March 2, 2012

Statistics:

Initial Target: Greensburg, IN
Departure: Westchester, IL 8:30 am
Arrival: Clarksville, IN 4:30 pm/Westchester, IL 3:00 pm March 3
Intercepts: Henryville, IN (via Memphis, IN 4PM EST)
Tornadoes: 1
Hail: Severe (2" estimated)
Wind: Non-Severe (not measured)
Features: Tornado, Wall Cloud, RFD Core
Miles: 639

Summary:

High risk, moderate instability, extreme shear cold front setup across Ohio River valley. Targeted Greensburg, IN initially for fast moving tornadic supercells. Retargeted south toward Louisville, KY to area of better instability ahead of mature, tornadic supercells. Intercepted lead cell in training line in Memphis, IN noting large multi-vortex tornado with violent motion. Attempted to pursue storm northeast, but damage path and road network prevented following. Returned to original vantage point to watch second cell in training line approach. Noted HP RFD core with dramatic wall cloud, but no tornado. Dropped south to avoid core, but couldn't escape in time and cracked windshield on 2" hail. Returned north to briefly to duck out of solid line approaching from west while continuous streams of emergency vehicles funneled into Henryville. Called it a chase at 5:30 EST and met up with other chasers for dinner.

Crew and Equipment:

Chase partners: Jennifer Brindley.  Equipment:  Kenwood TH-F6A Tribander, Dell Inspiron Laptop.  Millenicom 760 USB datacard and cradlepoint router, Holux 236 GPS, Canon 60D and EF-S 10-22mm

Photography courtesy: Jennifer Brindley

Video:

 

Details:

The first chase setup of 2012 fell on Friday, March 2. I was planning on passing on the early setups that were oversheared, too lacking in instability, or in terrible terrain. The models started plotting a significant event over the Ohio River valley, and consistently plotting the triple point and ingredients for tornadic supercells over the favorable terrain of central Illinois and Indiana. The event had my attention and I started to making serious plans to chase, while cautiously watching the models to see if the setup would hold together.

An extremely impressive 110 knot midlevel jet with a bombing surface low was forecast to eject out across the Ohio River valley on Friday. Dewpoints above 60 were being plotted as far north as Champaign Urbana on some model runs. Forecast instability was relatively modest at 750-1500 in the warm sector near the triple point. Coupled with forcing from the upper level dynamics, however, we had more than enough lift to maintain robust updrafts. Shear profiles were incredible with huge curving hodographs, 70-80 knots of bulk shear and 1km SRH over 200 through much of the warm sector. Initiation looked to occur along a fast moving cold front by early afternoon under a weakly capped atmosphere. Given the hodographs and shear profiles I figured the initial mode would be discrete supercells, possibly low topped/mini-supercells with the modest instability, but the forcing on the cold front would eventually cause a transition to a rather solid line with embedded supercells. The surface low was forecast to deepen below 990 mb and track north through Illinois and north of Indianapolis before ejecting. The initial plan was to stick close the surface low where lift would be enhanced, surface winds better backed, and the terrain more favorable for chasing. There were some concerns about cloud cover and lingering precipitation along the warm front, which might kill the instability, however. My target a day before the event was a line from Terra Haute, IN to Indianapolis. Given the 110 knot midlevel jet, I expected storm speeds to be extreme. Way too fast to keep up with any of the cells, the plan was to get well downstream and let them come to us, hopefully catching something of interest as they sailed past at warp speed.

I made plans to chase with Jennifer Brindley Ubl, now my regular chase partner. She was down in Chicago for a concert already so instead of going home she crashed our place for the night. I spent a few hours overnight working frantically to get the van ready to chase. I wasn't prepared at all yet to chase, with all of my projects in a half done state. I had purchased a 22" touchscreen monitor to use with my laptop. I got it mounted in a half assed manner for the chase, while the center console was detached with exposed wires.

The gremlins were out in full force. The extra DC outlets I had just wired were not working, a loose wire probably. The DC outlet in the rear of the van was loose and only worked with a lot of pressure. My Millenicom datacard had been activated that morning and the cradlepoint router wasn't connecting to it. Luckily I have backups of everything. I tethered my Sprint smartphone for data so I didn't need the extra data outlets, cradlepoint router or datacard.

