May 20, 2019

From my daily chasecast email:

“Day 1 Today: Extremely volatile warm sector. Lack of capping, upper level forcing in place, and explosive instability, favorable wind profiles suggest multiple waves of tornadic supercells across the warm sector. East of Amarillo, to east of Oklahoma City, south to Abilene and east to Wichita falls... you could position anywhere in there and probably be within easy strike range of a tornadic supercell today. The environment on the HRRR is such that any discrete, robust updraft will probably pose a tornado threat.

Primary initial staging points to me would be on I-40 in the eastern TX PH and western OK, which is where we are. And I-44 from OKC to the Red River. That should give you a nice fast highway to position for upcoming storms.

Expect storms to fire out across the open warm sector, a weak surface trough is hinted at on the HRRR which would fire storms along I-44 and send them up toward the OKC area.

The dryline along I-27 looks to initiate and send storms moving quickly northeast toward I-40. Play your cards right and don't get bogged down, stranded, or taken out of commission, and you may actually get to play multiple supercells.

We are holding in Elk City, OK for now and will monitor visible satellite, surface obs, and radar, but I see no reason to move at the moment. HRRR suggests we'll be intercepting just west and then just south of here.

Interesting that the 0-3km CAPE doesn't really show up until mid afternoon. So the tornado show might not start super early, but just overall CAPE and dynamics may counter that regardless, so expect warnings right away.

Environment looks most primed in the 5-7pm time frame, if you can get something discrete and still classic by then. Even if storms are HP or embedded in an MCS, the shear and tornado parameters are such that there will still likely be embedded and rain wrapped circulations. Just avoid chasing these.

Watch the positioning of the warm front. It looks like it's convectively reinforced and is razor sharp. You'll want to stay south of it because it will force your storm elevated. HRRR keeps it north of 40, but some earlier models were hinting that it could crash south. If that's the case, you might be making a mad dive for Wichita Falls.

Strategy tips for today: I might suggest setting up miles downstream and letting these fast moving storms come to you. Motion looks like storms are coming out of the west southwest and speeds of 40+ mph. It's going to be very difficult to keep up. Have a couple escape routes ready to go as the storm approaches. You do not want to race across the tornado's path or the RFD core to escape! Head north if you wind up in the notch and have to escape. You're going to get toasted by softballs, but it's way better than driving into a wedge.

Avoid the chaos? Pick up Tail End Charlie down by Abilene, or a more discrete supercell in the southern TX PH near Childress.”

Monday, May 20, 2019 was forecast to be a major tornado outbreak. The Storm Prediction Center issued a rare 45% probabilistic tornado outlook, which was only the second time I had chased probabilities that high (the other being April 14, 2012). An explosive environment was forecast over Oklahoma with strong wind shear and an open cap. Multiple waves of tornadic supercells were expected, with some potentially violent tornadoes. Brindley and I weren’t particularly excited about the day. High Risk setups often come with a high risk of busting and dangerous conditions due to storm mode and traffic. If anything, we were a little apprehensive about the day and loathing what chasing an Oklahoma High Risk was going to be like. Still, we thought the day would have plenty of potential for a great intercept, and more than enough storms to spread out chasers. We hoped to catch one away from populated areas, and perhaps on a secondary target away from the crowds. We loitered at our hotel parking lot into the early afternoon. We were already sitting close to the warm front and I-40 let us move quickly east or west to catch storms coming up toward us. I thought our position was pretty much primed. Skies were grey, overcast, and dreary. The air was thick with moisture carried on a strong south wind. It was the kind of oppressive gloom that is the hallmark of the start of a High Risk setup. I took a picture of the foam cheeseburger that sits on the dash of the Subaru. A keepsake from the 2014 National Storm Chasing Convention, they were handed out to everyone in honor of Tim Samaras, who kept the same, real McDonald’s cheeseburger on the dash of his car for years as a good luck charm. In addition to remembering the Twistex crew, I look at the cheeseburger as a safety reminder. This day had the potential to get a lot of storm chasers in trouble with fast moving, high precipitation storms harboring potentially violent tornadoes.

“I gotta go, Julia. We got cows.”

