Monthly Archives: May 2011

Severe

What’s Going Wrong?

This year has had a truly terrible human toll from tornadoes. The current fatality count, approximately 500, is an order of magnitude larger than the average for an entire year. It is to be hoped that this number does not substantially rise, but we do have June, the tropical season (which is expected—and I agree—to be quite active and have a higher than average risk of U. S. hits), and the cool-season secondary severe weather peak. However, this figure is horrible enough even if these periods of higher risk produce absolutely no damaging or fatal tornadoes. Something went very wrong this year, something that has not gone this wrong in almost 60 years, and it is important to determine what it was.

Having followed the stories in a fair amount of depth and from multiple sources, I have developed some suspicions of my own about what some of the problems were. These are problems that either appeared in multiple situations or that appeared in sites where high concentrations of deaths occurred. Other people may form their own opinions, but in whatever analysis of 2011 that takes place (and you can just about guarantee that something of the kind will be done), I hope that the following issues are seriously examined.

1. Safety recommendations for urban residents.
One ugly lesson we have had forced on us this year is that, contrary to long-standing myth about cities being safer than rural areas in tornadoes (perhaps because of the idea that buildings will provide resistance?), a city may well be the worst place one can be in a violent tornado. Even in the age of high-resolution Doppler radar, real-time chaser and spotter reports, live coverage, and 20-minute lead times for warnings, we now know that an EF-5 tornado striking an urban center can result in a triple-digit death toll, as happened in Joplin, MO. It is easy, in retrospect, to understand why a densely packed urban area may be the worst possible place to be. Other than high-rise office buildings, there is no safe place to be. High-rises, according to the EF-scale, will not be demolished even in an EF-5; the maximum expected damage is “permanent structural deformation.” However, directing everyone to the nearest tall office building is a ridiculous “safety” recommendation, needless to say.

What are some other problems with urban areas? Many buildings in the central business district, like fast food restaurants and small businesses, are not constructed to withstand anything like a tornado, and they are simply not safe places to be. Big box retailers will contain very heavy stock that is piled high, providing plenty of potentially deadly missiles. Vehicles are everywhere, and they will become airborne. Designated tornado shelters, which some communities do have, would be useful only if people flocked to these sites well in advance of an actual tornado, because congestion on the roads could result in mass fatalities. Storm cellars would be all but nonexistent, and basements are limited in spatial extent and would be directly beneath the houses, which puts anyone taking shelter therein at risk of exposure to tornadic winds and suction if the house is removed. There is no easy way to get out of danger; traffic congestion will occur if people try to evacuate en masse, putting people in possibly even greater danger than they would have been if they had stayed put. And, of course, cities will have more debris than any other type of community.

We need to seriously consider what kind of safety recommendations can reasonably be given to people who live in town—if any. It is highly uncommon for cities to be struck by EF-4 and EF-5 tornadoes, but it can happen, and the buildings do not provide friction-based wind resistance that would mitigate the effect of violent winds. The situation needs to be looked at to see if any sort of useful specialized safety advice can be given to urbanites.

2. Vulnerability of cell phone networks.
Sometimes when tornado victims are quoted in the news as saying “there was no warning,” what they mean is that they, personally, were not aware of the situation. However, every fatal tornado this year except for one occurred within a tornado watch (link), and that one, an EF-3, occurred within a severe thunderstorm watch. I do not want to sound callous, but there is a responsibility to be weather-aware, which includes awareness of tornado watches and warnings. The outbreaks were all extremely well forecast. Most warnings this year had lead times of 20 minutes or so. In these situations, it is simply inaccurate to say that there was “no warning.” It is passive-aggressively blaming the Weather Service for one’s own failure to be aware.

