Multi-day outbreak of May 25-31

[Ntxw]

The EF scale is used to obtain WIND estimates

So why wouldn't you use actual data to obtain what you are SUPPOSED to obtain?

Perhaps I didn't make my posts clear or was misunderstood. USE the actual data, I trust it I am by no means against it in fact all for it! But the EF scale is a researched system that measures damage and was not intended for direct input of wind speed data, wind speed estimates was a side outcome of this research. It's an outdated system they need to incorporate these new wind measurements yes, but there is no guideline created in the EF scale to tell us what is acceptable wind speed data and what is not. I have no problem whatsoever using the measurements for this tornado or any tornado, but that is not what the EF scale was created to incorporate. It needs to change. For them to give the rating EF5 without seeing the damage (unless they did and we do not know) as the scale is for, it's not setting a good example.

From the SPC

"*** IMPORTANT NOTE ABOUT ENHANCED F-SCALE WINDS: The Enhanced F-scale still is a set of wind estimates (not measurements) based on damage. Its uses three-second gusts estimated at the point of damage based on a judgment of 8 levels of damage to the 28 indicators listed below. These estimates vary with height and exposure. Important: The 3 second gust is not the same wind as in standard surface observations. Standard measurements are taken by weather stations in open exposures, using a directly measured, "one minute mile" speed. "

http://www.spc.noaa.gov/efscale/

[EF-5bigj]

I think the EF rating will change to include measured wind speeds. This one tornado had caused a lot of good discussion on everything from safety to chasing to the science. R.I.P Twistex

[Cyclenall]

I'm not surprised it was upgraded to an EF5 because it was painfully obvious based on radar velocity scans this thing was in its own league, but almost everything else from the report was unthinkable, even more crazy than first thought (it went from being 1 mile wide to 2.6 miles wide in less than 1 minute! Something so mind-blogging that it revolutionizes what tornadoes can do). No wonder chasers died in this, it was the total worst case scenario for chasers, I actually cannot think of another factor that could have made it even more dangerous for them (other than chasing this at night or something), it was the max for danger. That's all there is to it.

I'm extremely happy that there was so much data collected on this tornado from all sorts of equipment, certainly one of the best tornadoes ever to use it on. I don't think I could take this being an EF3 officially, just no. There should be at least signs of the ground being ripped up underneath the EF5 spot but rural twisters this strong seem different. I don't think there has ever been a time when I wanted to sit down with Dr.Howard Bluestein and talk about his findings and data more than I do right now after this latest monster tornado.

296 mph at roughly 500 ft (150m) would translate to what? 250 mph at the surface?

Not sure how it is over land, but over water, that would be about 250-265 mph using the approximate 85-90% rule from tropical systems.

Why are we assuming there is even a conversion factor at all? This isn't a TC, totally different. I recall reading the difference when speaking 100 m roughly was very slight (in tornadoes) but I'm not sure.

I don't even want to think about it, but it was pretty well covered in "It Could Happen Tomorrow" on the weather channel, the only difference was that was Dallas and this is OKC, but not much difference in terms of unholy damage if it was 25 miles farther east so this was probably a blessing it cycled before heading into the OKC metro area

It cycled before putting down more tornadoes into the Metro, which to me sounds like bad timing not good. We also can't exaggerate too much to say it could have held that historic strength for that whole duration either, over 20 minutes to reach downtown. It has to be perfect timing basically like Joplin and Moore. It also raises the other question of why these powerful tornadoes even cycle at all, if the environment is insanely perfect, what's the problem? I don't remember tornadoes on April 27, 2011 doing this cycle business. I put this question in my thread of tornado and severe questions in the Ask A Question sub-forum.

[EF-5bigj]

I think that it's great they got so much data from this historic tornado. It's tragic that it took the lives of the Twistex team though but I imagine he would have been all over this data as well. It's kind of ironic that a tornado that was well studied and had lots of information gathered about it took them out. I'm not trying to be insenstive about their deaths though as they are tragic

[brunota2003]

296 mph at roughly 500 ft (150m) would translate to what? 250 mph at the surface?

Not sure how it is over land, but over water, that would be about 250-265 mph using the approximate 85-90% rule from tropical systems.

Why are we assuming there is even a conversion factor at all? This isn't a TC, totally different. I recall reading the difference when speaking 100 m roughly was very slight (in tornadoes) but I'm not sure.

