Friday, April 8, 2011, was my first true Oklahoma storm chase. The day had looked promising all through the week as the spring's first classic dryline setup over central Oklahoma. However, when I went to bed Thursday night, the Storm Prediction Center still had only a slight risk of severe storms in the area. During my programming lab Friday morning, the slight risk area was removed except for a sliver of north-central to northeast Oklahoma up through Kansas and Missouri. In no mood to drive that far, I held out hope for the dryline to the west on the 10% or worse chance that it might produce an isolated storm. I loaded up the car (camera, tripod, atlas, weather radio, etc.), picked up my friend Tim from his class, and cruised northwest up to the OKC suburb of Mustang. Tim is a freshman from Pittsburgh who, like me, was drawn over a thousand miles from home for days just like these. In a Taco Mayo in Mustang, we mulled over our options, and based on a mesoscale discussion from the SPC that suggested possible convective initiation off to our southwest near Lawton, took off down OK-4 to Tuttle, where we picked up OK-92 toward Chickasha. We ended up stopping by a railroad crossing in the town of Amber, on the edge of a vast green wheat field.
Watching the southeast wind send ripples through the field was certainly entrancing but lost its intrigue after an hour or so; line after line of towering cumulus failed to break the cap. More and more short-range models and other chasers' thoughts pointed us farther north toward OKC, so we left our spot late in the afternoon and retraced our steps north. As we approached Yukon, a tornado watch went out for a swath of the state from roughly our position up to the central Kansas border--and storms were already exploding south of Enid.
With no other choice, we took I-40 east into downtown OKC to hit I-35 north, and we made the trip through town smoothly in spite of rush hour traffic. As we raced north, huge anvils overspread the sky. After about an hour, we approached the town of Perry. Leaving the interstate, we stopped for a few gallons of gas, photographed some mammatus over Perry, and headed east on US-64 to parallel the main storm at the time. It had split, and the northern split was going tornadic, but the south storm was in our way and still presented a mediocre chase target with lightning and mammatus. We turned north on US-177 and stopped twice for unimpressive photos, and the storm died out in front of us.
Forcing ourselves to be content with a nice drive and some mammatus we wouldn't have seen back east, we turned toward the Interstate for a long drive back. That plan was interrupted by a violent display of lightning to our north and west as darkness fell. I had been wanting to try lightning photography for some time, and the new storm was a convenient opportunity. As we came to I-35 not far from Tonkawa, radar indicated the storm had split, and while the northern split again looked more attractive, the closer storm displayed a distinct notch on its southeast side that we thought bore watching. We took I-35 north to the next exit, Blackwell, and drove west on OK-11 toward the light show.
My first experiment in lightning photography took place on a desolate dirt road a few dozen yards north of OK-11, and went fairly well. The storm was now severe-warned for hail up to baseball size, and we decided to cautiously draw closer on OK-11. Suddenly, just past Deer Creek, raindrops splattered on the windshield, and I promptly pulled a U-turn to save my poor Cobalt from a brutal pelting. We'd almost gone too far west, because once we came back into cell phone range, radar showed the storm had turned from a northerly course to an easterly one and was now barreling right at us. It had also begun to rotate strongly, earning a tornado warning from the NWS in Norman. Thankfully, it was a slow mover, and we stopped for a few more shots (including a nice CG) before flying south on I-35 back to Tonkawa.
From there, we headed west about a quarter mile on U.S. 60 before pulling over. This is where things got interesting. As I set up for more lightning exposures, chasers appeared by the truckload, hurtling down the two-lane road at breakneck speed into the maelstrom as we watched intently from the soft dirt shoulder. One group stopped just down the road.
An unmistakable wall cloud emerged from behind a stand of trees to our west-northwest. The stacked-plate structure was awesome, even by lightning. (Yes, these photos are of the same storm! The difference is the distance, as well as the angle of the lightning.)
Rotation was impossible to discern by lightning flashes, but little fingers were hanging down in different places every time we got a glimpse. Inflow cranked up from a stiff southeasterly breeze to a jet that threatened to blow my tripod over and rolled my shirt up my back. Despite all our verbal encouragement, the storm failed to put down a definite tornado while we watched, and inflow became chilly outflow. I snagged one more shot of the wall cloud, now practically scraping the ground, due north of us, and we headed off down I-35 for some much-needed food and rest. This shot shows a seemingly lighter area illuminated by lightning just above the wall cloud; I can't help wondering if this tube shape is actually the storm's updraft, clear of precip.
The storm continued to produce significant hail past midnight as its right turn carried it all the way across northern Oklahoma. Unfortunately, while it wouldn't tornado for us out in the middle of the fields, it decided to try a little harder shortly thereafter as it moved past Tonkawa into the more populated area around Ponca City. A 94 mph wind gust was reported there, and possible tornadoes did damage in the vicinity.
It was an enjoyable chase once we got a good storm, but we learned something important: chasing with iPhone radar apps is dangerous (particularly at night) and demands awareness. We got out of range and while we were flying blind, the storm took a 90-degree turn right at us and we were lucky to be in a place where a U-turn was safe. Our basic severe storm knowledge slipped our minds in the heat of the moment--we should have expected a strengthening storm in that environment to move right, though maybe not as sharply as it did.
All in all, it was a good day and an awesome night. I'm now hooked.
