The Destructive Moore Tornado

[Travis Davis]

Here is a radar of pretty much the event.


1855 - 2033 Radar

2038-2215

 

[Steve Mirsky]

Our storm team picture of Moore Oklahoma tornado. Taken from about 3 miles away. At the closest point we were 1.8 miles away.

 

[Logan Karsten]

Ok, after looking at things a little further, here's my thoughts.....

It's quite obvious that the dryline/cold front intersection was Southwest of the OKC region. I would say that the initial convection was dryline forced, leading to the initial discrete supercell storm structure. Now, as a chaser, I would automatically assume that a supercell that interacts with a cold front leads to instant line out. However, looking at the surface observations, it was quite warm/humid behind the boundary. Now, as I loop through the radar imagery, it appears that it is not until the boundary gets close to the supercell that it goes crazy with tornado genesis. Perhaps the low-level vorticity was enhanced by the boundary, leading to rapid intensification of the mesocyclone, and intense tornado genesis. However, since the air parcels behind the boundary were still warm and moist, this did weaken the low-level thermodynamic characteristics of the storm. Either way, it would appear that it wasn't your classic Oklahoma dryline tornado, and it was extremely difficult to foresee or forecast. It is a stark reminder of how boundary interactions can sometimes lead to intense tornado formation, given the right thermodynamic fields. Had the air behind the boundary been slightly cooler or drier, I would have expected things to turn out much differently. Also note that once the tornado formed, the supercell turned right, and began to drift away from the cold front/boundary, and that was when it weakened. Perhaps the mesocyclone began to move away from the vorticity it was ingesting from the boundary, leading to a weakening. Otherwise, I have no other explanation for what occurred. I will leave that up to those with much more knowledge on tornadoes and severe weather than I possess.

 

[Hannah.Taylor]

How does one who witnessed this first hand recover? I have seen a lot of violent tornadoes on tv but never with my own eyes.

I saw the damage in Joplin firsthand two years ago, but I didnt see that tornado or see it in action.

I was with Marcus Diaz, James Siler and Brady Kendrick last Monday when chasing the Moore tornado. The Moore tornado is only the second tornado I have ever seen. When I saw it, my adrenaline was so high and my excitement was so high I was celebratory and ecstatic. I was in a two year slump of not seeing any, and the previous two days of chasing had left me empty handed. Everyone else in our chase vehicle was numb and in shock. Looking back I feel really bad about being excited. The magnitude of what I was seeing didnt sink in till the end of the next day. Even a week later, I am still struggling with what happened. I didnt even have it in me to go chase Friday in Eastern, CO.

I have never forgotten what I saw in Joplin...just the damage itself was of enormous weight. This time I saw the tornado in Moore, but didnt see the damage in person afterwards. I just couldnt. I still have nightmares about Joplin, and I dont know if you ever truely get over it or recover, but I think most of us find a way to manage it or cope with it in our ways.

 

[Brian McKibben]

There are two things that I have been wondering about with this tornado. 1. The problems with the tornado rating system. 2. While reviewing the track it looks like it was beginning to die and then ramped up again near I-35.

I will start with #2.

I have been through the area just east of 35 several times while help with the clean up effort. The damage their is catastrophic, but it is very narrow. Then I found this link from NWS Norman:
http://google.org/crisismap/2013-ok...=CUSTOM&layers=9,7,11,8,layer2,layer11,10:100
While looking through this in a zoomed out view you can notice that after the tornado hit Plaza Towers, it began to move NE and somewhat N. Then, right about 4th st and Telephone road, the tornado turn just S of East. From this point on the damage path is much narrower, although still EF-4 for a while. I find it interesting that the tornado was headed on the NE then North path, which we see when many mesocylones begin to become occluded. I would have expected that meso to die while another one formed to the southeast. However, the tornado/meso survived and then went on for another 5-6 miles. Has anyone else noticed this?

Now for #1. On my old street (SW 149th Pl) most of the houses between 149th Pl and SW 149th St were destroyed. Not wiped clean but, they were destroyed. The houses of the other side of the street fared better. However, some of them got hit pretty bad. In fact, some even further south got hit pretty bad.