The 0z models runs the night before the chase looked less favorable. The surface low was further south than I wanted. To play the triple point I'd be in the trees and hills of southwest Indiana. Instability was greater further south in Kentucky and Tennessee, but the terrain is almost impossible to work with down there, and the surface winds were badly veered south of the low. I figured my best bet now was to wait for the cells to reach southeast Indiana where there is some decent farmland to work with. My new target shifted to Greensburg, IN.

Brindley and I were rolling the next morning by 8:30 am. The Storm Prediction Center had upgraded to a high risk, with 30 percent tornado probabilities. A quick peak at the RUC and visible satellite showed conditions very favorable for tornadic supercells, but over even less favorable terrain than I had hoped for. The clearing on the visible satellite, needed to destabilize the lower layers of the atmosphere, was hugging the Ohio River valley. We'd have to get close to the river to realize decent instability and the terrain and roads are just terrible down there. The warm front was socked in with clouds and rain, keeping the boundary layer too cool for surface based storms. The triple point was no longer in play. The RUC showed 2000 J/Kg SBCAPE over Louisville, KY with the best shear/instability combinations at 21z and cells moving through the location at that hour. This became our next target. I wasn't thrilled to be attempting a chase down there but decided to go for it, making a play along I-65 and hopping down the line of cells as they passed.

We made great time to Indianapolis. We passed in the wake of some elevated severe thunderstorms that dropped baseballs on the southeast side of town. We passed a car with it's back window missing. If they wanted an auto loan they might actually consider going to https://www.roadloans.com to find information on getting bad credit auto loans to replace their windowless car with a new one. Auto credit loans can come in handy when you live in a tornado-prone area where cars can take some pretty hefty damage. Luckily we were able to stay clear of the storms. "Particularly dangerous situation" tornado watches went up over Illinois and Indiana by late morning in typical high risk fashion. A line of cells had gone up across central IL. A tornado was reported on one of them, but the line quickly congealed into a solid mess and looked like it was over cold outflow from the Indianapolis cells. New, discrete cells were firing to the south, well ahead of the cold front and quickly moving into Indiana. They quickly gained tornado warnings with reported funnels. One in particular was tracking along I-64 in southern IN. We hoped to catch it as it crossed I-65. Still two hours out, I figured the environment would maintain the cell until we got there. We took 465 to 65 south out of Indianapolis and hit a snag almost immediately. An accident closed the two left lanes of the interstate. The delay almost cost us the chase.

New cells fired ahead of our target supercell, which further reduced the time we had to make it south in time. I kicked it up a notch and we beat the cells south before they crossed the highway. Our first stormy sky of the season came into view as we passed Scottsburg, with an anvil stretching overhead and low cumulus feeding into a dark precipitation core. It was pretty hazy so I knew we'd have to get fairly close to the storm to have a decent view.
Passing Scottsburg, we started looking for a place to pull off the interstate and get a view of the updraft base of the leading cell in a line of training tornadic supercells. Henryville sat squarely in the tornado warning polygon and I exited there hoping to find a place with a view. Clark State Forest sat immediately to our west. Huge tree filled hills blocked any view we had of the western horizon. I turned east into town, hoping to find open fields on the other side of Henryville. The sirens wailed ominously. At the main intersection in town there was traffic lined up in all directions at a four way stop. One direction had a line of a dozen school buses, each one loaded with kids. I was mortified at the spectacle of a supercell with a history of producing tornadoes bearing down on the buses. I realized that we'd have to commit to intercepting east of town if we made it through the intersection. There was no guarantee we'd find a reasonable place to spot the storm from once through the town, and there would be no getting through that intersection again before the storm hit. The situation was all kinds of wrong. I pulled a U-turn and started heading back toward the interstate. We didn't know it at the time, but Henryville was just minutes from complete devastation, and it was spooky to have to stopped there and seen the traffic in town going about their business and school letting out with the sirens wailing while a violent tornado was bearing down.
We headed south on 65 and got off at the next exit, Memphis. With great luck, there was a truck stop perched on top of a hill with a clear view to the west. The leading supercell in the line quickly approaching with bolts arcing across the sky and crackling thunder.
Another car was parked facing the storm and I walked up to say hi and was greeted by chasers Simon Brewer and Jim Bishop.
The updraft came into a view. A dark lowering extended from the center of it. Was it a wall cloud? Tornado? We couldn't immediately tell.
I setup up my camcorder on a tripod and zoomed in on the feature. The motion was rapid and it contacted the ground. A large tornado was on the ground and it was rapidly approaching. Sirens were blaring at this location too, yet the traffic at the gas station seemed almost complacent. Lots of cars were at the pumps filling up and trucks were idling in the back lot.

