April 17, 2013

Wednesday, April 17, was shaping up to be the biggest chase event of the year thus far with a moderately unstable dryline/cold front triple point and great shear profiles. The forecast models had difficult with the setup, however, with large differences between the models on the cold front’s position. Less than 24 hour the different models varied by hundreds of miles on the front placement with the GFS putting it up in central Kansas and the NAM keeping down by the Red River, the RAP and and others somewhere in between. Still, the triple point play looked like it could be a tornado producer no matter where it wound up. Jennifer Brindley Ubl and I teamed up for this chase, and decided to take our time and get out there. We left the evening of the 15th, hoping for a modest warm front play in central Missouri along I-44 on the 16th, which was en route to our Oklahoma target on the 17th. The warm front didn’t make it much past the AR/MO border, and initiation looked sketchy at best. Not wanting to wait around, chasing in bad terrain, and then have to race west for the next day’s play, we opted out of chasing on the 16th and continued on toward our southwest OK target. We stopped in Chickasha the evening of the 16th, kicking it back at a Mexican restaurant where Mike Boik joined us for a Mapleton chase team reunion.

The next morning we took our time heading down to our initial target of Lawton, OK. We wanted to stay near the frontal boundary, which we hoped would result in a favorable storm interaction for tornadoes later. Initiation looked to occur to our southwest on the nose of a dryline bulge with the strongest surface heating and low level lapse rates right on the Red River into Texas. We pilfered some wifi at a hotel while setting up the cameras, before heading over to the Hop and Sack for some gas. A tornado watch was issued for the area and storm initiation looked imminent to our southwest, so we headed west out of town.

Just west of town we had our storm initiation, one due west of us right on the cold front and another coming off the dryline on the Red River. The cold front cell looked like it was just behind the boundary, so the southern cell, moving into unstable, uncapped air seemed like the obvious play. The northern storm organized more quickly and the radar indicated the boundary kinking into the storm’s inflow notch like it was roofing. There was a brief moment of hesitation at the highway crossroads west of Lawton before we decided to continue to the southern storm, which wound up being the right call as the northern storm gusted out into elevated junk behind the front not long afterwards. Brindley captured this radar grab with Spotter Network icons on her phone. With a moderate risk in Oklahoma, the roads would be packed with chasers we knew and we could already see them lining up on the map on the way out to the storms.

We got as close to the storm as the roads would allow before the grid ended near the Red River southwest of Frederick. It took quite some time for budding complex to organize into a supercell, the initial couple of cells being absorbed by new development to the southwest. By 3:30 the storm finally started to take off with a nice pendent shape on the radar. We got as far south as we could, a nice rain free base coming into view. Scud started to pull into the base and we had a developing wall cloud.

We had spotted a handful of chasers up until this point. As soon as the wall cloud started to form, however, it suddenly seemed like they were everywhere. Across the road, a truck parked in view of my camcorder while I was rolling time lapse of the wall cloud. Two women in cut off jean shorts and bikini tops got out of the truck while a guy attempted to photograph them doing poses in front of the wall cloud. A moment later, Reed Timmer’s Dominator whizzed past being followed by a large and unwieldy caravan, and finally a car with a chaser sitting on the window ledge of the passenger side door, shooting over the roof of the car while it was in motion. Brindley and I watched in dismay. This chase was going to be a three ring circus.

The wall cloud developed rapidly with an interesting point on the leading edge reaching down toward the ground. There did not appear to be much rotation, however, so I wouldn’t call it a funnel. The structure was looking very promising, however.

The wall cloud was moving northeast, and we didn’t want to fall behind, so jumped on the highway heading north. We didn’t want to use the unpaved grid at this point, seeing that it was wet from earlier storms, and we didn’t want to get stuck, or be forced into a slower pace with the wall cloud bearing down on us right on our heels. It was a bit of a race to get up to our next east road that was paved, but we beat the wall cloud which crossed behind us to the south without organizing much further.

We got well ahead of the storm and let it come to us, stopping just west of Frederick. The wall cloud dissipated and the rear flank filled in with rain, glowing with light behind it. It was a pretty sight, but the structure did not favor us for spotting tornadoes. We watched the storm for several minutes lettering approach while Brandon Sullivan, Mike Brady, and Brett Wright stopped to say hi.

We drove through Frederick and left the paved road heading onto the unpaved road grid to get closer to the inflow notch and away from most of the other chaser traffic.

Heading north to get in position on the storm, a new wall cloud with pronounced tail cloud started to developed. The storm was cycling and things were looking up.

We got into position to let the wall cloud mature and have the storm come to us. The wall cloud started to take on a bowl shape as it loomed over the red dirt road before us. It was the most photogenic supercell structure we had seen yet this year.

The bowl lowering tightened up with pronounced low level rotation. The chase was getting truly exciting now, and we had a great view.