Here is the problem I see with the damage scale. I think the reason why some of the houses further into the neighborhood got hit was because they got hit by some debris. Once that debris damaged the house and exposed the interior, there became more drag, thus the house suffered significantly more damage than the one right next to it. This made two houses sided by side look drastically different. One would have EF-3 while the other would be low EF-1. I doubt the winds were significantly different 20 feet away (especially oriented East to West), so the damage was likely caused by debris.

A tornado with a significant debris cloud would likely cause more damage than one with out it. Therefore, a weaker tornado in an urban area will cause more widespread damage than a stronger tornado in a rural area.

I know the rating scale is inaccurate. This is just one of the many problems with it.

I wonder if anyone had a mobile radar sampling this storm?

 

[Jeff Duda]

There are two things that I have been wondering about with this tornado. 1. The problems with the tornado rating system. 2. While reviewing the track it looks like it was beginning to die and then ramped up again near I-35.

I will start with #2.

I have been through the area just east of 35 several times while help with the clean up effort. The damage their is catastrophic, but it is very narrow. Then I found this link from NWS Norman:
http://google.org/crisismap/2013-ok...=CUSTOM&layers=9,7,11,8,layer2,layer11,10:100
While looking through this in a zoomed out view you can notice that after the tornado hit Plaza Towers, it began to move NE and somewhat N. Then, right about 4th st and Telephone road, the tornado turn just S of East. From this point on the damage path is much narrower, although still EF-4 for a while. I find it interesting that the tornado was headed on the NE then North path, which we see when many mesocylones begin to become occluded. I would have expected that meso to die while another one formed to the southeast. However, the tornado/meso survived and then went on for another 5-6 miles. Has anyone else noticed this?

Look up the term "cycloid". A tornado rotating about a mesocyclone could easily follow the path of a cycloid, which would feature a gradual veer left with occasional hard right turns. It's entirely possible this is what happened. Also, internal RFD surges could push the tornado out and away from the storm, which would be in a generally southerly or easterly direction. The tornado did cycle through being clearly visible and being rain-wrapped, and it appeared to become rain-wrapped as it approached I-35. Wobbles in size and strength over that short a distance may not always be related to mesocyclonic processes.

Now for #1. On my old street (SW 149th Pl) most of the houses between 149th Pl and SW 149th St were destroyed. Not wiped clean but, they were destroyed. The houses of the other side of the street fared better. However, some of them got hit pretty bad. In fact, some even further south got hit pretty bad.

Here is the problem I see with the damage scale. I think the reason why some of the houses further into the neighborhood got hit was because they got hit by some debris. Once that debris damaged the house and exposed the interior, there became more drag, thus the house suffered significantly more damage than the one right next to it. This made two houses sided by side look drastically different. One would have EF-3 while the other would be low EF-1. I doubt the winds were significantly different 20 feet away (especially oriented East to West), so the damage was likely caused by debris.

A tornado with a significant debris cloud would likely cause more damage than one with out it. Therefore, a weaker tornado in an urban area will cause more widespread damage than a stronger tornado in a rural area.

I know the rating scale is inaccurate. This is just one of the many problems with it.

I wonder if anyone had a mobile radar sampling this storm?

The EF-scale was not designed specifically to be a wind speed scale, although it was supposed to be in better agreement between wind speeds and damage than the original F-scale. The EF-scale is primarily a damage scale, which is why some tornadoes that appear to be mile-wide wedges with violent motion may end up getting rated EF0 (because they caused no damage). The EF-scale was also not designed to distinguish between the causes of damage, so it doesn't really matter if debris or wind alone caused damage. Also, lots of tornadoes have suction vortices which has been shown many times to result in the spatial variability in damage you described. The fact that flying debris may have been responsible for one house getting demolished and wind alone responsible for another is irrelevant, I think.

 

[Mike Smith]

I'm a little perplexed by everyone talking about Moore as an especially fast tornado intensification. For comparison, here is a timeline for Joplin:

• 5:32pm, no known tornado
• 5:33-5:34pm, tornado touches down
• 5:41pm: F-4 tornado, eight minutes from earliest touchdown
• 5:42pm: F-5 tornado, nine minutes from earliest touchdown

Now, I realize Joplin was exceptionally fast. That said, seventeen minutes (if that is what it was) from touchdown to F-4 in Moore doesn't seem especially fast given the F-4 and F-5's I have reviewed over the last decade.

If I am missing something or there is a climatology of which I'm not aware, please illuminate me.