A black and white still showing the storm structure and large tornado:

A truck driver strolled up to us to see what was up. He seemed oblivious to the tornado. I stressed he needed to get on the highway and head south immediately to get out of the path. He stayed awhile and then reluctantly strolled off.

Brilliant power flashes illuminated the base of the funnel as it rolled over some transformers:
The funnel approached with dramatic motion. The white hue and twisting swirls reminded me of a giant soft serve ice cream cone.
As the tornado got closer we could see multiple vortex structure. Suctions vortices were spinning wildly under the funnel before jutting off horizontally and wrapping around the main funnel.
Sub vortices being sheared off the main circulation:
We carefully watched the tornado to gauge its movement and make sure we were clear of it. Using the telephone poles for reference we could see the funnel had a clear left to right movement, meaning it would pass to our north.
A wild sub vortex of the tornado twists horizontal with a whip like tail. The funnel looked like a fist with a finger prodding the ground as it dragged along the hilly southern Indiana countryside.
Jenn shoots the approaching tornado:
The tornado hit a structure with black specks of debris visible in the video. The multiple vortices, structure, and debris all pointed toward a violent tornado capable of inflicting massive devastation.
The tornado's condensation funnel darkening in color with changing light and taking on a more turbulent appearance:
It started to rain pretty good at our location, our cameras getting wet while the tornado moved over the background hills into the valleys in front of us:
Horizontal vortices spiraled around the violent funnel and writhed like tentacles. Only the most powerful tornadoes exhibit this plethora of sub vortex structure. It was an incredible, astonishing sight.
Noodles of vorticity as Kinney Adams had dubbed them, created by the interaction between extremely intense updrafts and downdrafts:
The funnel retreated as the rain filled in, but a strong debris cloud remained at the ground. The tornado was very much still in progress.
Another horizontal sub vortex funnels perpendicularly into the main tornado just off the ground:
A wide angle shot capturing the tornado and parent storm structure:
Simon and Jim left to find better viewing out of the rain. The funnel took on a classic cone shape with tight debris cloud.
Jenn snags my picture as I shoot video of the tornado, funnel aloft with debris cloud underneath.
The rain was coming down hard and the funnel retreated. We too decided to move to find better viewing as the tornado was passing to our north. We headed just west of the truck stop where a field opened up to the north across from a housing subdivision. Dramatic supercell structure came into view with an updraft base cut by a deep rear flanking downdraft, the tornado fully condensed again into a large stovepipe. This was shot moments before the tornado entered Henryville.
We made a futile attempt to go after the tornado. We headed back to 65 and went north. The storm was racing off to the northeast and we were caught well behind the rear flanking core with no view of the tornado. As we headed up the interstate, I realized we would never be able to catch back up with it given there were no decent eastbound highways, and that 65 was probably a mess up ahead. The tornado had crossed the interstate. It was either going to be closed by police, strewn with debris, or jammed with traffic. I pulled a U-turn at the next turn around and we headed back south.
Another tornadic supercell, just as impressive looking on radar as the first, was right on the heels of our first storm. We returned to the same truck stop to watch it approach with a dramatic alligator mouth wall cloud, purple updraft base, and green rear flanking core. There was no tornado that we could discern, but we were sure it could have produced one at any moment.
This storm was more south than the first, and as it approached we realized we were sitting square in its path. Meanwhile, a boy of maybe 13 had walked up to us to see what we were doing. We told him we were storm chasers, and that he had has family needed to get south right away to get out of the way of this approaching storm. He didn't leave, but his family soon arrived. I explained the same thing to them, and after some nudging, they eventually got spooked and started to scurry away. The boy stayed, however. The family screamed to him as they shuffled down the truck stop ramp and he eventually ran after them.