However, in some cases, there was a legitimate lack of warning, though this is not the failure of the Weather Service. These instances involved the failure of the power grid and the cell phone network, taking down any means by which one might receive weather warnings other than a battery-powered or hand-crank radio. This occurred in some of the small towns that were overrun by the extremely violent EF-5 tornado that traversed northwest Alabama on April 27. I think it also occurred in one of the EF-4 tornadoes of the same day. This is a real problem. Most new phones have the ability to function as handheld PDA, music player, portable gaming device, organizer, Rolodex, e-mail, Twitter, Facebook, and even web browser. With this kind of capability—and none of it dependent on a steady AC/DC power supply—it is easy to understand why people would be reluctant to buy a portable radio. They depend on their phones, and with good reason. However, the cell phone network is clearly vulnerable. If there is significant damage to a tower, down the network goes. This goes for other disasters, including terrorism. The problem needs to be examined to see if these towers can be made more robust. Severe weather outbreaks usually have more than one round, and areas that saw their power and communications knocked out by one (even relatively benign) event can be extremely vulnerable later on.

3. The DTV conversion.
I had a bad feeling about this as soon as the DTV changeover began back in 2009. With the old analog signals, one could have a fuzzy screen—even no visuals at all—and still have audio. With the digital signal, the broadcast becomes choppy, and before long it goes completely black and silent. You have either a near-perfect picture or you have nothing. I have heard more than one anecdote of people in tornado-struck areas who did not lose power until after the tornado hit, but who could not hear the warnings because their TV signal had gone out. I don’t know how many fatalities, if any, were caused by this, but it is a problem that, in my opinion, was severely underrated when the rush to DTV was taking place.

4. Dangerous amateur videography.
There are a lot of videos out there of this year’s tornadoes, and a great many of them were not taken by experienced storm chasers or always-running security cameras. They are also not all taken by people who were a safe distance away from the tornado. One tornado video from Alabama was shot by someone who had a car accident while taking the video! This is a major problem. There is not one thing that can legally be done to stop people from taking video of approaching tornadoes if that is what they want to do, but it is a sad reflection on our society. I don’t blame storm chasers for this. Responsible storm chasers and weather spotters have provided a lot of on-site reports, helping newscasters and people following the situation online know when there is actually a confirmed tornado. Real-time reports of a tornado on the ground helped me decide to evacuate in advance of an EF-5 tornado. Some storm chasers behave highly irresponsibly on the road, and they should be condemned by the rest of the community for it, but overall these people take their hobby very seriously. The videos I speak of are taken by people who just happened to see the tornado and decided it would be a cool idea to get video of it, and the videographers clearly have no knowledge of how far away they should be or where to go if the tornado shifts its path. This particular trend is not the fault of storm chasers; it was produced by social media culture.

5. Lack of shelter from violent tornadoes.
The overwhelming majority of this year’s fatalities have occurred in violent tornadoes, those rated EF-4 and EF-5. This is because these tornadoes will utterly demolish well-built houses, leaving only a pile of debris over a foundation (EF-4) or a bare foundation altogether (EF-5). The Hackleburg, AL EF-5 tornado even buckled the concrete slab foundation of one structure, and the Neshoba County, MS EF-5 (“my” tornado) dug up dirt two feet deep. I think that the odds of survival in these tornadoes are still better than 50-50, but it is easy to see how this kind of situation is incredibly dangerous. The unfortunate fact is that a majority of houses in the South and Midwest do not have basements or storm cellars. My position is that storm cellars are preferable to basements, especially if they have a “fallout shelter” design in which the entrance is not directly above the main room, but is horizontally removed from it. I have read enough accounts of people who took shelter in their basements and were sucked out that (while I agree that basements are clearly preferable to any above-ground shelter) I cannot equate basements and storm cellars. I would also recommend firmly anchored handrails in the main room, in case the door was torn away. The opening sequence of Twister is not myth.

I definitely do not equate above-ground saferooms with underground shelter. These structures are engineered, yes, but they are highly vulnerable on two counts. One, if they are undermined from below, they will roll. Two, the engineering is based on a typical flying missile the size of a 2×4 and a typical flying missile speed of 100 mph. EF-5 tornadoes have wind speeds upwards of 200 mph and have even been clocked as high as 300 mph, though it is a matter of debate whether a large object would travel at these extreme speeds. However, these large objects do travel. In Smithville, MS, the town water tower was dented 120 feet above the ground by a car that became airborne. This is known for a fact by matching paint from the tower and the car. There is video on the Internet of a Canadian F5 tornado in which a whole house is clearly airborne at a great height before it disintegrates.

