Encounter with a Tornado Part 2
September 18, 2014 Leave a Comment
The June 16th Wakefield Tornado
On June 15th I learned a new weather term: Helicity. If you think of a tornado as having a vortex oriented vertically, helicity is wind rotation that is horizontal. Why is helicity important? As a thunderstorm is forming and warm air is lifting, it pulls the horizontal rotation, bending it toward the vertical, aiding in the storm rotation from which tornadoes are born. On Sunday, June 15th the helicity forecast for Monday was literally off the charts. The attached image shows this forecast as bands of color. The red indicates the maximum amount the models can show which is 860 m squared/s squared. However, the red area is huge and we can only guess how much higher the value actually was.
The whole day of June 16th seemed unreal to me. My chase partners Skip Talbot and Jennifer Brindly Ubl and I woke up to see storms forming in southern South Dakota. We knew this was not the tornado-forming variety, but we had some time on our hands, so we drove north to take a look. The storm was bordered by a dramatic shelf cloud that moved slowly toward us.
Footage of the South Dakota Shelf Cloud
Underneath this structure, the cloud above us was dark, rolling and churning with spooky turbulence. The day’s helicity was very evident. I’ve shot a lot of clouds but never seen such weird movement. For lack of a better term, I call this shot my Harry Potter sky, and I absolutely love the haunting effect.
Harry Potter Sky (clip A195-C037v3)
The violence of the storm overtook us and we took shelter at a gas station mini-mart, but again, this was only the prelude for the day, not the main event. Soon we saw a storm initiating in our target area a hundred miles to the south and rushed to meet it.
In a very rare occurrence, two large F4 (cause catastrophic damage) tornadoes had formed and were bearing down on the small town of Pilger while we were still driving towards it. The sight of these tornadoes was surreal, they were enormous! As we found a place to park, Jennifer, who had been watching the radar, confirmed that we were in the direct path of the closest twister, so we had only a limited time to film. The conditions were less than ideal as we were in the middle of a downpour. I set the Red Epic on a tripod next to the van but everything was getting soaked. Water was splashing on the touchscreen monitor and activating the menus.
I had no control over the camera! Had I come this far just to be thwarted by a technical glitch? After an agonizing minute or so, I did a re-boot. Finally, I got a few moments of precious footage before Skip noticed a new tornado forming above our heads. “We have to leave now!” he said, so I stopped recording, grabbed the tripod with camera still attached, pulled it in the car and we took off to the east.
We found a turnout a mile or so down the road with a clear view and no rain. The twin tornadoes that had hit Pilger had wound down, but the new twister was growing in size and strength. We filmed it as it crossed the road we had driven on moments before. It was a huge multi-vortex wedge-shaped tornado that later was shown to measure F4 in strength, just spinning in the field in front of us. Are we safe? Skip says we are absolutely OK in this spot, and he is describing the event for his video record, giving us a verbal play-by-play of every detail while we watched. I hear Jennifer Brindley Ubl’s camera snapping photos. With my Canon 24-105mm lens, I zoom in on the base of the tornado to catch detail of the multi-vortex. However, I am so overwhelmed I forget to check focus and a full minute of footage is lost to this error. My wide shots are sharp however, and soon I gather my wits and start checking focus on the subsequent telephoto shots.
Skip notices another tornado forming to the left of the large wedge. For the second time today, two tornadoes are spinning at once, one a skinny rope, one wedge, both in frame, both F4 in strength. It’s hard to judge scale, but they are enormous as they dwarf the power line towers underneath them. A bolt of lightning shot from the larger tornado hits the ground between the two, like an epic battle scene. It was a rare “positive” strike that is more powerful and longer lasting than the garden-variety “negative” strikes. It took a full 17 frames at 30fps to fade. The smaller tornado whips around the larger one at a ground speed of nearly 90 miles per hour. We watch it get swallowed by the larger wedge. Unreal.
The twister gradually moves to our northeast and becomes partially obstructed by higher ground in front of us. Skip suggests we re-position to get a better view. So once again, we hop in the SUV, this time following the tornado, which is to our front and left. The twister is becoming rain-wrapped, and we lose sight of it in the precip haze. Eventually we find a perch on the top of a hill, this time getting a wider view of the storm. The tornado is gone, but we have an amazing view of the rotating cloud structure. I see dirt spinning up underneath, the sign of yet another tornado forming, but the motion disappears quickly. Still, it’s enough for me to count as I keep a tally in my head. I’ve seen 5 tornadoes today.
A196-C002v3 (coming soon)
Other storm chasers park nearby and I recognize John Williamson, whom I had chased with before. It’s always like that with this community, you constantly meet your friends while on the road. John points at a funnel cloud to our west. It is a skinny tail dropping out of a little white puffy. Jennifer snaps a photo and someone remarks, “The parameters are so crazy today, it’s like every cloud gets a tornado!”.
We decide to end the day with a dinner in Sioux City and talk about our adventures. Truly an amazing day. Later in my hotel room, I agonize over footage lost to soft focus, finding it hard to get the proper perspective that I have also captured some amazing images. My heart goes out to the people affected by the storms that hit Pilger and Wakefield. Artbeats will be making a donation to StormAssist whose proceeds go to the victims. Looking back, I am also grateful for Skip Talbot and Jennifer Brindly Ubl for having me along. It won’t be my last trip with you both!
Links:
To view clips: http://www.artbeats.com/storms2014
To view demo reel: http://youtu.be/exxyB6pG60s
http://faceofastorm.blogspot.com/2014/06/twin-tornadoes-in-nebraska-june-16th.html
http://www.skip.cc/chase/
http://stormassist.org/