North Texas Outflow Redux
17 Apr 7
SHORT: Outflow dominant storms with occasionally photogenic shelf clouds between Albany-Strawn, missed seeing Haslet spinup despite being right there. Nice sunset.
LONG:
I had small but nonzero hope of catching a discrete and photogenic storm before too many formed, and perhaps getting a tornadic needle in the haystack of storms over northwest and north-central TX. Instability would be the major problem, especially in a boundary layer that had sloppy, cool trajectories from a partially modified continental air mass instead of more richly moist origins from the deep Gulf. But I also had the day off, the blessing of my beautiful bride to head out, and no pressing obligations at home.
By the time I got to Seymour, where I grabbed my first two Allsups burritos of the season, it was apparent many storms already had formed W-SW-SSW of me. The 53 deg F surface temp with north winds wasn’t too encouraging either, but perhaps something of interest could snatch a ribbon of favorable surface-based inflow from some marginally heated air down near ABI and SJT. I finally broke out of the cold drizzle and slop between Throckmorton and Albany, and could see what appeared to be a lowered, surface-based inflow base off to my SW. This SE-surging cold air soon would undercut it, but I kept one eye peeled for spin-ups before that happened, the other eye scouting for a safe pull-off, and the third trained on the road itself (just kidding!).
Actually, every time I go down 283 between Throckmorton and Albany, it gets more and more frustrating, The road is a twisty ribbon, slow to drive safely when wet, and the thick mesquite forest seems to get taller and block more of the western sky every passing year. By the time I found a good stopping point N of Albany, the base indeed had been undercut.
Another base to the more distant SSW jutted E from what was becoming apparent as a line of storms, but both I and the updrafts struggled to stay ahead of the cold surge. By the time I got in decent proximity, that next base (between Albany and Moran) got undercut also.
By now the mode of the day was quite obvious, and I didn’t want to go racing S of I-20 for more of the same. Instead I decided to cut my losses and head E on the interstate, stopping as warranted for any decent shelf or gust front scenes. There actually were a few, especially in the Ranger/Strawn area. I stopped at the TX-16 overpass to watch the dark plow of static stability advance my way through the cut tablelands. The scene becomes even more eerie or menacing when doing some selective composition, looking directly down the interstate (horizontal view and zoomed vertical). I decided to bail the scene and head home via FTW when the edge of the outflow got to me and the inner chamber of the shelf’s band shell could be seen off to the SW.
Along the way I spotted a few chasers, but not the usual big crowds. One garishly custom-painted truck along I-20 (near Ranger) sported the words “STORM CHASER” in cartoonish, foot-high letters down both port and starboard, sweeping back horizontally then diagonally upward from amidships to stern. Given all the trouble between storm chasers and law enforcement in some areas lately, it’s probably not wise to so brazenly and immodestly declare oneself as such for the world to see! Oh well, if they want to blow a big stack of coins on that paint job and risk whatever happens as a result, so be it.
Yes, I see the report of a brief/weak Haslet tornado in the day’s rough log. I was driving right by Alliance Airport and just E of Haslet when the storm line moved in, yet didn’t see it, but I also wasn’t staring westward every second for a possible spinup. The whole arcus front looked like a fuzzier, colder and more featureless version of the Strawn shelf cloud above, but I guess one never can rule out a gust-front spinup or kink of some sort. The Metroplex seems to have a way with odd little vortices this year.
A highlight of the trip actually was the pretty sunset near Marietta, enjoyed while listening to a stereo chorus of eastern meadowlarks and downing a delicious Andes mint shake (from the Jack in the Box down in Sanger).
Dark Storms and Outflow W of the Metroplex
Filed under: Summary
13 April 2007
I decided to roll the dice and go for the area of more questionable lift — but higher-end/long-lived tornado potential given a storm — E of the front/dryline, instead of playing the questionable (for moisture return reasons) triple point region. When you gamble, sometimes you get snake eyes, but I’m OK with that in a storm observing sense.
The trip down gave encouraging signs as the car thermometer slowly rose from the upper 40s in AbNorman to the upper 60s by the time I got S of DAL. It had the look and feel of a classical warm frontal tornado day, just insert discrete storm. I got to the library at Ennis and, the Seymour storm well out of reach, waited for signs of development to my W and SW. When that didn’t appear, I became quite concerned that the only show was going to be on the frontal surge. Finally, a clump of Cu and Tcu SW of MWL gave me some hope that a discrete storm might form and interact with the front before being plowed by cold air, so off I went in that direction. Of course, the risk of outflow dominance characteristic of such a regime played out.