The dryline started to erupt in the Texas Panhandle and we decided to move on a storm heading northeast toward Wellington, TX. A middle of the line cell, we hoped to avoid a crush of chaser traffic. We drove south and turned west at Hollis. Traffic seemed to go about its usual business while a Particularly Dangerous Tornado Watch was in effect instilling a sense in me of impending doom.

Ten miles southwest of Wellington, TX, the base came into view, backlit against an orangey sky. A nub funnel was already wrapping up. “Here we go,” I thought, the start of a long day of tornadoes.

We scrambled to get cameras ready and report the funnel to the Weather Service. Our road was devoid of chasers, with most everyone on the Tail End Charlie storm or still hanging around downstream on the warm front or Oklahoma warm sector. Streaky bands of rain circled around the low level rotation like a curtain. Tornadogenesis looked imminent. But then it just didn’t happen. The funnel drifted apart lazily into fragments of scud. On a day with maxed out parameters, the storm just couldn’t pull it off. Maybe it wasn’t ready yet, and needed to cycle a few more times.

We turned north toward Wellington and drove under the huge RFD clear slot. Brilliant white hail shafts extended off the back of the storm. We passed a few stones lying on the sides of the road that were approaching baseball size.

The storm wrapped up over Wellington like it was gearing up to produce, which was bad timing for the town. The lowering looked menacing, but also a bit disorganized. And once again, the storm didn’t produce. Perhaps it was running over too much of its own hail cooled track this time. Meanwhile, Tail End Charlie to the south near Childress was producing tornadoes.

We ran east and north back into Oklahoma to get downstream for the next cycle. Then out of the northwest came the harbinger of our storm chase’s death: a ground scraping shelf cloud. The cold front was surging and the winds behind it felt icy compared to the muggy High Risk warm sector airmass. The surge of cold air obliterated our storm, and we were suddenly searching for a new target.

The surging cold front killed off anything chaseable to the north, and the socked in warm sector had stunted additional storm development. Now there was just one dominant supercell tracking into southwest Oklahoma. We knew every chaser in the world was going to be on it and that a huge traffic jam was going to ensure, but it was either go for it and see if we could get a view, or just call the chase. We headed south through Hollis, OK on a direct core punch through the forward flank. On a day that also featured 45% hatched hail probabilities, we were surprised to find no hail at all on our route through the core. Warm sector lapse rates away from the Caprock dryline must have been lacking along with saturated profiles making for watery, mushy updrafts. We stopped a couple miles south of highway 62 between Hollis and Gould on the road grid where we bumped into Brandon Sullivan and others. We chatted for a couple moments directly under the updraft base. Even at that close range, visibility was bad due to haze.

We turned back onto 62 and that’s when we found ourselves in the “conga line”, an endless line of slow moving storm chaser traffic. The storm began to cycle downstream to northeast, which put us behind, and now we had no way to catch up and get in front of it. We had loitered too long under the base chatting it up instead of maintaining a position two steps ahead like we should have on a crowded high risk setup. At every pull off with a view, both sides of the road were lined with chasers looking to north as the storm began to wrap up.

Somebody up ahead hit the brakes and the chaser traffic splayed out across the road.

We turned north on highway 34 toward Mangum, lumbering along in a long line of traffic. Brindley spotted it to the distant north, a white stick of a tornado. The contrast was so bad I could hardly even see it, and had to severely enhance my video shots to make it visible.

It was the rope-out phase of a tornado show that we had missed. A few chasers tried to pass, but still had a couple hundred other chasers in front of them. Traffic puttered along at about 35-40 mph as the tornado faded away to the north.

Most of the chasers turned right and went east out of Mangum on highway 60, so we instead attempted to go north through town and come up the back side of the storm. We hit the damage path on the north end of town, however, and the road was blocked. We turned around before we got too close, not wanting to get in the way of first responder efforts. We made the east turn onto 60 and now were at the end of the “conga line”.

It didn’t matter. The tornado show was long since over, and then the looming cold front came crashing in to kill the storm for good. As soon as we saw the dark shelf cloud approaching we called the chase and cut north through the front. There didn’t appear to be much of a chaseable target left, and the High Risk outbreak was going belly up. We got a room in Clinton on I-40 for the night. I walked into the room and set my stuff down when lightning hit a powerline pole just outside the window. I just happened to catch spotting the bolt as it struck, which was probably a more amazing sight than anything I had seen all day on the chase.