It’s easy to say, of course, that everyone should have an underground shelter. It is quite another to bring that about. I am opposed on principle to any government mandate to protect people from themselves if there is no risk to other people. This must be a matter of personal responsibility. However, I am in favor of rewarding the decision to install a storm shelter with a tax rebate or credit.  Such credits have been offered in the past, usually to specific regions after particularly high-profile and destructive weather events; I argue that they should be permanent and universal.

These are my suggestions about what should be looked into when the year 2011 becomes part of history, or when people begin to examine what has gone wrong with severe weather preparedness, whichever comes first. Undoubtedly other people will focus on other things. One thing is for certain: We need to know whether this year’s atrocious human toll was in any way preventable, because if it was, it must not be allowed to happen again.

Severe

Running from an EF-5: Part Three

I hope everyone had a good Mother’s Day, or just a good Sunday. This is Part Three of the series about the EF-5 tornado that went through central Mississippi on April 27, 2011. Part One and Part Two are linked.

Days later, after the terrible human toll becomes widely known, the scientific damage surveys come in.  I’d been keeping an eye on them, not really expecting this storm to be high on the priority list because there were fatalities in other areas such as Smithville (it is not known at the time that “my” storm was the same tornado that killed 3 women in Kemper County), but knowing that eventually it would be examined.  One day, the piece of news I have been interested in for personal reasons comes in; the tornado has been rated EF-4 with 180 mph winds.  It began around Philadelphia and lifted outside of Mashulaville.  The Jackson office of the Weather Service helpfully put a Google Earth file on their website that showed the tracks of the tornado and the supercell that spawned it; I download this file and look at it.  The mesocyclone—the strongly rotating column within the thunderstorm—did indeed pass directly over my house.  The tornado itself would have continued straight into downtown Macon if it had stayed on the ground, most likely missing my house, though barely.  This fits with what I heard the day it happened, but now I know just how bad it really could have been for the town.

Like, I suspect, a great many people in the South, I have graphic nightmares about the outbreak for several days.  When some comparatively mild thunderstorms come through a few days later, my nerves treacherously ignore what my meteorology-educated mind is saying, that there is nothing to worry about except lightning.  I dare not suggest that I have post-traumatic stress disorder when I did not actually experience a life-threatening trauma, or when so many who experienced the tornadoes directly undoubtedly do now suffer with this condition, but everything must have degrees, and I am clearly experiencing some degree of being traumatized.  It’s hard not to experience something like this when you leave home with the completely justified expectation that you won’t be coming back except to ruins, even when that turns out not to be the case.  In addition, there is the knowledge of what might have been, with a significant helping of meteorological education and a vivid reading-influenced imagination thrown in for good measure.  There is knowing that the tornado I had run from was every bit as bad as some of the worst beasts of the outbreak—except that it did not last long enough to make a direct hit on a closely populated site.

And then a week after the outbreak, the tornado’s rating is changed to EF-5, the highest on the scale.  This is the kind of tornado that leaves slab foundations swept clean, the kind that reduces every smallish building in its path to rubble, the kind that obliterates small towns.  In the case of this specific tornado, it’s the kind that, by the force of the wind and probably some microscale debris, pulls up blades of grass and digs out sections of the ground two feet deep.  I recall reading a comment by some meteorologist, I have no idea whom, to the effect that he would not believe an F6 tornado could exist (this was in the days when the old Fujita Scale was used) until he saw coffins pulled out of the ground.  Well, there is no such thing as an EF-6, and “F6” was never put into practice because there were no official damage criteria for it, but four more feet and this one would have been capable of that one man’s stated standard.  And yet I think the Hackleburg/rural Alabama EF-5 was still more violent.  The damage survey for that one is responsible for one of my nightmares.

