May 26, 2015

Statistics

Initial Target

Start

End

Storm Intercepts

Tornadoes

Hail

Wind

Features

Miles

Wichita Falls, TX

Ardmore, OK 10:34 AM 5/26/2015

Wichita Falls, TX 9:01 PM 5/26/2015

Metcalf Gap, TX

1.5"

76 mph

Tornado, Funnel, Wall Cloud

382

Summary

Dryline play in north central Texas. Awaited initiation in Wichita Falls before intercepting tornado warned storm west of Graham, TX. Noted severe hail, wall cloud and occluded base before storm went HP and started cycling on the southeast RFD flank. Emerged from precip core under RFD gust front noting developing weak tornado. Encountered weak tornadic winds with large bowl funnel overhead. Repositioned southeast for new cycles, but HP mode obscured visibility and called chase as structure eventually degraded.

Crew and Equipment

Chase partners: Jennifer Brindley Ubl, Mike Brown, Sean Casey, Justin Walker, Herb Stein. Equipment: Canon 60D, Canon t2i, Canon EFS 10-22, Canon EF 50mm, Sony HDR-xr500v.

Video

Map

Details

This is the first chase log I’ve written since Herb Stein passed. We lost him in February, 2016 to cancer. I thought I’d share some words I wrote then:

We lost a legend today. Herb Stein had one of the most incredible careers of any storm chaser ever. I only got to know him just this last season, but he left a huge impact on me: his character, his knowledge, and how he loved to share his amazing journey with us. I'll always remember him getting on the radio as TIV and Doghouse caravanned across the Plains. He'd point out spots where he had seen tornadoes, and could tell us all about the history of the locations we were passing, a real fountain of knowledge. I was barely starting school when he was documenting violent tornadoes on groundbreaking science missions. He was really fond of his April 26, 1991 Red Rock, OK intercept, a legendary event and Herb got some amazing photos. He told us stories of driving Doppler on Wheels and being completely overwhelmed during the carnage of May 3, 1999. The winds recorded by that DOW are still the fastest ever record on Earth. Brindley and I got to watch his raw footage and narrated account from May 27, 2013 when Herb experienced EF4 intensity winds within the core of a wedge tornado while driving the Tornado Intercept Vehicle. But life was more than tornadoes for Herb too, and that's something that impacts me the most, something I reflect on when I get too caught up in all of it.. He knew how to have fun, loved the outdoors, enjoyed all of life, and a missed storm didn't get to him. He was a goofball too. One of my fondest memories is of him throwing peanut M&M's out of TIV's turret at our windshield (pictured here). We're sad he's gone, but he had an incredible run, will always be remembered, and lived several lifetimes of adventure.

Tuesday, May 26, was another modest shot at a tornado in north central Texas. It was our fifth day out with Sean Casey and the TIV/Doghouse crew. A dryline was forecast to push into and focus over western OK south through Wichita Falls, TX and into central Texas with strong instability to the east. Shear was relatively lacking across the dryline with some modest northwest flow aloft and light southerly flow at the surface, which kept the tornado probabilities fairly modest. A morning MCS tracked over Oklahoma during the morning and left worked over, stable air in its wake, which wound up killing the north half of the target. We set our initial target for Wichita Falls, TX for mid afternoon supercell initiation as the cap looked like it would be open early. We’d just be waiting for peak heating and some flow aloft to kick things off.

After lunch at our usual joints in Wichita Falls, we relocated to a department store to pick up odds and ends for the trip and then await initiation. Most importantly, I needed some shorts. Temps were climbing into the upper 80’s with dews hitting 70 and so pants were no longer cutting it. We needed the moisture rich air and strong heating to destabilize the atmosphere so we could get robust storms, especially with the modest shear we were working with.

By midafternoon we had storm initiation about 80 miles to our south southwest with cells heading toward Graham, TX. It was a bit further than we expected and it was a scramble to get down there in time. The storm went tornado warned as we approached from the north with no view through the forward flanking precipitation core. We core punched the back end of the storm. I reached out of Doghouse’s passenger window and pulled our windshield hail guard down just in time. A large stone, probably an inch and a half in size, pinged off the steel grate moments later.

We emerged from the core of the storm and came out under a small block wall cloud. Terrain was a little iffy with lots of trees and small hills broken up by intermittent crisscrossing roads. We started stair stepping east and south to get downstream of the storm. Finally with an open view to the northwest we had a great view of the base of the storm. The RFD clear slot and gust front had occluded, the updraft base bowed out. We’d be waiting for the next cycle of the storm for a shot at a tornado. Meanwhile a tornado report had come in on the storm not long after this shot was taken, but we didn’t have a visual on anything obvious.

