Green Sky Chaser

22 April 2010 Chase Log


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Target Area: Childress to Clarendon/Silverton, Texas

Chase Area: Childress/Clarendon, Texas to Hollis, Oklahoma

Observations: one tornado, two or three funnel clouds, four or five wall clouds, two supercells, hail, lightning, and a rainbow

Distance: 580 miles

Time: 13.5 hours

Chase Team: Jeff Makowski and myself

SPC Convective Outlook: Slight Risk (upgraded to Moderate) (Click to see SPC products, data, and storm reports)

Chase Setup: Large trough/closed low moving over the Southwest with associated surface cyclone over southeastern Colorado. A dryline extended south of the low into the Texas Panhandle (with a cold front behind it), while a warm front extended through central Kansas. CAPE of over 2000 J kg-1 in the southeast Texas Panhandle (model verified well). Dewpoints ahead of the dryline in the lower 60s in the east Texas Panhandle. Winds backing south of the warm front and along the dryline (winds were from the southeast in the southeast Texas Panhandle, likely from morning convection...the model forecast winds to be more from the south...). Strongest wind shear mostly near the warm front, but also decent ahead of the dryline. Supercells expected along the dryline in the Texas Panhandle, with some large hail and possibly a few tornadoes. (Another point of concern was the triple point, near the low; in the end, there were more tornadoes up north, but most of them were more rain-wrapped.)

Blog Entries:

Chase #4 (before)

Chase #4 Evaluation (after)

Chase Log: After some debate over whether or not to drive north or south, or even down I-40 and split the difference, we decided to stick with the southern target. Shear may not have looked quite as impressive, but CAPE and moisture were better, CINH and cloud cover was less, and we thought we'd rather chase more isolated storms in the Panhandle than messy storms in Kansas. In the end, both target areas verified; the one in southwest Kansas, and the one in the southeast Texas Panhandle (there were also tornadoes near the low in southeast Colorado).

We took a chance and committed to the southern target, driving on I-44. Once we got to Lawton, we drove west on Highway 62. When we arrived at the border, there wasn't much to see other than some stratocumulus clouds, but we proceeded south on Highway 83 to our initial target of Childress.

We stopped in Childress for a little while, debating what to do while trying to get a better wireless signal. We saw a storm or two forming to our north, but they were closer to I-40 and we didn't have time to get there. The storms also looked less impressive visually than on radar; I thought they looked too sheared, and did not have solid updrafts.

Eventually we decided to drive northwest on Highway 287 towards Clarendon. Almost as soon as we left Childress, we saw a beautiful storm form right in front us. Knowing that it was in a better environment, especially seeing as how the surface winds were more from the southeast than expected, we opted to go with this storm.

As we approached the slow-moving storm, we began to see a lowering underneath the cloud base. Before we knew it, we had a rapidly rotating wall cloud on our hands. In fact, as we looked to the south, we saw another supercell with another wall cloud. Somewhere around this point we ran into a lot of other chasers.

Sandwiched between two supercells, our attention was primarily focused on the storm to the north. It appeared more mature on radar, and it looked like it was rotating much faster than the storm to the south. We stopped northwest of Ashtola to watch the first storm for a while, before the wall cloud became obscured in the rain. At this point, I noticed that the storm to our southwest had a wall cloud and was headed straight for us! We decided we had better back up a bit, as there was also some rotation nearly straight overhead.

Almost no sooner did we get back in the car and drive a couple miles towards Ashtola, than a beautiful funnel cloud touched down behind us. I stopped the car, and we got out and watched the full life of the tornado, from about 5:20 to 5:40 pm. The tornado went through several stages, including what appeared to be a cone, barrel, stovepipe, elephant trunk, and rope. Dark against the sunlit sky and cumulus behind it, this tornado was one of the most beautiful tornadoes I have ever seen. This was Jeff's first tornado, and it was definitely one of my favorites.

Although I wanted to get closer, as the tornado approached Highway 287, we stayed where we were (just couldn't stop taking pictures and video!), around 5 miles away (closer to 10 miles at its farthest). The tornado was later ranked EF1, one of the strongest of the day; fortunately it only hit a couple of power poles as it crossed the road.

The northern supercell, in the meantime, produced about six short-lived, weak, rain-wrapped tornadoes. We never did see any of these other tornadoes, but we didn't regret our decision to stay with the southern storm. We did follow the storms northward on Highway 70, but didn't see much else of note. On the way back to Oklahoma, we saw some lightning from the northern part of a supercell near Childress, as it was producing a couple of large tornadoes (didn't produce much damage).


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