Big Hailstorm, Tornado, and D-Magazine 5-29-2012

This was the first day of a two day severe weather event that we chased.
Unlike how the next days forecast would turn out this days was actually pretty good. Primarily because the models did a fairly good job and I had actually been looking over things carefully.

Chased with Justin Terveen, James Langford and Krista Higbee. Krista came on behalf of D-Magazine which was really neat. Hopefully I didn't say anything too stupid. ;)

The day and the next would be characterized by broad upper level flow across the central U.S. While not overly powerful it seemed as if it would provide enough deep layer shear for supercell thunderstorms. Around 35kts of shear, as it turns out, certainly ended up being plenty. Instability wouldn't be a problem either as it maxed out at about 4,000 j/kg near the Wotonga/Kingfisher area.

The Actual Sounding from Oklahoma City at 7pm only indicates ~3,000 j/kg and 33kts. Mesoanalysis on the SPC site would indicate 40kts or so with nearly 4,000 j/kg. 

OKC sounding 7pm

SBCAPE 6pm

0-6km Shear 6pm

The primary focus for storms would be a frontal boundary draped across the northern portion of Oklahoma a dryline to the west and strong convergence near the center of the surface low. In addition a disturbance would be rippling through the mid-level flow providing for additional lift.

The target area was essentially Watonga to Woodward Oklahoma. An area that was fairly close to the surface low and with surface winds backed to the southeast rather than south. This would enhance the overall shear and helicity just a bit more despite the lack of low level shear. Winds up to about 3km were pretty much aligned with only a bit of speed shear. So tornadoes were not really something I was expecting.

However, supercell thunderstorms in the right environment that latch onto boundaries or experience odd interactions with nearby cells may not care that low level shear is weak. This has been a well noted fact and why many chasers want to see a supercell thunderstorm interact with some kind of boundary. It all has to do with how winds change on a boundary and how low level shear and helicity might be considerably higher in the inflow region of a storm that is interacting with a boundary.

The reason I bring this up is because the storm that impacted the Kingfisher/Piedmont area produced a tornado (more than one?) despite the lack of low level shear and helicity after colliding with the outflow from another powerful storm to its south. What an incredible meteorological phenomenon that was to watch! Both storms then quickly fell apart after ingesting each others outflow. 

We left James' house around 11:00am and headed north on I 35 while giving Krista the Severe Weather 101 lesson which is really a condensed version of a skywarn class I guess. (Shear, Instability, and Lift)

Once on I 40 we teamed up with the DOW (Doppler On Wheels)... or more like passed them. It was, however, encouraging to see them heading the same direction we were.

We arrived just north of Watonga around 3pm and waited for storms to initiate. This consisted primarily of watching puffy cumulus clouds get bigger and bigger while we were getting sunburned. Finally noted some high clouds on the horizon just after 4pm associated with a beefy area of cumulus and assumed storms were firing.

The storms were slow moving and yielded some incredible explosive updraft motions. For a time we were able to sit under the developing mesocyclone as it organized near the town of Okeene while spitting some penny to nickle sized hail at us. This storm was also the southern most cell in a line of storms and therefore had the least obstructed inflow out of all of them.

The storm passed just to the northwest of Okeene by only a few miles. Interestingly the sirens in Okeene were blowing and we never knew the reason for it. The storm was high based at the time and there was no wall cloud (though mid level rotation was quite strong). There appeared to be some smoke in the town and perhaps a fire was the cause. Also, a number of dry microbursts were noted just north of town where the RFD was likely taking shape.

We were really cut off at Okeene since the storm was moving southeast right over highway 51 and there were no decent roads to take to the southeast to stay with the storm. Core punching was not really an option for those of us who dislike being beaten with large hail. We could've stayed on dirt roads but that is always a bit risky. We decided to drop south on highway 8 and then find another eastbound option.
I believe that eastbound option was Loyal Road as it was the only paved option and I don't even believe it was paved the entire way.

Whatever the road we took it east a little ways and that is when the storm started developing wall clouds. The first few were exciting... but not terribly exciting. (Actually most wall clouds for us are terribly exciting.) But with each wall cloud the storm would cycle through they would get lower and rotation would become stronger. In fact, the rotation at several points became very pronounced and very close to the tornadic storms I could compare it to. It really makes me wonder if it would've eventually put down a tornado anyway as it continued on into deeper moisture while surface temps cooled a bit in the evening. But we will never know since the storm collision of awesomeness took place at the critical "magic hour".