Gassing up in Weatherford, I noticed the low clouds had cleared (warm FROPA!) and a big anvil W-N. BC informed me this was indeed Tail-End Charlie and a likely HP supercell. By the time I was NW of Weatherford, traveling toward Whitt, the anchor storm near MWL was tor-warned near Graford and headed E directly for where I was. I pulled off near Whitt to watch a dark, outflow-dominant mass move my way (looking WNW toward the warned area — a meso apparently lurked somewhere behind that mess — and looking SW). I didn’t stay long because this was charging E at 40-45 mph and I needed to get back SW through Weatherford to stay ahead.
Even though I’m not a big fan of cold outflow, I’ve had a fondness for mean, dark, menacing storm colors as long as I can remember. This had just such a presentation, and I couldn’t help but stop quickly one more time near Peaster to take in the experience for a minute and to get a shot of the foreboding aura of doom.
On this date, I had no traffic problems of consequence on both passes through Dallas of the one around the S side of FTW (deliberately avoiding the dinner hour). Instead the worst such experiences were in Weatherford, and in the little dot on the map known as Cresson!
It took me 25 minutes to get through Weatherford on the second pass, and meanwhile, the outflow and rain overtook me. It had been several years since I drove through there and I couldn’t remember exactly why I didn’t like it. It soon came back to me: The traffic circle around the courthouse. That’s common in Texas towns, and normally either no problem or a minor nuisance. Here, however, there are two lanes in the circle, and if entering in the right lane, you need to change lanes to stay on the same route (i.e., not make a right turn). Worst, on each of the four entries is a stoplight unsynchronized with the others. Especially on the second pass, with a dark storm moving in and cars stacking up from every direction, it was an absolute zoo, a dead standstill or slow crawl.
I want to know what sadistic idiot designed that, and what brand of glue the town fathers were sniffing before the meeting where they approved it!
The country drive between Weatherford and Cresson was really pleasant, even under a shelf cloud, and almost devoid of traffic. BC informed me about the tornadic storm that apparently had broken away from the line (my old Whitt circulation or some derivative thereof?), and become tornadic over FTW. Geez, I thought, there’s no way I’m going to get through traffic to get ahead of that…I’m scr_wed. Further plotting revealed my only shot was to go around the S side through Midlothian/Ennis again and hope something was left of it over by Kaufman and Ray Hubbard.
Then, HALT! About 3/4 mile from the US 377 crossroad, a stack of brake lights as far as the eye could see over the hill and through the dale. A wreck? I thought so, given stop-and-crawl movement that seemed comparable to the average rate of fingernail growth. After about 15 minutes I saw the problem: a single stoplight with (by now) well over a mile of vehicles behind it on FM 171. This is out in the country too, not in any developed areas. The light turned green every 3-4 minutes, lasting only long enough to let perhaps 6-8 cars through at a time, and only one or two vehicles if they were hauling trailers.
I did make it past the bluebonnet fields and over to Kaufman, but barely behind the storm. A quick dinner and an uneventful drive home through Dallas followed.
Despite the traffic problems outside the immediate DFW area, the drive itself was very enjoyable, with bluebonnets blanketing numerous fields between Kaufman, Ennis, Midlothian and Cresson. The land, gently rolling meadows of the tree-dotted blackland prairie is so refreshingly green now after a few years of drought-ridden dessication.
Thanks to bc, Elke and Steve C for their calls and helpful info! Except for the triple-point storm, linear convective mode and lack of lift ahead of the cold front (in the warm sector) were the primary failure modes for the prior outlook of discrete, long-lived tornadic potential.
HP Supercell in the Borderlands
30 Mar 7 Storm Intercept near Del Rio
With a few days off in prime bluebonnet season, Elke and I had been planning a trip to central Texas and the Hill Country for some photography, German food in Fredericksburg, and true Texas barbecue in Llano. Storm potential intervened, and conveniently enough, near the southern edge of the area where we were going to be anyway!
After my freakishly productive storm chase of 28 March, I got the windshield replaced the next morning, and Elke and I made it as far S as Temple (TPL) for the night before exhaustion set in. Despite the potential for a lot of heavy rainfall overnight and the next day, we were confident that favorable shear would extend far enough south that some decent storm observing potential might occur across the blackland prairies between Temple and San Antonio (SAT), or even more probable, the flatlands SW of the Alamo City toward the Rio Grande and Del Rio (DRT). I only had chased in those parts once before, a promising supercell potential turned into a junky squall line near Hondo (HDO) on 12 May 97, so I was eager to do better on this nearly 10-year return interval.