My comments about that are, I know friction is greater over land than over the ocean, and I truly am curious what it would translate to on the surface. Obviously this isn't a TC, but as far as any potential conversion goes, that is what I have the most experience with, and what I tend to "fall back" on. I was just wondering if anyone knew the answer to the question, is all.

[EF-5bigj]

I still find it amazing that it was so big yet so powerful. 296 mph winds and that wide

[HurricaneBill]

What a two-faced tornado season this has been. First it was practically non-existent, then along came May and two historical tornadoes.

[EF-5bigj]

I know it was like there was a drought then we have 2 EF-5's 11 days apart. Which is historical to but the El Reno,OK 2013 EF-5 seems to have set more then a few records some amazing like its width and wind speeds to the tragic deaths of veteran storm chasers.

[Cyclenall]

What a two-faced tornado season this has been. First it was practically non-existent, then along came May and two historical tornadoes.

That two-faced concept you speak of is Equilibrium which exists in all sides of weather. I was confident this tornado season wasn't going to go quietly in the wind, during the midst of almost nothing in early May. If its not going to be a scorching Spring, something else had to take its "spot" in the interesting weather category.

My reaction to the news of the El Reno EF5 tornado being what we now know it to be:

[EF-5bigj]

Quiet spring for sure then we have to historic EF-5's. The El Reno 2013 EF-5 will studied for a long time to come. Oklahoma this year has just not gotten a break. I mean not 1 EF-5 but 2 only days apart is insane.

[Cyclenall]

OLDER RESPONSES FROM MAY 31:

Low level shear/wind profiles aren't that great over Oklahoma and adjacent areas today. Models aren't bullish with storms firing there either. If I had to pick a region it would be Ohio valley and mid Miss to continue the gradual eastward shift since Monday.

Sweeping cold front will be coming through southern plains later tonight and tomorrow which could bring an additional linear mode of storms.

This was the morning of the El Reno EF5. Not to rag on you or anything, but pretty much everything in this post was the opposite of the outcome. I don't remember reading a synopsis from you about the aftermath or what went differently because I think the shear was very high otherwise it would have been nearly impossible to get an EF5 and one of the strongest tornadoes in history. I remember the short-term models actually going crazy (supercell formation) over C OK that day as well. Ohio valley and mid MS had nothing notable.

One PDS watch this year, on April 18, which busted. I'd expect a PDS watch to be issued this afternoon in that core area though.

I forgot to mention this, but that PDS on April 18 was the largest PDS bust in recent memory; most mets were scratching their heads when it was first issued. I think there wasn't even a severe thunderstorm in that PDS box.

Those in OKC should certainly stay off the roads if at all possible between 4 and 7 pm and have access to an underground shelter if necessary. They could either try to leave from work early (if safe at home) or stay longer (if safer at work). Did they dismiss schools early or cancel schools today?

Reading this, in hindsight this was somewhat ironic that this advice was not only not heeded at all that day, but the worst road conditions in chasing history occurred. What a premonition.

[That goes back to what I've been trying to say abut these threads. This is Spring; really nothing unusual or extreme. Yeah, Moore got hit bad for the second time, and we're in our second streak of 4 or more Moderate Risk days, but all-in-all, it's been a fairly unremarkable season.

In fact, it's been more remarkable for what hasn't happened; namely the record flooding that was expected from all the late snowfalls.

Is it remarkable now? To me, its more amazing than 2012, 2010, 2009, 2006, etc. Its not the numbers I care about, its what happens from a unique perspective. The last part about the flooding is happening now, just a few days off on that one.

[Ntxw]

I appreciate the criticism and admit that was a tough day model watching for me. I really did not see that favorable of a low level wind shear environment. Looking back the tornado occured in a very localized environment that had ridiculous cape and instability which fueled this monster. When trying to see something that small an area its hard to call for a record tornado to occur. In all there was an Ef3 near St Louis from a linear mode tornado as well as others in Illinois and Missouri so the Ms/Ohio valley basins were effected on a larger scale in terms of coverage than Oklahoma, but of course OKC metro had the biggest one.

[Cyclenall]

OLDER RESPONSES

I don't want to sound insensitive, but Oklahoma City was fortunate yesterday. There was potential for a total catastrophe yesterday that would have been referenced for decades. A strong or violent tornado tracking across I-35 yesterday would have caused a death toll beyond belief.