My ham radio crackled with a familiar voice. Fellow Illinois chaser Jesse Risley had found us. He pulled in and got out, the first words out of his mouth, "I didn't think I was going to make it." Jesse raced the Henryville tornado across I-65 and just beat it.

Our storm grew closer and closer and we lingered a bit too long before we finally decided to duck south on I-65. The streaky bands of precipitation started to overtake us on the highway and I feared we might get caught in a developing circulation. Two cars up ahead were driving side by side at 55 mph. I laid on the horn until one of them finally moved, and we floored it to clear the storm rapidly crossing the highway, Jesse just behind us.

Dark bands of rain, rapidly moving east to west were crossing the road ahead of us. It was an unsettling site. An object from the sky then rapidly approached us. Jenn and I both saw it coming but we had no time to react to it. A white baseball, on the same trajectory an outfielder would see, was coming in fast. SMACK! It hit the windshield dead center and left spiraling cracks. The stone was probably in excess of two inches in diameter. Moments later a second one struck the roof with a booming thud, leaving a big dent.
We raced ahead and were out of the storm seconds after the hail assault, cruising under calm, clear skies. We encountered just two hail stones. One cracked the windshield, and the other put a nice trophy dent in the roof. A storm chaser badge of honor.

We took the next exit and stopped at a gas station for Jesse to fill up and for all of us to catch our breath. The family at the truck stop was waiting there. They had made it out of the storm's path, but more tornado cells were approaching from the west. The line of cells had congealed into a solid mess. We'd have no view on them, so we decided to call it a chase and get out of the way. Our best course of action was to head north a short ways and let the northern end of the cell overtake us where hopefully the severe weather would be minimized. Jesse followed us up a county highway.

One of Jenn's local's portraits:

We stopped just shy of a minisupercell that was passing behind the larger supercell we had just fled, and let the top of the next approaching supercell hit us. It packed an oompf with strong to severe winds and a smattering of small hail at the end, but afterwards we were clear of all the weather. We decided to head south toward the closest decent sized town, Louisville, KY, and get some dinner. A continuous stream of emergency vehicles was coming up from the south. Ambulances, fire trucks, and police, all funneling into Henryville with their sirens blasting. We didn't know how bad the damage was at that point but we figured it must have been significant. The sun soon came out and the skies cleared behind the front and it was a beautiful day. We got a victory dinner at the Outback Steakhouse in Clarksville, IN. The celebratory mood was quickly cut short, however, as the first images of horrific damage came in on the restaurant's TVs. Another Illinois chaser, Mike Brady joined us for dinner later on and told us he too had a close encounter with the tornado as a small tree practically fell on his car.

Jenn and I decided to spend the night in Clarksville as we didn't want to make the long drive home after the busy day. I-65 was closed at Henryville due to the damage, and it was snowing up in Wisconsin, so we decided it was best to just stay put. We were rolling the next day under sunny skies. Significant damage was evident from the highway as we passed the Henryville exit. It was a heartbreaking sight.
Conclusion:

March 2 second turned out to be one of the largest March tornado outbreaks ever recorded. The Henryville tornado that we documented southwest of town was rated EF4 and responsible for over a dozen fatalities. Over thirty were killed during the outbreak. It was a horrifically tragic event. While our chase had been exciting and the sight of the tornado truly awe in spiring, a chaser never wants to see those caught in the path suffer. It was heartbreaking watching the news later and seeing the images of destruction and hearing about the deaths. We did our best to submit reports of the tornadoes to the National Weather Service as we saw them and warn people that we encountered, but we felt helpless for the folks in Henryville. Jenn and I got some of our best tornado shots ever, but we're both looking forward to chasing more relaxed setups in better terrain, over the more rural parts of the Great Plains where less people will be affected by these violent storms.

 

Lessons Learned: 

  • With a fast moving storm in bad terrain, find a spot with a view well downstream and wait for the storm to come to you.
  • Take your escape route sooner than you think to avoid nasty encounters with damaging hail.
  • Deadly and devastating tornadoes take the fun and excitement out of storm chasing.