The sky went green as the storm turned into a beastly high precipitation supercell. The storm was cycling and we cut north to get into the inflow notch, putting us directly in line to get swallowed by the mammoth core, so I dropped the hail guards again anticipating large hail. The radar velocities showed an intense couplet deep within the core, but the sickly green rear flanking downdraft totally obscured it from view. We waited several minutes under pea green skies for the storm to approach, hopefully gaining some visibility in the process. The power lines buzzed next to us. BOOM! Lightning struck with nearly instantaneous thunder. We were staying in Doghouse now. The radar updated. The tornado was moving southeast. The motion was unusual, and we’d have a difficult time positioning for an intercept.

The huge bowing RFD core, spanning several miles, started to cross the road to our south. The storm began to cycle, but catching us off guard, it was cycling on the southeast flank of the RFD gust front. Supercells most often cycle to the northeast, developing a new updraft base, wall cloud, and tornado cyclone on northeast corner of the occluded horseshoe shaped updraft base. However, we quickly realized that the northwest shear vectors that were driving the storm’s evolution were causing propagation and cycling downstream to the southeast. We’d have to core punch the rear flanking downdraft now to get into position. We headed south, plowing into the core and passing behind the circulation as it had already crossed the road ahead of us and dissipated. Hail got up to one inch in size, but nothing huge hit us.

We turned east toward Metcalf Gap to get out from under the core of the storm. Finally, the driving rain and hail let up and we could make out the silhouette of some storm structure up ahead. A ragged gust front emerged, adorned with pointy whale’s teeth like scud:

I stuck my head out to get my bearings and a feel for what the storm was doing. Our approach through the RFD core to intercept a southeast cycling supercell was bizarre and unorthodox. One of the TIV’s primary missions for the IMAX film we were shooting was to deploy probes in the path of tornadoes. This necessitated a chase style with added risks I normally wouldn’t take on my own, and in this case included positioning directly under the rear flank of a storm without a visual reference to the tornado producing end of the storm. I was disoriented without that reference point. I got out of the vehicle to feel the winds. We had a moderate, lukewarm west wind: outflow from the RFD. The structure immediately in front of us looked like it was being driven by outflow as well. A 360 look around us didn’t yield any sight of structure that looked like it was being driven by an inflow based feature that could become tornadic, such as a pronounced inflow tail or wall cloud. This lulled me into a false sense of security that we were safe at our position. What I hadn’t realized was that the tornadic structure I was searching for was immediately over us and all around us. Despite there being outflow at our position, the ragged gust front ahead of us was being dramatically driven by inflow, the pointy scud fingers rapidly drawing in more cloud material as the storm ingested unstable outflow. We were sitting immediately under the center of the wall cloud, blind to that fact at such close range.

Vortex Spotted
13 miles NNE of Strawn, TX
5:55 PM

There was a lake to our north, and spray started to kick up on its surface. “Ok, it’s the outflow winds from the gust front hitting the lake, no big deal,” I thought to myself. A small, but tight circulation developed on the lake, kicking up a twisting white spray of water. “TORNADO! TORNADO! TORNADO!” Brindley called out, sitting on the window frame of Doghouse while shooting the feature. The winds, the structure, and everything around us said outflow to me, so I quickly dismissed the feature as just a gustnado, a smaller, weaker eddy on the storm’s gust front that is not tornadic. It was moving the wrong direction, however. Gustnadoes usually move away from the storm, carried by the outflow winds. This vortex looked like it was heading southwest, toward the interior of the storm. It was being carried by the inflow notch winds right at the top of the wall cloud. The motion was a big red flag but I was still oblivious, stubbornly determined that we were chasing an outflow driven gust front. The vortex became invisible as it moved onto land, no longer having any water drop tracers and the lush greenery didn’t provide the usual dirt debris cloud either. It was heading our way, but we had no visual on its exact direction now.

The anemometers on TIV’s stick probes, visible through our windshield, faced east with the outflow but then slowly turned all the way around to face us. The change in direction marked the approach of the circulation.

The winds were suddenly upon us, a constant jet. The velocities then steadily but rapidly intensified. The anemometer blades on TIV’s stick probes spun away. The wind vane tails were getting buffeted hard back and forth and now turned to face north. Doghouse started to rock, and the power lines next to us swayed violently back and forth. The driver’s side window was slapped by a piece of plant debris as the winds roared well above severe limits. “Helmets on, seat belts on!” Mike Brown and I said, bracing to ride out the winds.

Mike Brown was loving it, shouting lines from Mad Max: Fury Road and very much looking like a character out of the movie. "What a lovely, lovely day!" Brindley, however, was terrified and flustered. Being impacted by a tornado is a worst nightmare type of situation.

