35. We were hoping somethign would develop west of Kingfisher and move eastward into the back flow near the OFB. Well, a few tried to go up after the initial round near 3pm, but these only acted to reinforce the cold pool. With only a very narrow axis of instability between the cold front / dryline and the cold outflow near I35 and the relative lack of sustained convection, we opted to drop southward towards a right-propagating supercell that was west of Anadarko. When we approached El Reno, radar was showing that the convection to the south was congealing into a quasi-linear mess, while another storm was exploding just southwest of El Reno. We sat just south of I40 for a while, watching the storm go from a flat cloud base to wallcloud to impressive RFD cut to tornado #1 to tornado #2... The position was nearly perfect, though we did have to shift south about half a mile in order to get some buildings out of the way. We followed this very slow-moving storm eastward after the first two tornadoes dissipated, but never really saw much else.

Overall, I am very pleased to have avenged the Oklahoma curse. I've really had very bad luck chasing in OK, so it was nice to get two very photogenic tornadoes. I haven't looked at my video, and I confused myself as to whether tornado #2 was anticyclonic or cyclonic... Since I accidentally left my camcorder on someone else's car as we got heavy wrap-around precip west of Yukon, I'm currently airing it out and crossing my fingers that it works. I'll have some pics up either later tonight or tomorrow. Yay to tornadoes within an hour of my apartment. The complete absense of precipitation in or near the RFD and tornadoes made the supercell look more LP than anything for a while.

04-24-2006 Chase Pictures

Click on any photo to see a larger version

This storm had some of the most impressive mammatus I've seen. Awesome color and definition. This wallcloud developed rather quickly... We had been watching the storm and it's rain-free base for about 10-15 minutes before this time (if I recall correctly). The RFD began to cut around the cyclonic mesocyclone at this time, as evidenced by the clear slot beginning to wrap around the low-level meso. The RFD continues to cut around the meso, and a nice funnel developed very near the middle of the larger-scale rotation. Speaking of the larger-scale rotation, it was very intense, and there was excellent rising motion along the right side. The funnel held aloft for a few minutes, before snaking down to the surface. Touchdown. The tornado was several miles to our west, so I couldn't get a good shot of the exact ground contact point. The clear slot was looking as though it was completely wrapping around the meso by this time. The funnel began to grow in size... This was about the maximum size that the tornado attained. Motion was pretty good, though nothing incredibly impressive. We were thinking that an east-northeast motion of of the tornado would allow it to pass just north of us. However, the tornado wasn't moving as quickly as I was expecting, so I doubt it got any closer than 4-5 miles from this position. I was also getting very worried that the tornado was going to directly impact the populated areas of El Reno. Fortunately, the tornado began to diminish in size (though not necessarily intensity!). Rotation remained relatively strong, but again, not entirely breath-taking. Buildings to the WNW began to block the near-surface portions of the tornado condensation funnel. That cow obviously hasn't had any spotter training yet... I was trying to point out that the tornado was on his LEFT... The tornado narrowed to a pencil-shape, and strong downward motion was evident on descending scud near the tornado (associated with the RFD).The translucent / semi-transparent nature of the lowest part of the condensation funnel was neat. The color and back-lighting made for a very photogenic tornado. In addition, there was no precipition to be seen near the RFD or tornado. Same image as the previous, just in BW (obviously). While the first tornado was dissipating, we noticed a second funnel developing and dropping from the cloud-base to the south of the RFD. Not long after, a small, mostly-transparent dust tube extended from the funnel to the ground. Tornado #2. The second tornado formed right where we would expect to see an anticyclonic tornado -- just to the south (right from a storm-relative perpsective) of the RFD. I believe this marks the 3rd anticylonic tornado that I've seen in less than 2 years. The first tornado was still on the ground, and the (very thin) tornado condensation funnel can be seen on the right. Again, the color and backlight was very nice, and the lack of any wrap-around precipitation made photographing the tornado very easy. The condensational funnel was one of the thinnest I've ever seen for a tornado. The southern tornado was a beauty! Not only was it anticylonic, but the lighting and shape was incredible. The tornado looked to be sliding slowly to the east or southeast. The tornado slowly spun down in time, and the dust began to settle as downward motion characterized the periphery of the tornado. I believe these mammatus clouds were eminating from a storm southwest of Moore. Regardless, with the setting sun casting orange light, the mammatus were quite photogenic. You can see the updraft tower from that storm to our southeast, but that small row of low clouds block most of it.

04-24-2006 Chase Video

Click the photo or description to view the video

El Reno Timelapse 1 (~8MB WMV) El Reno Tornado (~18MB WMV)