The Destructive Moore Tornado

[John Olexa]

Thoughts and prayers for the people of Moore & other places affected by todays storms. Man, if I lived in Moore I would have to make sure I built an underground shelter. Today, 1999 and one other time I believe Moore, OK. has been hit hard.

 

[Mike Johnston]

The shear destruction of the Moore tornado deserves its own thread on here. Just the fact of 20 or more school children dead is very sad. It looks like the weather services did all they could to give people warning, but sometimes mother nature is just more powerful than all of our technology. My thoughts and prayers are with the good folks of Oklahoma whose families have been affected by this vicious storm.

 

[JamesCaruso]

It goes without saying that our thoughts and prayers are with those affected. The loss of children is always the most heartbreaking tragedy of all. May God bring peace and comfort to all.

Such powerful outlier storms are fascinating to all of us, and it is that fascination that drives our thirst for knowledge. Chasing is part of that desire for lifelong learning, as is the study and analysis.

To that end, I would like to understand more about the ingredients that came together just right in that area to generate the Moore monster. It seemed that southwest OK nearer the Red River was the more likely area for initiation, closer to the front / dryline intersection. This seemed to be favored by a lot of chasers, and even seemed to be more of a focus in some of the forecast products. Further north was along the front with northwest winds behind it, usually not as appealing as a target area.

There is not much in the target area thread from the morning of this event, so I cannot find any comparisons of potential targets. If anyone chose that area in particular, I am curious as to the factors that led you there. I am also interested in any hindsight/retrospective analysis anyone cares to offer.

Thanks.

 

[Timothy Schaffer]

Wow. Just found these videos.
Possibly a couple of the most unique (and stupid) tornado videos I have ever seen.

Guy trying to get to his son...
http://www.liveleak.com/view?i=6df_1369139249


Filming from a storm cellar...
http://www.liveleak.com/view?i=f79_1369142032

Reed

 

[Damien49]

Radar animated of the supercell that produced the deadly tornado in South Oklahoma City.

source : http://www.wunderground.com/

Very characteristic hook echo. In the center, the purple echo is also characteristic of debris formed by the damage: "debris ball"

Initially the echo is very classic with a bean-shaped echo, then a rotating hook with a very violent classic supercell. Then we can assume that just before it reaches the interstate 35, the supercell took a configuration of HP, with the hook point disappearance and formation of rain clutter completely surrounding the tornado over a large area before take a more conventional configuration, and finally disappear. This is also clearly seen in the videos too.

The Doppler also show that this supercell could theoretically cause other smaller tornadoes, especially near Mustang before and maybe after, but not.

 

[Jeff Duda]

I am personally bewildered at the behavior of that storm. It went from a little shower to violently tornadic so quickly. I'm curious where the vorticity came from to generate such a strong tornado so quickly. The 5000 CAPE in the 17Z OUN sounding likely had something to do with that, but I don't think I've ever witnessed a storm go from shower to producing an EF5 in 45 minutes or so like this storm did.

 

[B Doss]

The damage to the neighborhood leading up the Plaza Towers Elementary School reminds me an awful lot of how Greensburg, KS looked on the morning of 05/05/07. I believe the official death toll has been lowered now, as some bodies were counted twice. I'm not sure if there are still any unaccounted for, and if there are, I'm starting to doubt there is a lot in terms of remains for rescue workers to find. Have someone heard back from Stormtrack members that live in Newcastle-Moore, OK areas?

 

[Derek Weston]

I am personally bewildered at the behavior of that storm. It went from a little shower to violently tornadic so quickly. I'm curious where the vorticity came from to generate such a strong tornado so quickly. The 5000 CAPE in the 17Z OUN sounding likely had something to do with that, but I don't think I've ever witnessed a storm go from shower to producing an EF5 in 45 minutes or so like this storm did.

Right. Hadn't looked at that sounding, but giant CAPE across the region. Yet none of the other storms behaved like this. To me it seemed that the only thing yesterday's setup was lacking was better low level helicity. Wondering if the Moore storm was able to tap into enhanced low level shear in a localized environment that other storms just didn't have.

 

[Derek Weston]

Radar animated of the supercell that produced the deadly tornado in South Oklahoma City.

source : http://www.wunderground.com/

Very characteristic hook echo. In the center, the purple echo is also characteristic of debris formed by the damage: "debris ball"

Initially the echo is very classic with a bean-shaped echo, then a rotating hook with a very violent classic supercell. Then we can assume that just before it reaches the interstate 35, the supercell took a configuration of HP, with the hook point disappearance and formation of rain clutter completely surrounding the tornado over a large area before take a more conventional configuration, and finally disappear. This is also clearly seen in the videos too.