The first Wall Cloud by Justin

Another Wall Cloud by Justin

Wall Cloud image by James Langford

We dropped south out of Loyal to highway 3/33 and headed east into Kingfisher. It was about at this point that the storm was producing the Softball to Grape Fruit sized hail. Certainly not a storm we wanted to be cored by. We didn't really have time to stop as we barely made it through town before the storm as it was. Inflow was very impressive as well.

 

There was another cell immediately two our south that we had noticed earlier in the day. Not entirely sure where it originated, but it was likely a left split off of some storms closer to the Red River. It shot north at a fairly high rate of speed and was essentially on a collision course with our cell. The updrafts were extremely impressive with this cell as it came towards us. The situation was somewhat problematic for us because it looked as if we would be caught between the cells as they collided. Thankfully we were able to stop on the south side of Piedmont and just watch the process unfold.

The sky was simply crazy with stuff going on. We had the original cell to the north which was sucking in the outflow from the southern cell coming north and this made for tremendous wind at our location (tremendous being 40-50mph). We didn't have a great view of the southern cell as it merged given its meso was somewhat hidden at the angle we vied it from (the tail end of the RFD region I guess). So, we were most interested in the meso to our north on the original storm.

I can't really describe it but James' and Justin's pictures do a pretty good job.

Picture from James of the mesocyclone containing the developing tornado

Picture from Justin of the mesocyclone

Panoramic Image of the Mesocyclone from James

Panoramic Image of the Mesocyclone from Justin

There were actually a few areas of strong rotation, but the main circulation that the rain was wrapping around right in front of us produced the only known tornado.

Video of the tornado by James

Photo of the Tornado by Justin

The tornado was very brief but surprising to me. I had seen the circulation wrap up earlier and thought that it was done given that it appeared to have completely occluded. But the rain thinned out for a moment and there the funnel was! Thankfully it was brief and there was very little if any damage.

Another interesting point is that as this process unfolded the storm base seems to have raised. Likely due to the updrafts being chocked to some extent and the storm weakening. But it was right at the end of that that the tornado appeared.

The above radar loop should tell the rest of the story. The cells merged and spun up then immediately collapsed after ingesting each others cold outflow. We then had to find a way to get out of Piedmont and back south as another supercell quickly blew up on the outflow boundary set down by the original storm we  were chasing.

We managed to make one stop in Union City for lighting on this new cell before having to flee to the south again. At that stop there happened to be a civil defense siren not more than 50 feet from us. A tornado warning was issued for this new storm and the siren went off. I really didn't know how load those things were until now. As it made its sweep towards us the ground actually was vibrating.

New Cell Mesocyclone by Justin

Some lightning out of the Meso by James. Possibly from a different stop. 

Another from Justin

The day ended after a quick gas up stop which was cut short thanks to the new monster storm sneaking up on us quicker than expected. Given the 75mph plus winds expected with it along with the huge hail we figured we didn't need a full tank.

We quickly got back on I 35 and took it back home to Dallas where the large complex of storms eventually had an impact later that night.

In looking back all I can say is wow. The one day that we get somebody from D-Magazine to come along is the day that the forecast actually verifies and everything down to a tornado is witnessed. Wish I could say that my great forecasting skills was to be blamed for this but it isn't really. While I might have some (that God gave me) I am not the one who controls the weather. 

Texas Dusteater 5-30-2012

Haven't taken the time to write many chase accounts this year though there have been more successful chases this year than last. There are more important things in life than spending a few hours trying to recount every last detail of a storm event. :) And there have just been so many!

I guess I'll start with the most recent chase and then work backwards if I have the time to do other chase event right ups.

 This was day two of a two day chasing marathon. God in his grace allowed us to see some amazing stuff. Just glimpses of his power and glory that he has placed in creation. It really is a wonder that things worked out so well given the difficulties that come with trying to forecast thunderstorms. Every photograph is a gift from the creator and we should be so thankful that we walked away with such awesome photographs. Many would say we should be thankful that we even walked away. ;) And I really should agree given the dangers of the road. Actually, in reality, we should be thankful for every moment of everyday as it is a gift from the creator. And we should be thankful that the storms didn't cause anymore damage than they did. Both the 29th and 30th yielded some EXTREMELY severe storms. 

