May 24, 2011 Oklahoma Tornado Outbreak including Shawnee and El Reno Tornadoes


YouTube Video of Tornado (Original is in HD Video)


chase images and log by William T. Hark, M.D. Video (HD) and pictures available for licensing



This was an exciting, scary and sobering storm chase. I had one good intercept with a tornado near Shawnee, Oklahoma and encounters with the deadly EF 5 El Reno and Piedmont wedge tornado. A tornado outbreak had been predicted for several days. There was a surface low in northwestern Oklahoma at the base of the panhandle and a negatively tilted trough giving broad southwesterly flow across the region. The low was expected to strengthen and shift northeast. Rich moisture was coming up from the Gulf of Mexico with upper 60's and lower 70's dewpoints across the area. I really liked the southeasterly surface and 850mb flow. Expected CAPE values would be 4000 to 4500. There would be backed winds along the dryline and later storm development along and ahead of that boundary. As expected, the SPC issued a high risk for long track violent tornadoes. Storms would form in Kansas and then there would be storms in Oklahoma.

I was initially chasing with Dave Lewison, Scott McPartland, Chris Kridler and Canadians Mark Robinson, Brad Rousseau, Meghan Yeo, Dayna Vettese and Heather Reynolds. We started in Enid, Oklahoma. All of us had initially forecast for north-central Oklahoma. After a quick lunch, we decided to head west but we were already seeing signs of development in southwestern Oklahoma on satellite imagery. Upon additional discussion, we decided to head south and then west. Initiation occurred near Elk City, with an isolated storm. Additional storms were developing to the south. We had driven south on 81, then west on 33. By 2:33 PM, we were in Watonga, Oklahoma. Decision time! The initial storm was just to the northwest while there were more storms forming to the south. At this point, I figured the isolated storm to the north was moving away and may be difficult to intercept while there were better storms to the south. Dave, Scott, Chris and the rest of the group decided to go after the northerly storm. They barely missed the Canton wedge but saw a nice tornado near Fairview from that storm. I headed south from Watonga on 270/281. I took a quick detour west to observe a tornado-warned storm but was not impressed, and I didn't want to be cut off by the more massive storm to the south. I continued south and reached Geary, Oklahoma by 3:25 PM. There was a huge tornadic storm south of I-40 and south of my position. At this point, my Delorme GPS crashed, and I was only using the rough map on ThreatNet and a Rand McNally Atlas. I was worried the storm would turn right (it did but slightly farther north than I expected), and I would be caught on the north side of the storm. I wanted to position just east of it. I drove south to I-40, and then headed south from exit 104 on Methodist Road. The huge dark tornadic storm was rapidly approaching my position from the southwest. At 3:41, I was having difficulty seeing the base due to a low hill. I continued south, then turned west on State Road 37. I still couldn't see the storm base due to a hill. Finally, I had a good visual of the massive storm. Directly to my south at 3:46 PM was a rain-wrapped tornado. I later determined that this was the dissipating stage of the Lookeba, Oklahoma tornado. The storm was moving northeast and threatening to cut off my southerly route. I blasted a bit east, then south on 37 (a continuation of S. Methodist Road). The intensifying storm was approaching my road as I raced to get by it. Wrapping rain curtains overtook me by 3:47 PM and I saw pieces of trees fly across the road toward the west. I was having difficulty seeing to my southwest due to trees. The winds increased and I felt the car move due to those winds. By 3:49 PM, the winds shifted and I turned east. I hit by southerly winds and to the north, I was staring at a giant rain-wrapped wedge tornado. I couldn't see around it and contrast was poor. I stopped at 3:51 and watched power flashes to the north. I was blasted by RFD. I headed east on 37 watching the tornado to the north as it faded into the rain and clouds. The road options were terrible and 77 stair-stepped to the southeast. Unfortunately, I missed a nice north option that lead to the only crossing of the Canadian River until 81 thanks to my GPS failing. I turned east on 152 then north on 81. I blasted north to attempt another intercept. According to radio reports, there was a “maxi-tornado” doing extensive damage north of I-40. It was moving east northeast and would cross the northern side of El Reno. I raced northward on 81 and reached the interstate by 4:27 PM at the El Reno exit. I turned off on S. Shepard Avenue to take a more direct route north. By 4:30PM, I could make out the dark rain-wrapped wedge tornado just to my northwest. I saw more power flashes. I stopped at 4:32 PM and storm was directly to my north. Continuing farther north wouldn't likely improve visibility and there was no decent east option. I also didn't to get caught in the RFD as the tornado moved east. I just watched it for a while as it moved northeast. The violent tornado was taking a direct path toward Piedmont, a populated area that included the home of Rocky and his family. I hoped they would be spared.

12:11 PM CDT Enid, OK

I am driving to the target

WX WORX radar image 3:08 PM

WX WORX radar image 3:08 PM (close)

View to west on 37 at 3:44 PM

View to south on 37 at 3:44 PM
wall cloud visible

View to south from 37 at 3:46 PM
Developing tornado

View to the east from 37 at 3:48 PM
Wedge tornado is north (left of view)
and flying debris crosses road

View to the north from 37 of
rain-wrapped wedge at 3:50 PM

Enhanced view to the north from 37 of
rain-wrapped wedge at 3:53 PM

View to the north from 37 of
rain-wrapped wedge at 3:53 PM

View to north at 4:32 PM of
wedge from S. Sheppard Ave
near El Reno.