We were packing to leave our motel and finishing breakfast in TPL, when I logged on for data and — lo and behold — a tornado warning already was out for a supercell not too far SW of us, in the Hill Country just west of Austin (AUS). With waffle crumbs still riddling my shirt, it was too damned early in the day for this!
I wasn’t confident the storm would survive long, moving into rain-cooled air N of the latitude of AUS; but if the effective warm front were to retreat northward fast enough to keep up, the storm’s right motion would take it across the Goergetown/Round Rock area toward Taylor or Granger. We chose to avoid the I-35 mess and headed S on TX 95 to Taylor. The storm died before getting out of the hills, so we proceeded through several driving rainstorms E of AUS, caught I-35 at San Marcos and headed around the N side of SAT. Another supercell — at the west end of one of our rain-piles — apparently produced a couple brief tornadoes in the rugged terrain of northern Comal and Hays Counties N of SAT, but we weren’t about to try chasing in deeply forested, steep hills under conditions of driving rain and likely flash flooding.
Instead we headed out to HDO to look at data in the library there, hoping for favorable clearing and late afternoon destabilization farther S and W. While there, a clump of storms formed NW of DRT and near the Rio Grande, around Comstock, along a meridionally aligned convergence line that extended N from the Serranias del Burro range in Mexico. This was our target! Its projected path would take any resulting supercell along the southern edge of the hills, and in an area of scant roads N of US 90, so we knew any views would be transient.
We broke into clearing skies just E of Brackettville, seeing the big Cb off to our NW over the mesquite scrublands. Driving by the radar site there reminded me of the “Radar Muncher” supercell several years ago that delivered a brutal, roundhouse right to the radome. During a fuel stop in Brackettville, we heard a tornado warning for the storm near Comstock. I was both concerned it would cross US 277 N of DRT before we could get there (it did), and hopeful that Gene Moore was out there and could sample it N of DRT (he was). I charted a course up FM 3008/2523, the first N option E of DRT, hoping the storm wouldn’t be too deep into the hills.
Meanwhile, N of DRT, Gene saw a funnel behind some precip and an increasingly outflow dominant, HP storm which became a mean-ugly-nasty (MUN), butt-munching HP by the time we could arrive. We headed N through a Border Patrol check point (how often does that happen on a chase?) and stopped somewhere in the canyonlands S of Carta Valley. It was hard to get a decent view due to increasingly rugged terrain with northward extent, and Elke was spooked by the dark storm clouds rolling in and the prospect of flash flooding. So we wisely backed southward several miles and let the storm roll by to our N (another shot).
The meso was buried in darkness and precip on the NE side of a surging, cold gust front. Seldom have I ever known such storms to recover any sort of classical structure after such an outflow-driven, HP transition. Considering that, and the hills and sparse roads in its projected path, we decided to say adios, tormenta! We stopped on an overlook to watch the storm retreat into the murk to our NE and ENE, while listening to a joyous chorus of bird song (including some gobbling wild turkeys) in the rain-cooled, earthy smelling semi-desert air.
The storm itself churned along toward the ESE as a big HP “kidney bean,” battering the bush with hail up to 3 inches in diameter. I certainly didn’t need any more of that action given my brand new windshield glass!
While grabbing a wi-fi connection in DRT, a pickup parked next to us belonging to a business with a rather interesting name. Dinner in DRT was quick, to give us time to head N of town to shoot sunset cloudscapes and look for damage (none found). The golden rays nicely illuminated a tower to our E, forming in the elevated warm advection regime atop the cold outflow pool (zoom lens shot of a “lobster tail” convective plume).
A new line of storms to our W-N (early shot of tail-end Charlie) provided an intermittent lightning show on the way to Rocksprings, where we hoped to get a room for the night, but also gave us concern about renewed flash flooding over US 377. We saw strandlines from receded high water caused by the big HP, but fortunately, no floods blocked our path. Unfortunately, we hit some big rocks in the road, washed there by earlier flash floods, and I got a slow tire leak. We made it to Rocksprings before I had to use the Fix-a-Flat, and got the tire repaired there the next morning in order to resume our Hill Country vacation.
The bluebonnets are out in force! The “prickly poppies” and purple phlox are in full bloom as well, and the Indian paintbrush was just getting started (that should be erupting by now, as I type this). I hope to post some pix to my BLOG soon…ITMT if you have a chance to get down to central TX in the next couple weeks, please do. It’s a splendid show of bounteous floral grandeur.