But I wasn’t even sure what was impacting us, and wanted to be calmly reassuring while focused on what was going on. I still didn’t have situational awareness. The winds did not feel like outflow at all, but more like a driving inflow jet with directional shifts, and I didn’t understand from where they were coming. Scanning the horizon in every direction, I didn’t see any storm structure that warranted these winds.

Then it dawned on me. I rolled down the window as the winds started to slack off a bit, stuck my head out and slowly tilted to look straight up. Hanging directly overhead was a huge bowl funnel. I felt incredibly tiny and timid at that moment as the spiraling round mass absolutely dwarfed us and as I realized where the power behind those winds originated. I got the camcorder on it a few moments later as the center of the circulation moved off of us, but it still completely filled my frame.

Funnel Overhead
13 miles NNE of Strawn, TX
5:59 PM

The tornado was already moving away from us as I made sense of the situation and with great tension. Brindley captured this extreme wide angle of the funnel at close range, suspended beneath the spiraling wall cloud, the rush of wind from the ground circulation still audible in the brush to our south. It would have been an exquisite shot for the IMAX movie had it proceeded to fully condense, but the tornado instead dissipated.

Ending The Chase
4 miles WNW of Jacksboro, TX
8:11 PM

I called over the radio that we had just been impacted by a weak tornado. Justin Walker later pulled the readings off the anemometers. Velocities peaked at 76 mph, weak indeed for a tornado in the EF-0 category. It was a stark reminder that, despite as intense as the moment was, tornadoes get so much more intense. Chasing without armor in the Doghouse, it was also a stark reminder that we must make every effort to avoid impacts from such tornadoes.

The storm was cycling and the chase continued without much time to dwell on what had just happened. The velocities spiked again on the radar, but once again the circulation was buried in the precipitation core. We did not aggressively pursue the tornado, as the vortex would probably be worthless from a filming perspective anyway.

The storm cycled again on the southeast RFD gust front. We were ready this time, however, and had the knack down to chasing this pattern. Again we punched the storm from the north and emerged under a ragged gust front. Herb Stein called out over the radio, “This looks familiar.” We held a little short this time and watched the structure above us. A tight spiral in the base twisted away not quite overhead, and we prepared to shoot the next developing tornado. Unlike last time a funnel did not descend, however. It was the last cycle of the storm before the cell started to fall apart. We called the chase and started heading back up to Wichita Falls for a room.

TIV could handle a tornado encounter like that no problem, but the Doghouse doesn’t have steel plated armor or polycarbonate windows. We were definitely not supposed to be in any tornadoes and were to hang back during such encounters. I was filled with a mix of emotions as we drove away from the storm. I felt exhilarated, an incredible rush from the encounter. And I was also racked with guilt. I felt guilt for feeling exhilarated by such a dangerous and reckless encounter, guilt for failing to recognize the situation I put us in, and guilt for putting Brindley through that kind of danger. She was upset at me and sick to her stomach from the encounter and that also broke my heart. I vowed to myself to never let that happen again.

"Mad Mike" Brown driving us home for the night:

Driving Into The Sunset
21 miles NW of Jacksboro, TX
8:25 PM

Conclusion

Well, we had an intense and dramatic tornado encounter with the TIV crew finally. Unfortunately, it was the direct result of my irresponsible failure to keep the Doghouse, which is not an intercept vehicle, out of tornadoes. Our encounter put everyone in the vehicle in danger and almost ruined my chasing partnership with Brindley. I take full blame for that. Our chasing strategy and motives led me to engage in maneuvers I normally wouldn’t. The weak tornado initially displayed rather disorganized structure, which made getting my bearings difficult too. These aren’t meant to be excuses, but explanations for how somebody who is a strong advocate of safe storm chasing practices, winds up getting hit by a weak tornado. I consider this another lesson learned the hard way, and write these logs so that I and maybe others don’t repeat the same mistakes. Another unfortunate aspect of our encounter is that the tornado was probably not ideal for our film shoot. The large bowl funnel was too close and then didn’t condense once it moved off of us, and did not have a photogenic debris cloud either. The supercell wound up producing several weak to moderate tornadoes, but due to the HP storm mode, roads, and terrain, we were only able to document one of them. The storm was also unusual for its southeast propagation and cycling. I hadn’t chased a storm quite like it before, but am now on the lookout for that pattern when we have northwest shear vectors.

Lessons Learned

Abort and take your escape route if you lose your visual references and situational awareness.
Don't get locked into assuming structure is outflow driven and thus without a tornado risk.
Northwest shear vectors can cause propagation and cycling on the southeast flank of the RFD gust front.

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