Monday, April 25, 2011
Chase Report for 2011 April 24: Tornado near Baird, Texas
Bob Fritchie and I observed the first tornado north of Baird, Texas around 3:30 pm. We followed the storm 90 minutes before we turned back west for the next storm in the line, but missed the second and third tornadoes of the day, also very near Baird.
In the early afternoon it seemed a surface low and weak triple point had formed south-southwest of Abilene. This was indicated in the surface observations, and the cu field evident by 17z showed what appeared to be an outflow boundary from previous convection draped along the interstate. With stronger midlevel flow than any previous setup in this regime, I assumed that if even half the RUC-forecasted CAPE was realized, the storms should be more intense than the last two days. When I left Denton, I planned to stop at Graham, but this setup and the RUC / HRRR convergence on the solution compelled me to to go much farther west. I only hoped I wasn’t too late.
I met Bob in Graham and he agreed. This target jived with his forecast from two nights ago. Soon a small shower formed near Abilene and we turned south at Throckmorten to check it out, though we held little hope for this initial cell since winds at ABI were northerly, and in the prior few rounds of obs, the surface low had become ill-defined.
Five miles north of Baird, we noticed elevated rotation in an otherwise unimpressive, almost HP-ish base. But soon this tightened up—just south of another large and rotating wallcloud. The rotation near us gathered rainbands and a clear slot cut behind the circulation. Moments later, a lowering descended, a funnel pointed straight down. It rotated a long time before fully condensing and then stretched and curved, attached to the back of the meso—the back of the entire storm, actually, like a tail. Behind it were clear skies. In the field ahead, the circulation barreled through the grassland.
After the tornado we dropped south and east to race out ahead of the storm. It developed several more wallclouds until it was clear the boundary magic was in the past. We turned back west for another storm approaching Baird, which also produced tornadoes almost in the same spot as ours, but these appeared before we regained sight of the notch. We followed that one also, another hour or so, before a third turn back west ended unsuccessfully.
We finally headed home around 8:00 PM, met with Denton chasers Robert Hall, Mike Mezeul II and his friends, for Italian food at Pasta Fina in Weatherford. Bob mentioned to me in a text a moment ago how much fun it was to see tornadogenesis at very close range in such detail. He’s right. Quite a spectacular phenomenon.
Sunday, April 24, 2011
I observed initiation of the “Gainesville storm” this afternoon when it was east of Sunset, Texas. I followed it on the north side toward Forestburg and saw a significant lowering on the flanking line, which included some weak rotation. I let the storm core pass north over me thinking I could stay on the southeastern flank, but as it intensified the updraft was farther and farther away. Finally I dropped south and turned east on FM 922 and there I saw the first of many large, threatening wall clouds. FM 51 was the perfect northeastward option and along the way I stopped two see two distinct wall clouds, both rapidly rotating, and the southern one seemed all but destined to produce a tornado—but it didn’t.
In Gainesville the larger circulation took dominance and while the storm hovered above the city I came into the backside of the hook region for a white-light view of another large funnel, again rotating impressively. I followed the storm through the city and on State Road 82, about ten miles east of town, saw another large funnel shaped lowering, this one more shrouded in rain.
With convection from the south interfering with the storm’s inflow region, and it’s trajectory toward northeast Texas and the Red River Valley, I turned back for another storm, this one with a tornado-warning near Decatur. When I reached this cell about a mile northeast of Decatur, it was mostly outflow-dominant and produced some interesting fingers along the gust front. Here I met up with Daniel Shaw and Jimmy Deguera, both from Australia, and we returned to Denton for dinner at Sweetwater.
Saturday, April 23, 2011
Chase Report for 22 April 2011
Australian chaser Daniel Shaw and I left Denton at 20z with plans to wait in Gainesville, Texas until it was clear whether to continue north or go west. My plan was to catch the “tail-end Charlie” storm (if one appeared) west of Gainesville because I assumed it would have a longer residence in favorable terrain. I thought the embedded supercells within the squall line farther north would move into the “jungle” of southeastern Oklahoma, where I’ve never had fun chasing. As it turned out, one of those embedded mesos produced a tornado near Byers, Oklahoma.
About 6:00 PM, both targets lit up. Daniel and I headed west and our supercell came together just north of Wichita Falls after suffering two splits and three mergers, the result of the weak low level flow, which probably made the difference later between a tornado and no tornado. In addition our storm was relatively high-based until late that night. Our dewpoint depressions never fell below 15F.