Its not insensitive but its not true either, OKC was not fortunate during this event. The city would have been fortunate for nothing to happen, not tornado touchdowns in the metro, widespread straight-line wind damage, and historic flooding causing sinkholes and killing people. Extremely likely it was a billion dollar disaster.

We have to remember, too, that even in violent tornadoes, the area affected by EF4-EF5 winds are rather small. The majority of the area sees less, easily survivable damage.

For the first time this year, I have been reading this fact or tidbit about violent tornadoes a few times. I actually think it might only apply to certain wedge tornadoes, the circulation of a tornado is not as simple as a hurricane or TC...there can be vortices dancing anywhere within it so its not straight-forward to say the middle has the worst. There is a correlation with that but because debris is being wiped at such a speed towards other regions (of the twister), it may negate the difference sometimes.

:uarrow: I appreciate the criticism and admit that was a tough day model watching for me. I really did not see that favorable of a low level wind shear environment. Looking back the tornado occured in a very localized environment that had ridiculous cape and instability which fueled this monster. When trying to see something that small an area its hard to call for a record tornado to occur. In all there was an Ef3 near St Louis from a linear mode tornado as well as others in Illinois and Missouri so the Ms/Ohio valley basins were effected on a larger scale in terms of coverage than Oklahoma, but of course OKC metro had the biggest one.

I see. For me I tend to look at the worst area for highest potential and go with that for the overall potential so even localized events mean something in the big picture. If the high-res short-term models show supercells juxtaposed over it, I have an easier time calling for something huge to happen in those scenarios. So you consider Missouri to be in OH valley?

[Ntxw]

Mid Miss for me is middle Missisppi valley which includes Missouri not to be mistaken by the state which I consider the lower Miss or mid south, the two rivers meet in the Missouri boothill

Also I don't like using just instability in seeing if severe weather or tornadoes will happen. There have been far more times when it busts thanks to the cap that happens in southern plains (this cap though is what makes these storms explode if it breaks). If you see more coverage in models the better the chances of breaking vs a few cells in this region.

[EF-5bigj]

http://youtu.be/KX8o2loAMhY. Jeff P. video of the 2013 El Reno EF-5 tornado.

[Alyono]

seeing some at SPC want to downgrade this to an EF3

I take it they want to say a tornado has winds no higher than 165 mph when there are recorded winds near 300 #questionablescience

[EF-5bigj]

Yeah I don't know the other El Reno was also upgraded due to volicity readings. Well I think like the Tuscaloosa tornado the El Reno 2013 EF-5 will be controversial ratings wise. But it's surprising there is disagreement on its rating.

[Alyono]

Yeah I don't know the other El Reno was also upgraded due to volicity readings. Well I think like the Tuscaloosa tornado the El Reno 2013 EF-5 will be controversial ratings wise. But it's surprising there is disagreement on its rating.

My suspicion, dinosaurs who are unwilling to adapt with the times are opposing the EF5 rating

[Ntxw]

The issue is not with the wind readings, SPC knows this thing will do EF5 damage over populated areas. The problem lies in the Enhanced Fujita scale not the tornado. It's an apples to oranges situation, as I've tried noting before. When the NWS records data for weather (temps, precip, etc) it follows a strict guideline, if it doesn't follow those guidelines the data is often thrown out and rendered not properly collected. There is no guideline in the EF scale about wind measurements, it just doesn't exist. Best solution here is for the SPC to change their stance and include proper guidelines for wind measurements, allow them into the EF scale then retroactively upgrade this tornado and all the others that have acceptable measurements via the guidelines.

Yeah I don't know the other El Reno was also upgraded due to volicity readings. Well I think like the Tuscaloosa tornado the El Reno 2013 EF-5 will be controversial ratings wise. But it's surprising there is disagreement on its rating.

The 2011 El Reno tornado hit homes and other structures that showed evidence of EF5 damage with cars bent around trees, so it was much easier to give the ratings based on damage.

[EF-5bigj]

Clearly the EF scale will have to be changed due to wind speeds being recorded now. I think this tornado is causing a good discussion about the EF ratings system though. Despite all the tragedy that came from this event this tornado has caused a lot of discussion from safety to metrology. Although a tornado expanding to 2.6 miles wide in less then a minute still amazes me.