 

[Shane Adams]

I'm a little perplexed by everyone talking about Moore as an especially fast tornado intensification. For comparison, here is a timeline for Joplin:

• 5:32pm, no known tornado
• 5:33-5:34pm, tornado touches down
• 5:41pm: F-4 tornado, eight minutes from earliest touchdown
• 5:42pm: F-5 tornado, nine minutes from earliest touchdown

Now, I realize Joplin was exceptionally fast. That said, seventeen minutes (if that is what it was) from touchdown to F-4 in Moore doesn't seem especially fast given the F-4 and F-5's I have reviewed over the last decade.

If I am missing something or there is a climatology of which I'm not aware, please illuminate me.

Who said it was 17 minutes for the tornado to intensify to EF4 strength? Was there a doppler on wheels timing it while scanning the tornado? I've seen a lot of angles of this tornado and it seemed to go from a small cone to a violent stovepipe in a few minutes. Unless we're just splitting hairs, I fail to see why you're questioning this.

 

[Jeff Duda]

According to information on OUN's page about the event (http://www.srh.noaa.gov/oun/?n=events-20130520), the tornado touched down at 2:56 PM, and, according to the radar overview (http://www.srh.noaa.gov/oun/?n=events-20130520-radar-timeline), was already doing EF-4 damage in a subdivision near Newcastle (just north of state highway 37 and west of I-44) by 2:59 PM. That's three minutes from touchdown to EF-4 damage.

 

[Sean Ramsey]

For what it's worth, here's what I captured and how quickly it grew from the backside on Highway 37 in Newcastle (some photos not processed)....
This is the wall cloud around 2:45 or so:

13 minutes later....

Less than a minute later....

21 Seconds later

 

[Hannah.Taylor]

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.

Jeff if you remember the Joplin tornado developed with the same frightening speed. Going from a small rope tornado to a violent rotating wedge in just 36 seconds. This storm had good structure in Parsons, KS, it just couldn't get it's act together until it crossed into a more unstable air mass on the Missouri side, and then it was like that thing hit 6th gear and was off to the races.

Watch video >

 

[Brian McKibben]

Question...

Both the 1999 and 2013 tornadoes that went through Moore produced F-5/EF-5 damage in Oklahoma City limits. So, should these be referred to as Oklahoma City F-5/EF-5 tornadoes? Or is it correct to say that Moore was hit by an F-5/EF-5 since it was within the Moore school district?


Just saw this for the 1999 tornado... F5 damage was found in Moore. But the question is still valid for 2013.

"Maximum damage, rated high F4/low F5, extended northeast to near Janeway with several large groups of homes flattened."
http://www.srh.noaa.gov/oun/?n=events-19990503-storma

 

[Jeff Wright]

I remember in one of the chopper videos (man I hate digital camera footage with all the blooming and pixelation) which showed a whole row of slabs swept cleean right in front of the school.

In the April 8, 1998 Oak Grove Birmingham Alabama F-5 tornado (among the last as rated before the EF system) hallways were filled with Concrete blocks, where students were in the gym under bleachers and survived (after school)

I would think that both outer and inner Masonry walls need the bed-liner coatings to keep debris down and to help integrity.

I also seem to remember hail bubbles being sold to car owners: http://www.kten.com/story/20537296/north-texas-man-invents

Now in some schools you have inflatable planetariums: http://starlab.com/

So I was struck with the idea of having a combination of the two inflated inside school hallways so as to spread out any debris loads.

These would be tied down to pegs to prevent them from acting as a sail if the roof comes off. The walls would be coated with bedliners may behave similarly, but having the school walls wedge shaped should help keep walls intact.

The hail/planetarium bubbles may even be cheaper than the bed-liner coatings. That may make all the difference and will keep us from having to pay for schools that have to be built like Inman embassies.

Now just going on appearance, Moore '99 seemed more intense.

 

[E. Clark]

A study of the Jarrell Tx 97 tornado would possibly be comparative.

Edit: Found a good study on low shear / high CAPE tornadogenesis specifically referring to the Jarrell '97 tornado. http://homepages.vvm.com/~curtis/Jarrell/Jarrell.htm

 

[E. Clark]

That was the exact video I was going to post. Breathtaking speed from multivortex to stovepipe to wedge. Studying the damage path you can see the multi vortex damage paths 'within' the wedge just as it hit more populated areas (just before the nursing home - west side).