Rotation in the wall cloud increased and a lobe on the southern end dipped toward the ground. It was the closest to a view of a tornado that we’d get.

We reposition northeast a couple miles stair stepping on the unpaved grid. The wall cloud was still dramatically structured, although the rear flank was starting to fill in a bit with rain. Another funnel like lowering beneath the wall cloud:

Panoramic view of the high precipitation supercell, with the rainy, donut shaped RFD core straight ahead:

Another panoramic of the supercell as the rear flank starts to fan out. We continued stair stepping until our unpaved grid met back up with a county highway. There were handfuls of other chasers on the dirt roads, but it was largely open. I feared that as soon as we hit pavement, however, the hordes would be back. Sure enough, as soon as we approached the highway, a radar truck passed by with an endless stream of headlights coming down the highway behind it. There were three vehicles already ahead of us waiting to turn or cross the highway and several more behind us. I knew we'd never make onto the road before the storm's core hit. I did a three point turn and turned around. We'd detour several miles south around the bustling highway intersection. It would cost us minutes on the storm, but the storm did not look like a tornado was imminent.

Our detour took us back toward Lawton, and rather than attempting to chase through the storm, we decided to get east of town and let it come to us where we could catch it over open terrain again. We had a few minutes before the storm would arrive so we decided to top off with gas. The sirens were wailing in town, and the gas station clerk came out to see us. We asked if she had shelter and she said yes. We advised her to head for it now. She only laughed and headed back into the gas station, however.

We headed north after getting gas to try and get into the inflow notch of the HP storm. The radar signature reminded us of our Henryville, IN chase a bit, with a big menacing hook echo, and another supercell with equally menacing hook right on its heals and slightly more south. We decided to play it like Henryville and chase the lead cell, finding an elevated position from which to view it, well downstream. Our road grid dead ended at an army base, so we couldn't go as far north as we wanted to, but we did find a great hill with view to the west.

Our view of the wall cloud several miles to our east was super low contrast. We couldn't make out any tornadoes like we did on our Henryville chase. We did spot a flash that appeared to eminate from the ground. A possible powerflash, and tornado? Other chasers reported it as such, but our view wasn't good enough to make a conclusive decision.

Wide angle of the RFD gust front overtaking Lawton:

We chased the storm northeast out of Lawton until it thoroughly gusted out with large wads of scud fanning out from the base. We double backed and made for the second cell in the line, which was still sporting a hook echo and tornado warning. We came in for the intercept just south of Lawton.

We began stair stepping on this storm as well. The structure looked quite a bit more ominous with a darker core.

Midlevel rotation was evident in the supercell, but there wasn't much of an attack point under the base to spot possible tornadoes and contrast was also quite low within the dark core. We stair stepped the storm around Lawton as we did the first storm, and it too started to gust out. Gremlins attacked the laptop and we lost GPS and data for awhile. With dusk setting in, the storm bearing down us, and with the stress of trying to reestablish data and navigation, Brindley and I decided to pull the plug on the chase. We took our next east road away from the storm to make our escape.

Night set in and we were hoping to drive several more hours to try and play the next day's target on the MS valley. The line of storms was passing by to our north, however, the cell just ahead of us still sporting a tornado warning. Without good data we decided to cool our nerves a bit and drop well south fo the storm and let pass by to the north, before attempting to cut through the line and start headng northeast toward home. Brindley and I sat on a dirt road watching the lightning illuminate some scud as the storm drifted past us. Once we were sure the most dangerous parts had pushed east, we headed up toward Chickasha and onto 44 toward OKC. A large squall line had formed, and not wanting to spend the entire drive home in it, we opted for the long route, heading up to Wichita, to KC, and then over to Saint Louis, instead of taking 44 all the way to Saint Lous. It was an extra 100 miles but spared us driving in the rain all night. The plan was to attempt an overnight drive back to central IL so we could get ahead of the storms for a play on the 18th. Brindley and I traded off driving through the night. By 6am, however, as passed Columbia, MO it was apparent that the squall line to our east was going to be the main show for the next day's chase, we weren't going to get ahead of it, and even if we did, we wouldn't have any energy left to chase it. We gave up and decided to get a room. The first place we stopped at, the Red Roof Inn in Columbia had the worst desk clerk I've ever encountered. We were an hour out from being able to check into a room with the next day's check out time, so she said we'd have to pay full price and would only get the room for 6 hours before check out. Fine. After fussing with the computer for a long time, she finally came back and told she didn't have the rooms she originally quoted us. We'd have to pay more money for their business rooms. We agreed and she continued fussing with the computer, eventually calling someone to try and help her. It was apparent at this point she had no idea on how to do her job, so instead of having her waste our time any further we walked out. We continued up the road to a Super 8, where the staff was super friendly, the room was actually cheaper, and they let us check out at whatever time we liked.