April 24, 2015

Brindley and I were originally watching Friday, April 24 for a dryline play in southeast KS/eastern OK. As the event approached, however, the setup morphed into a split target between the warm front/dryline triple point off the low in Kansas and what looked to be an outflow boundary/dryline triple point in north central Texas. We were also slated to be part of Sean Casey’s crew for the season, chasing in the Doghouse with the Tornado Intercept Vehicle. This trip was to be our first time meeting up with the group for the season. We left the day before, stopping in Tulsa for the night, which we thought would be a good midway point to hit any target along the dryline. The 12z numerical forecast models, however, were now indicating a target on either I-70 or I-20 and nothing in between. We were at a deadlock for which one to go after, and we had to make up our minds immediately as, at 9am, we’d just barely have enough to make it to either target by what we were hoping would be a 4pm initiation. The TIV crew was down in Ardmore, OK planning on meeting up with us in OKC in the morning. The KS target had better lapse rates, and was closer to the surface low, but the TX target had better moisture, cape, and upper level flow. We finally relented to the Texas target, mainly because the following days’ setups looked to in Texas as well and it would save us a whole bunch of driving. We were rolling before 10, which turned out to be a too late given the distance we had to go. The TIV went for the Texas target as well, not waiting for us.

Heading down to Texas with a little bell pepper and bean dip snack.

We clipped a sub severe bowing complex coming into the north side of Fort Worth. The trailing outflow boundary from the complex would be our source of lift and enhanced directional shear for afternoon supercells.

Gust front from approaching line of storms north of Fort Worth:

The cap was open for business, however, and storms fired before 2pm, way earlier than we had hoped. The lead cell in a small cluster quickly blossomed into a big supercell and went tornado warned before we could even make it to our 4pm initiation/intercept point. Traffic on I-20 west out of Fort Worth was excruciating with pokey truck drivers in the left lane and long lines of cars.

We got off of I-20 heading south toward Rising Star. The 75 mph speed limit on the two lane county ighways made for a much faster approach than on the traffic heavy I-20. A thick inflow band leading into the murky, rain obscured updraft base came into view as we headed south.

A tornado report came in on the storm. We gritted our teeth trying to get down there, hoping we hadn't missed the show. The blue green core and low clouds feeding into a tornado warned supercell:

We turned west in Rising Star, the traffic briefly piling up at the four way stop in the center of town. Heading west for the intercept, a high precipitation RFD gust front came into view. The terrain was less than ideal with some hills and trees and no road grid off the highway. There were perches with views every couple of miles, however, and we kept going until we found one within the supercell's inflow notch, just a couple miles short of Cross Plains. Heavy precipitiation obscured our view of much of the RFD region, but we could see rapid motion in the scud feeding into the base on the far rim of the mesocyclone, deep within the inflow notch. We had just a couple minutes to watch, as the northeast moving storm was about to cross our highway and we'd have to move east to get out of the way. We hoped for a glimpse of a tornado within that brief moment as we stared into the notch, but we saw only HP storm structure.

There was a fire somewhere to our southwest. The brown smoke started to get pulled into the updraft base as the storm approached.

We finally had to turn east and head away from the approaching RFD gust front, just ahead of a line of cars, most of them likely storm chasers. Looking south at the apex of the RFD gust front:

Heading back into Rising Star, I incorrectly guessed that we had time to gas up, as we were getting down to less than a quarter tank and were now preparing for a long chase running east ahead of an HP. The TIV passed while we gassed up. I watched the core approaching from the west. It didn't seem like it, but it was inbound at 50 mph. I cut the gas stop short as the core approached and traffic was lining up at the four way stop in town. We jumped into the line, frustrated that there was so much traffic trying to go every direction at the stop. I again incorrectly judged that we had time to get south of the RFD and toward a trailing storm that looked more promising. My radar scan was old and I had misjudged the orientation of the storm, however. The apex of the bowing RFD had already crossed our south highway. I pulled a u-turn and we headed back toward the four way stop, skidding to a stop and making a sharp right to go east, just as the streaky bands of rain in the RFD core started to envelope us from the southwest. "The Fast and Furious: Rising Star Drift".

We headed southwest out of Rising Star in the blasting wind and rain of the bowing RFD core, eventually coming out of the stouh end of the storm. The roads in central Texas make a criss crossing grid of diagonals. We had no way to keep up with what was now a fast east moving storm. The 70 knot 500 mb winds were pushing the storm east at almost 50 mph. We could only go southeast away from the storm with every northeast option leading back into the core of the storm.

We stair stepped diagonally until we were finally in line with the southern end of what was now a gusting out severe warned complex. We decided to run northeast for one last intercept attempt before the complex moved into the DFW metro area, knowing that we still wouldn't beat the core as it moved east of us. A huge and surging Whale's Mouth came into view as we approached Rio Vista from the southwest.

We stopped shy of the precipitiation core to watch the chruning and turbulent mass above us. To our surprise, the town sounded its sirens, even though the whale's mouth structure suggested to me that the tornado threat was minimal over our location.

Somebody from a nearby school drove up on an ATV to ask us about the storm before retreating for shelter.

We hung around until the rain finally hit before we called it a chase and started heading toward Weatherford where the TIV crew was stopping for the night. We grabbed dinner at the Chilis under clear, balmy skies before we met up with Sean, Justin, Herb, and Peyton at the hotel.