My Original Target Area Forecast
Posted 3/29 

This chase was a pretty focused and concentrated one, and was just a tad further south than I had initially expected. We left KC Sunday morning and headed to NW Oklahoma in the Alva to Fairview OK area. The deeper instability and warm front kept trending further south on the RUC on the day of the chase so we adjusted our target further south along the I-40 corridor. After a relaxed lunch at the Cherokee OK Pizza Hut....we decided that it would be wise to head down towards I-40. The RUC began to lock into the forecasted development of supercells down that way by early evening. As we got further down towards Custer County and eventually to I-40, multiple severe storms and developing supercells had flared up all along I-40 from west of El Reno west and southwest towards the Elk City - Mangum area. We decided to commit to a very strong supercell that was seemingly anchored down in the Retrop area of extreme SW Washita Co. Hail to baseball sized was mentioned in the warning for this sluggishly moving supercell. We plotted an intercept in/near the town of Sentinel so made our way southward from I-40. We encountered some golfball sized hail as we neared the town of Sentinel, and were a bit concerned we may have a shattered windshield before we could get to the main updraft. Fortunately, the main hail core eased east of the highway as we moved into Sentinel. On the south side of town, the updraft base came into view. Although it was a bit high based, the strong rotation was very evident. A strong RFD notch was seen as well as the pre-tornadic cascading rain curtains swirling around the center of circulation about 2 miles southeast of Sentinel. We watched this slow moving updraft for nearly 15 mins. and we could tell that although a tornado was not imminent, the base had to be watched closely. A tornado warning quickly was issued by the NWS Norman, and Jeff called and said it had a TVS on radar. The part that probably kept this tornado from actually occurring was the splitting of of a left mover updraft piece off the main updraft. This seemed to disrupt the overall strong circulation. A high based funnel lasted about 2 mins. almost overhead and just to the right of the large RFD region. This was not a threatening situation so we held our ground. 

We watched the updraft from the backside until it moved further to the east and towards the small town of Rocky. We headed east on OK-55 towards Rocky and kept the relatively flat rain free base in view the whole time. We found lots of big hail west of Rocky with the largest short spiked hailstone measuring 3.5". Lots of golfball and tennis ball sized hail was found about 2-3 miles west of the town of Rocky. We followed the supercell into Caddo Co. but could not get to the updraft area near Albert without getting hammered by the hailcore. We decided to head into Binger, and wait for the second t-warned supercell that was moving out of E. Washita Co. and would pass north of Binger. We stopped in Binger at the local car wash and watched an amusing period of chasers going all directions....some seemingly confused whether to stay with the lead supercell moving towards the town of Cogar....or the second nasty potentially tornadic supercell moving east near the Colony OK area. We decided to head north and try to get a glimpse of the tornado that was reported near Lookeba. The circulation looked quite low and strong, but certainly more HP than hoped for. A large RFD region core had wrapped around the main updraft, and unfortunately hid the "area of interest" from our view. We decided to head east and try to find a better vantage point. Near the town of Cogar, met Tony Laubach for a brief moment before the southern part of the core hit. None of us were able to see the tornado that had been reported near Lookeba earlier. We could see a pretty serious arcus moving in, so we decided to high-tail it east and get well ahead of the updraft and hailcore. We took shelter in Union City just as the tornado sirens fired up in town. We found a gas station overhang to seek shelter from the advancing core. Just as we got under shelter, the nickel and quarter sized hail had transitioned to up to golfballs and the hail was hitting the pavement very hard. We watched as the golfballs became sporadically mixed with 2-3" hailstones that smacked the pavement. The tell-tale sign of the roaring hailcore was soon upon Union City. It did appear that the circulation had gusted out because we could see a sizeable arcus cloud passing over town...and really the inflow was much weaker than the outflow that eventually slammed in with a secondary shot of heavy rain and quarter sized hail. Radar trends showed this large supercell had blasted out, and all circulations had dramatically weakened. We felt safe to leave the overhang and decided to head on into OKC and find a hotel to bunk down for the night...or so we thought !!

We felt that the target zone for Monday was still a bit undetermined, so we headed on to the northeast side of OKC and looked for a hotel room there. As we searched, the radio seriously came alive with reports that the supercell was starting to rotate strongly again on the NW side of OKC. We listened and were stunned that a tornado warning was dropped for the late night supercell. We were in the Sleep Inn parking lot getting forecast data when the winds began to roar from the east...a solid 45mph with a few gusts well into the 55-60mph range. This was certainly eye opening to us. We were in position to nail whatever was coming up towards I-35 from the southwest, so we decided to head north of Edmond. Quite a few chase vehicles also were blasting north on I-35 and towards the approaching circulation. We could see occasional power flashes to our northwest, and this matched up well with the tornado reports from spotters/chasers closer to the circulation. I plotted the track of the supercell's path and it was headed north of the Oklahoma-Logan Co. line and eventually would cross I-35. Although lightning was sporadic at best, we could see some very violent east to west motion on the cigar inflow band, as well as what appeared to be a very tightly wound bowl lowering north of Waterloo Rd. and west of I-35. A few flashes of cg lightning showed a small cone funnel about halfway down and tucked up against the inflow band on the north side of the bowl. There were very occasional power flashes in the vicinity of this small funnel as it moved north-northeast, and a backside rain core soon rotated towards I-35, and soon cut off our pretty decent view of the updraft. We decided to call it a chase as it crossed I-35 and a massive heavy core blasted in. We got into the hotel pretty blitzed, but were happy we got the late night bonus of the small tornado southeast of the small town of Seward (Logan Co.) in the Coltrane-Simpson Rd. area. The chase was pretty decent for a SLIGHT risk, and were quite happy with the great structure views we got before dark...in addition to seeing very large hail and no windshield damage to boot !! One other thing of note, used Weather Underground radar data with pretty good success this chase, and have also become very impressed with Weather Tap's radar stuff too. The chase expenses (GA$ - grrrrrrr) probably will keep us from having Threat Net available this spring. 

Chase Partners: Rich and Ryan Thies
Slight Risk...Tornado Watch

Tornado Warnings and Counties Chased: 
Washita, Caddo, Canadian, Oklahoma, and Logan OK

Special thanks to Jeff & Kathryn Piotrowski for radar updates during this chase.

Looking southeast from south side of Sentinel
(S. Washita Co. OK)
Tornado warning issued for Washita Co., and
Strengthening TVS on FDR Radar Indicated

High Based Funnel 
Looking nearly overhead and immediately east/southeast of Sentinel
Funnel was on occluding updraft area and near the area where
left split occurred minutes earlier

Supercell Updraft Moving East
Looking east from south side of Sentinel
Structure looks pretty classic at this point, but still a bit high based

Classic flat rain free base
Looking east towards Rocky OK
(Washita Co. OK)
Note: large quantity of golfball/tennis ball sized hail
in foreground of this photo

Very large hail collected 2-3 miles west of Rocky OK
Largest hailstone measured 3.5" in diameter was found
just south of the road (OK Highway 55)
(Washita Co. OK)

Pretty supercell photos after sunset
Looking northwest towards Burns Flat supercell