One more McLean chase entry
This day was one of the greateat catches since my storm chase hobby began in the late 70's (early 80's on the plains). I met Charles Edwards in Yukon, Ok. where he promptly threw his gear in my truck, hooked up his laptop which had the latest GR level 3 software installed.. and we merrily hit the road westbound on I-40 in hopes of at least seeing a good storm with some lightning, I knew the chances were there that tornadoes would be present somewhere within a hundred miles of us, but being it was February, and minimal chances of daylight convection... I expected to just see a couple of good storms and get into the mindset that chase season was close at hand.
We decided on Shamrock, TX.. many others had thought of Childress and with moisture advecting northward and slighly warmer temps, that target was reasonable. We decided on Shamrock thinking that cells would fire first somewhere near Clarendon and race northeast where we would intercept them. Besides, the 18 and 21Z RUC both broke out convection a little below I-40 west of Mclean, so we thought that going west was as good as any place to point toward. As expected, we went through about 60 miles of a stratus field with occasional wind whipped drizzle, we broke into clearer conditions west of Sayre, we stopped at Erick around 1615, where we examined the latest data, satellite photo's indicated bubbling Cu and congestus all across the eastern PH of TX. with an enhanced area of convection near Clarendon which quickly showed returns on radar, I figured it wasn't surface based but within a few scans was exhibiting 40+dbz returns just north of Clarendon moving hastily to the northeast.
The chase now on, we saw the first convection just west of Shamrock, I wasn't too enthusiastic over the cells as they were soft with glaciated tops. these storms were of multicelluar nature, but as we proceeded west, a couple of these storms had some crisp updrafts. We made it to Mclean Tx. just past 1700cst where we watched several of these storms graze our location. We became pretty excited when the first storm just passed us around 1720 and had a very pronounced mesocyclone with scud clouds screaming into its updraft. Winds backed as this cell just missed us, gusting to around 35mph, some very small hail fell with moderate rain, most of which came from the anvil. CG's were occasional with one close bolt about 3-4mi. away.
Then, the next cell came up from the SSW.. the radar indicated a meso with this as with the last one, so we went a little west of town by a couple of miles where we sat as this cell did virtually the same as before, a spattering of rain, winds would back almost to the east.. 20-30mph, and "graupel" sized hail. Within literally a minute, the rain stopped. and we could see the base with attendant meso to our west.. there was no lowering, I could see little rotation, but there was a pronounced clear slot, cloud base was flat and about 1700-2000ft. agl .. Charles remarked there was rotation, but at that moment to me, it was insignificant. I thought about blowing off this cell and heading back toward Shamrock to intercept the next in the string of pearls gracefully spinning there way across the prairies. As I was about to turn around, I noticed a small area of chaotic motion in the cloud base just north of the clear slot. We started watching that, it immediately developed a bowl shaped lowering... well alrighty then, I thought, the cynical part of me saying this won't last long and it would bait us in staying there as we would miss something to our south.
The next ten minutes commencing at 1800cst, my jaw would hit the ground as moments after the bowl shaped lowering happened, it developed a perfectly tapered funnel that within a minute skipped across the ground from about 7mi. or so west of McLean to about 10mi. to the north. This funnel which was a fat pencil shaped vortex for the most part continued and developed a classic dry slot. The contrast was great and the video I took was for the most part, steady. At times, I zoomed in close revealing the swirling condensation eddies at its base and as it made contact with the ground. Other times, I zoomed out exposing the entire updraft and dryslot. It definitely was a chase for the books... and February! and a mere one day before my birthday... a fine present indeed.
We quickly went back east after the funnel disapated, hoping to intercept the next cell to our south. As it turned out, alot of these storms temporarly weakened at sunset, and the show was over for us and I was faced with a barrage of phone calls from fellow chasers and... media outlets that got wind of what I caught (!!)
Below is a link courtesy of Charles Edwards and Cloud 9 of his video he took and pictures.
http://www.cloud9tours.com/bear/2007/index.html for pictures
http://www.cloud9tours.com/video/McLean.html for video
Rocky&family