The Doppler also show that this supercell could theoretically cause other smaller tornadoes, especially near Mustang before and maybe after, but not.

Interesting to see it really intensify as it munches the updraft to its south.

 

[John Sickels]

In no way should the following be considered a criticism of SPC, but can someone lay out to a somewhat-informed amateur such as myself why the particular tornado watch that this storm occured in was not a PDS watch? I'm not saying it should have been, but Jeff Duda's comment about the peculiar behavior of the Moore supercell got me thinking about that.

 

[brice.coffer]

I am personally bewildered at the behavior of that storm. It went from a little shower to violently tornadic so quickly. I'm curious where the vorticity came from to generate such a strong tornado so quickly. The 5000 CAPE in the 17Z OUN sounding likely had something to do with that, but I don't think I've ever witnessed a storm go from shower to producing an EF5 in 45 minutes or so like this storm did.

I too was amazed by how quickly the supercell organized, though now that I think about it, there is not much of a dynamical time constraint on tornadogenesis. Twenty minutes is plenty of time for an initiated storm to undergo mesocyclogenesis and the develop of rear flank outflow. All supercells readily produce vertical vorticity at the surface from downdrafts. What separates tornadic supercells from most supercells is the ability of the overlying updraft to rearrange, converge, and stretch lucky downdraft parcels. Without doing any scientific analysis, my guess would be the same as yours. A copious amount of CAPE, especially in the low-levels, made up for lackluster 0-1km shear by accelerating inflow parcels into the updraft.

 

[STexan]

What I noticed about that cell early on as I was watching for both cell elevation (echo tops) and precip is that is had a HUGE elevation but was not raining under it (in it's early stages). Take that for whatever it's worth to you.

 

[Shawn Schuman]

In no way should the following be considered a criticism of SPC, but can someone lay out to a somewhat-informed amateur such as myself why the particular tornado watch that this storm occured in was not a PDS watch? I'm not saying it should have been, but Jeff Duda's comment about the peculiar behavior of the Moore supercell got me thinking about that.

PDS Watches are issued when there is a high degree of confidence for multiple strong to violent tornadoes. I think in yesterday's case it was clear that the environment was somewhat supportive of a strong tornado or two, but it wasn't at all clear that there was an unusually high risk. There was a ton of instability, and shear was certainly good enough, but it wasn't a setup that screamed "violent tornado outbreak." For instance, the 17z OUN sounding showed 0-1km SRH at 131 m[SUP]2[/SUP]s[SUP]2[/SUP] and 0-3km at 156 m[SUP]2[/SUP]s[SUP]2[/SUP]. That's actually substantially below the average for violent tornadoes. That obviously doesn't mean it can't happen, especially with the help of boundaries and other small-scale influences, but it's not really supportive of a PDS-type risk.

 

[PDailey]

Hi-Res Photos: http://www.theatlantic.com/infocus/2013/05/photos-of-tornado-damage-in-moore-oklahoma/100518/

Very close (too close, really)
http://www.youtube.com/watch?feature=player_detailpage&v=-iuGipbmneY

 

[Joe Karel]

I'd like to add some ideas/theories for discussion that have been swirling around in my head since yesterday. Like many things I can only speculate cause and affect. As for initiation, while watching this yesterday the stationary front/dryline intersection was where this cell formed or very close to and the storm itself may have hung close to the stationary front while it moved east northeastward. I would think that would cause greater low level shear/helicity in this area. There was also a cell racing northward into this area before true initiation that may have collided with ongoing CU/the fronts. Not sure if this helped any or may have just been coincidence.

As for why it intensified rapidly and produced what it did, I only have a few things I noticed. Referring to the radar loop in the Reports thread, at the beginning of the loop there was a second cell/hook NNW of the Moore cell that seemed to weaken/merge with the Moore cell. At that very same time the Moore cell sucked in a cell/shower from the south and this is when it rapidly intensified. Now it may have been just coincidence or may have not had any affect but I'd think these two things may have had some affect on the outcome. Again this is all speculation and it'll take some time to do some real analysis but I thought it was interesting. I could be very wrong about a few things so I'm open to other possibilities/corrections/thoughts.

My heart and prayers do go out to everyone in that area also.