Enanced view to north at 4:32 PM of
wedge from S. Sheppard Ave
near El Reno.
. . .

With more tornadic storms approaching from south, I attempted another intercept. I headed east on I-40, then south. There was already a tornado reported near Chickasha. This was rush hour and progress was slow due to rain and traffic. I avoided the limited access highways as my biggest fear was getting trapped in traffic as one these violent tornadoes approached my position. I made it as far as the south side of Norman by 5:48 PM. I was trapped between two tornado-warned storms in very poor visibility. This part of the chase was over. I let the storm to my north pass, and then I headed north and east on I-40. There was a storm approaching from the south, and I had one more chance at an intercept. The presentation on radar was lackluster but I liked the wall cloud to my southeast near Shawnee. I stopped to watch and ran into Chris Collura. Rotation increased and could see an intermittent spinup to the southeast. It increased in size as it shifted northeast. I headed east on I-40 and could see a nice elephant trunk tornado to the east by 6:37 PM. I stopped by mile marker 174 and watched the tornado to my east cross the interstate at 6:38 PM. The bridge in front of me is Ns Co Rd. 330 on the tornado image below. There was a cloud of debris on each side of the interstate as it crossed. I later found out that the second cloud of debris was a truck that was demolished. There was a live view broadcast on television from a nearby helicopter. I approached the tornado and watched it dissipate by 6;39 PM. Visible rotation continued but no more tonadoes. I took exit 186 and headed north on 18 and east on 180/62 tracking the storm. I reached Prague by 7:11PM. At this point, I ended the chase and headed back to Norman. My trip was interrupted by a flat tire that I changed in Shawnee. This was an annoying way to end a wild chase day. I encountered the nasty rain-wrapped El Reno/Piedmont wedge tornado that formed after a handoff from the Lookeba tornado. I was in the middle of that handoff and likely was grazed by the developing circulation of second tornado; one that was later rated as an EF5. I also obtained nice video of the beautiful Shawnee tornado from a safe distance. I was very lucky with my encounter of the developing El Reno tornado and have reassessed my chasing style and the importance of safety. For a high risk day, this was a very difficult chase due to numerous adjacent or “nuisance” storms along with heavy rain wrapping that reduced visibility. This chase was also very sobering due to the terrible devastation caused by the El Reno/Piedmont tornado. Later that evening, I found out that Rocky and his family was safe but many of their neighbors lost their homes.

WX WORX radar image with my position
at 5:48 PM. Stuck between tornadic storms
with poor visibility and traffic

Rotating wall cloud and clear slot at 6:34 PM
view toward the south from I-40

Initial spin up of the Shawnee tornado
view toward the south from I-40 at 6:34 PM

First funnel of the Shawnee
tornado at 6:36 PM. View to the south

I'm filming the tornado from
the shoulder of I-40

Shawnee, Oklahoma tornado 6:38 PM

Nice debris, 6:38 PM

Nice debris, 6:38 PM

6:38 PM

Storm chaser hanging out of their car

Tornado hitting truck with flying
debris at 6:39 PM

Tornado hitting truck with flying
debris at 6:39 PM. Close-up.

Shawnee tornado roping out at 6:39 PM.

Shawnee tornado roping out at 6:39 PM.

My flat tire after the chase.

Archived Outlooks, Weather and Model data

SPC Day 1 13Z outlook graphic & Tornado prob 1300Z SPC Day 1 Conv Outlook; 1630Z;2000Z Tornado Reports Norman NWS Outbreak info
250 mb 1200Z 500 mb 1200Z 850 mb 1200Z Surface Obs 1343Z
Temp/Dew 1300Z SB CAPE 1300Z EHI 1300Z Surface Prog 1800Z
Satellite 1401Z 12Z NAM 850mb 1800Z 12Z NAM 850 mb 0000Z 12Z NAM 500 mb 1800Z
12Z NAM 500mb 0000Z 12Z NAM 700 mb 1800Z 12Z NAM 700 0000Z 12Z NAM Surface Wind/MSLP 1200Z
12Z NAM Surface Wind/MSLP 1800Z 12Z NAM Surface Wind/MSLP 0000Z 12Z NAM Dewpoint 1200Z 12Z NAM Dewpoint 0000Z
12Z NAM Surface CAPE 1800Z 12Z NAM Surface CAPE 0000Z 12Z NAM SRH 1800Z 12Z NAM SRH 0000Z
12Z NAM Precip 1800Z 12Z NAM Precip 0000Z 12Z RUC 850 mb 2100Z 12Z 850 mb 0000Z
12Z RUC 500 mb 2100Z 12Z RUC 500 mb 0000Z 13Z RUC Surface Wind/MSLP 2200Z 13Z RUC Surface Wind/MSLP mb 0100Z
13Z RUC Dewpoint 2200Z 13Z RUC Dewpoint 0100Z 13Z RUC Surface CAPE 2200Z 13Z RUC Surface CAPE 0100
13Z RUC SRH 2200Z 13Z RUC SRH 0100Z 13Z RUC Precip 1500Z 13Z RUC Precip 2200Z
13Z RUC Precip 0100Z WRF mxuphl 2300 V023 and 0000 V024 WRF Reflectivity 20 hr,21 hr,22 hr, 23 hr,24 hr,25 hr MCD discussion + graphic

Go to May 25 - 29 , 2011 Storm Chases

All images Copyright 2011 William T. Hark