While the previous day's forecast  (the 29th) was spot on with storm initiation and progression almost as expected, this days forecast (the 30th) was garbage. Part of the problem was not looking over model data before heading out. I didn't think we would actually be heading out since Justin was suffering from suspected food poisoning. He woke up and insisted that he felt alright enough to chase and so we did. But, I didn't bother looking over model data beforehand and just ran with the SPC's forecast figuring that this day would wind up much like the previous day.

The Storm Prediction Center had issued a Moderate Risk for a large portion of Oklahoma. It looked as if a cluster of supercell thunderstorms would erupt north west of Oklahoma City (much like the previous day) and then progress southeast while transitioning to a mesoscale convective system capable of producing widespread wind damage.

As we shot north on I 35 towards Oklahoma City there were a few disturbing things about my Northwest Oklahoma target:

1. The dry line was much further west than I originally thought (models had started showing that way earlier) and the cold front was stretched east to west in Northern Kansas (something else the models had certainly picked up on that morning).

2. Instability was weak and declining near my target area, but very high in the Eastern Texas Panhandle, Southwest Oklahoma, and down into Northwest Texas.

3. A very sharp boundary existed in Northwest Texas near Childress/Vernon where nearly 6,000 j/kg of CAPE had pooled along with some very strong  wind shear.

Perhaps we needed to change target areas?

However, in the past we have often come to the conclusion that one should never be quick to give up their original target area. Given that SPC kept the moderate risk over Oklahoma surely meant that at some point things were going to get interesting right?

I simply hoped that we could get storms to initiate somewhere near Nokona or Woodward Oklahoma along what seemed to be some outflow boundaries. That and that alone would likely be our only play.

Well once we got going west on I 40 out of OKC things were becoming pretty clear that we had just made a big mistake.

This outlook is only slightly different than the original. If anything it is simply bigger. The real difference was in the text. And it wasn't too terribly different.

 EARLIER THOUGHTS REGARDING THE EVOLUTION OF CNTRL/SRN PLAINS
 CONVECTION REMAIN.  LATEST OA FIELDS SUGGEST AIRMASS ALONG THE I-70
 CORRIDOR ACROSS KS IS DESTABILIZING SIGNIFICANTLY WITH SFC-3KM LAPSE
 RATES NOW APPROACHING DRY ADIABATIC.  FOR THIS REASON IT APPEARS
 CONVECTION SHOULD DEVELOP AND INTENSIFY ALONG NRN PLUME OF
 MOISTURE/INSTABILITY AXIS OVER THE NEXT FEW HOURS.  WITH TIME ONE OR
 MORE MCS-TYPE STRUCTURES SHOULD EVOLVE ACROSS NWRN KS WITH
 SUBSEQUENT SEWD MOVEMENT INTO OK EXPECTED AFTER DARK AS LLJ
 INCREASES ACROSS THIS REGION.  HAVE OPTED TO LOWER THE TORNADO PROBS
 ACROSS SRN KS/NRN OK DUE TO THE EXPECTED MCS STORM MODE.

That is what the models had been showing ever since the early morning hours. Crud. Central Kansas looked like it was going to be the place and the main bulk of Oklahoma would not be seeing storms until after dark (yuck) once the storms had organized into "one or more MCS-type structures".

Well... what to do now?

Turns out that there was a sharp boundary likely set down by the previous day's MCS running from the dry line in the Eastern Texas Panhandle through Childress towards Wichita Falls. Shear was quite high down there as a fairly decent jet streak sat over the Red River valley region. The cap was not much of an issue in Texas thanks to the fact that the mid-level shortwave was pretty strong. (Or it seemed to be fairly strong and far south). Nearly 6,000 j/kg of CAPE had pooled along that outflow boundary.
This is where the show would wind up being. And I had been ignoring it all day thanks to my stubborn SPC watching and not taking the time to carefully evaluate things in Texas.

Thunderstorms quickly erupted in the Eastern Texas Panhandle down the dry line to about Childress Texas. At that point I had considered simply heading home since we were so far out of position. However, the storms in Texas were tempting and if we kept west on I 40 we would gradually approach them.