We gained sight of the updraft base around Henrietta and turned north to maintain position. Right away it was clear the storm enjoyed strong instability, from the sharpness and beveled appeared of the anvil, but suffered from a lack of ventilation, as rain descended through the updraft. The resulting cold pool would probably kill our tornado chances, I expected, unless the storm moved into a more favorable shear environment. However, this combination made the cell into an efficient hail producer, with 1” to 1.5” stones routine in the core.
Near Petrolia, Texas, I noticed another merger on the southeastern flank. I thought we should hustle down there and see if a new updraft region might produce something of interest, and as we moved south and east, some elevated rotation began to our south.
When we emerged from the core about five miles north of Henrietta, on SR 148, dramatic wrapping rain curtains crossed the road to our immediate south and when we stopped we had a weakly rotating wall cloud with a blood-red sun for backdrop. It would have made for a spectacular tornado shot—the whole reason I wanted to stay in favorable terrain—but it wasn’t meant to happen.
As the mesocyclone crossed the road, the lowering was bathed in white. A warm, dry RFD swung around and felt refreshing compared to the sauna of the warm sector. We stayed quite a while shooting the anvil crawler lightning that snaked between the red-tinged mammatus.
Friday, April 22, 2011
Thursday, April 21, 2011
Colin Davis, an excellent young writer and chaser at Knox College in west central Illinois.
Monday, April 18, 2011
2011 April 8 in North Central Oklahoma
In Norman, I met up with Bob and Rachael Fritchie and we elected to go north after considering southwest Oklahoma briefly. Decided it was much too hot down there, with extreme dewpoint depressions all but eliminating the chance for tornadoes. I hoped we could get on or near the boundary in northern Oklahoma. We wound up meeting Tony Laubach and Scott Currens somewhere between Kingfisher and Hennessey. The storm rapidly evolved into a decently structured classic supercell and produced a rotating wallcloud which descended so quickly that Bob and I began preparing to shoot the tornado. Scott and Tony played in the core and found some large hail. But our tornado didn't happen. It appeared as if the RFD destroyed the circulation as the entire appendage separated from the cloud base soon after the failed t-genesis effort. My guess is that relatively low RH air was the culprit. Storms farther north on the boundary did produce tornadoes later on. Sad indeed. Later our storm morphed into a fine mothership style cell with KH waves around the crown.
Later we all met in Stillwater to eat at Eskimo Joe's, a fun way to wrap up the night.
Earlier in the chase, 2011 April 8.
Next day, 2011 April 9 in Kansas.
The next day, while seemingly all of Chaser Nation was 'bagging the phat tubes' in Iowa, I moped around central Kansas looking for something to do. A busy workweek ahead, including a fiction reading out of town, prevented me from venturing north of I-70. The cap was fairly stout and I thought I'd busted for sure when at last a series of small, non-severe storms fired in southwest-central Kansas. This one erupted near Greensburg and was photogenic enough for me to retrieve the camera. Later that night I met up with Dan Dawson, Robin Tanamachi, Jeff and Kim Snyder, Gabe Garfield, and other friends of theirs for dinner and great 2 meter QSO on the long drive home. Made it back to Denton around 4:30 am.
But I chased on April 8th and 9th. On the 8th we followed a storm from Enid to Red Rock that assumed a variety of shapes and modes and nearly produced a tornado, despite the highly unfavorable RH environment and weak low level shear. I have plenty of photos to post. The next day I was solo and restricted to chasing south of I-70 (work considerations), and assumed I'd busted until a crisp little storm erupted near Greensburg late in the day and gave me something to do.
Photos coming soon! The best part was all the old friends I met again and reconnected with, the long list soon forthcoming. A chance for chase ops this weekend has me excited that my preferred places west of I-35 might see action.
I suppose this blog will become more active now. I realized a few days ago that few chase blogs are older than this one, in continuous service for eight years running.
Saturday, April 09, 2011
Fun chase this afternoon from near Enid to Red Rock, Oklahoma, on a long-lived supercell that produced a massive, rotating lowering (but alas no touchdown), great striated structures, KH waves around the crown (likes of which I hadn't seen since 2 June 2005 with Eric Nguyen [who would've loved this day]), and a torrent of medium to giant sized hail, which Scott Currens and Tony Laubach happily intercepted and documented as we all get into the swing of the upcoming HAIL project (more on this later).
Bob and Rachel Fritchie, Scott Currens, and Tony Laubach caravaned all day. Met up with Jeff Snyder and Gabe Garfield, two great, young chaser-scientists, and a new Met at OUN named Mark. We finished the day in Stillwater with a big heart attack dinner at Eskimo Joe's, a delicious suggestion from Rachel.
I'll post photos when I'm back home and have some extra time.