James Langford called and seemed to think we should try and make a move towards the storms in Northwest Texas near Childress. Seemed like it would be worth a shot given how far we had already come. The cell on the southern end of the line near Childress looked like it would be the most healthy given it had unobstructed inflow and did not have to deal with splitting cell collisions that cells within the line did. The general easterly motion to the storms would make things easier given how far west they were from us.

The tricky part would be how to get south to the ones near the Red River. We decided to take Highway 6 south out of Elk City Oklahoma to get into the path of the storm near Childress. Things looked promising. And then a couple of things happened with the storm of interest. It began to dive south-southeast rather than moving more east, and a new storm formed to its southeast potentially causing some inflow problems. Our new target would have to be this new cell that was now at the southern end and it was now diving south-southeast as well. The only good thing seemed to be how slow the storms were moving. 

Thankfully Justin and I were pretty relaxed today and didn't really feel the need to see anything too spectacular given how well the previous day had gone. So, the drive south was not really stressful. In fact, we were treated to some awesome looking clouds and lightning on our way south. The storms to the west had generated tons of anvil blow off that began to cover the western side of Oklahoma. In addition we came across some amazing cloud streets once we got south of Elk City. They had likely been there all day given the visible satellite presentation throughout the day. Note some mammatus in the anvil blow off from the western thunderstorms. 

In addition we encountered some high based storms in Southwest Oklahoma that were very poorly organized but produced some incredible cloud to ground lightning. We had a number of close strikes. It made the drive much more interesting. Once we got south of those storms we were treated to an incredible atmospheric display in the anvil blow off from the storms we were trying to pursue. Contrast was high and the atmosphere clear and the mammatus/virga combination was really pretty. Large positive cloud to ground strikes were randomly hitting all around us. It was very surreal. The fires that we drove past added to the affect. They were likely set off by the lightning.

The storm of interest was very near Crowell Texas once we got to the Red River which must've been around 6pm. At that time it was a gigantic supercell with a gigantic mesocyclone. The storm itself wouldn't have quite fit into Collin County! The mesocyclone itself must've been 5-6 miles across or more.

I had a difficult time picking the roads to get us in its path. There were not as many highways as I would've liked down there and we needed to be far enough ahead of the storm that we would have time to escape to the south and east if we needed to.

Wound up staying on 283 south out of Vernon Texas and then taking 277 southwest out of Symour to get us into the storms path. When we reached Goree Texas we took FM 266 about a mile or so north of town.

At this point we were in the middle of the supercells inflow jet. I thought winds were sustained at around 45-50mph with gusts to 60mph. Most other chasers figured winds of 40-50mph. Whatever the speed it was WINDY and the dust being kicked up was quite a lot. We stayed just south of some dirt fields that were kicking up the most dust in order to stay out of the mess.

The storm that came into view was not like any of the other supercells I had personally seen before. I had seen some storms in photographs that had the swirly/babarpole/striations all the way up through the anvil but never in person. Given the inflow that was kicking us all around as we tried to hold our tripods steady and the massive vortex of a storm heading right for us I'd have to say this was one of the more intimidating moments in chasing. Maybe not the most but certainly up in the top few for me.

This was the last image taken from this spot and the edge of the meso is just about to us. This was shot with a 10mm lens on James' 30d. Can't remember the number of vertically oriented shots made to stitch this but it was a number. Point being is that the storm looks a lot smaller in the picture than it really was. The top part of the photograph was practically overhead for reference. 

We made a quick retreat south on 266 to stay ahead of the storm. Goree was blowing the sirens as there was a tornado warning in progress. Softball sized hail had also been reported.

Once we got south of town we played leapfrog with the College of DuPage storm research team. The dust eating storm began to weaken towards 8:00pm which caused it to stop dropping south and it moved more east again. We had an incredible view now that we were well ahead of it. Here the meso and mammatus swirling around it can be seen.

What an awesome sky. I don't think words or even photo's quite do it justice. 

We did shoot lightning later though I haven't processed those shots yet. I might add them to this set later.

We headed home on 380 with wind and heavy thunderstorms to keep the drive home interesting. White knuckle drives are always better for keeping one awake. Easy for me to say of course given that I wasn't driving.

Speaking of which, thanks Justin for driving and taking us all over the place. And thanks James for the advice and the use of your Canon 30D which, by the way, is the only reason I have ANY pictures from this day.

Justin has an awesome set of images on his Flickr page if you are interested in checking his stuff out.