Three women in Kemper County, MS lost their lives in this tornado that I ran from.  They lived in a mobile home.  There were surely others in the South who tried to take shelter in these structures and did not survive.  Trailers are not safe!  Granted, little will stand up to an EF-4 or EF-5, but a trailer won’t even stand up to an EF-2.  And there are a lot more of those than the 4s and 5s.  The Weather Service guideline of leaving a trailer is spot-on.  And even a constructed house isn’t necessarily safe, though the type of tornado that would create uncertainty about survival in these structures is mercifully rare.  However, such tornadoes do happen.  They happened that day in April.  I wish that more people and communities in the South had storm shelters—and underground ones.  Above-ground concrete bunkers may be all well and good, but houses in the Hackleburg and Phil Campbell area had their concrete block foundations destroyed by the EF-5 that went through there.  Also, something capable of digging up dirt two feet deep is quite possibly capable of undermining a slab foundation by the same process and ripping it from the ground by an extreme wind-tunnel effect under the now hollow space.  (That would be beyond anything I have ever read about, but the possibility has been theorized, and this is how it would happen.)  Anyone who can afford it should build a storm cellar—and it bothers me that more people in this region cannot afford it.  There should be a tax credit for it.

I have never left the house before over a tornado warning, or even a suspected tornado.  This was a decision that I made based on the information that was available to me at the time:  my knowledge of the off-the-charts atmospheric parameters that supported violent tornado formation, my experience driving in supercells, the extremely threatening hooked radar signature, the probable debris ball that is usually seen only in intense tornadoes, the path that would have taken it almost directly over my house, and the report from chasers and spotters of a confirmed large tornado with damage and debris.  I decided that the probability of this being a tornado that my house could not stand up to was unacceptably high.  It turned out that the tornado that I fled from was an EF-5, which seemingly justifies the action, and yet I can’t endorse the choice I made as a general public rule.  It happened to be a good decision based on the fact that I had time and I knew what direction to drive, but in general it is a risky decision, and risky decisions should be made only if there is extensive knowledge to support them.  Blind, panicked “I have to get out of here and it doesn’t matter where I go” driving is not something we need.  Anyone who doubts this should take a good look at some of the damage pictures that involve vehicles.  As a matter of fact, extreme vehicular damage was one of the criteria that the Jackson NWS office used to upgrade “my” tornado to EF-5.

Smithville, MS.  Hackleburg, Phil Campbell, Rainsville, Oak Ridge, and so many other small towns in Alabama.  Tuscaloosa and Pleasant Grove, AL.  Ringgold, GA.  And almost, but for the grace of God, Macon, MS.  The nonchalance that at least some people seemingly had comes back to my mind.  I hope it was the exception.  I hope that, after seeing what happened to their neighbors in small towns just like Macon, they are reflecting on their own close call.  Do they know what a close call they had?  Do they realize just how out-of-the-ordinary the tornado that was barreling straight for them truly was?  Do they realize that, if the tornado had not lifted, there would probably be another small town on the dreadful list of “leveled by an EF-5 tornado”?  And yet, there are so many uncertainties.  Would the tornado have maintained that strength if it had stayed on the ground?  Sometimes they don’t.  Or would it possibly have strengthened even more, as the horrific rural Alabama EF-5 apparently did as it tracked north?  No one can know.  But we can make sure that, if something like this should happen again in our lifetimes, we have a plan of action.

Severe

Running from an EF-5: Part Two

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This is Part Two of a series of three about my experience with the EF-5 tornado that went through four counties in Mississippi on April 27, 2011. Part One can be found here, and Part Three, an account of the aftermath, will be forthcoming.

Wednesday, April 27, 2011.

Bzzzzzzz! My cell phone is still in vibrate mode.  I’ve forgotten to turn the ringtone on.  I pull my eyes away from the TV and answer it.  It is my father, who is at work.  “Are you—”

“I know,” I say.  “I’m going to take cover.”

“I’ll call after it passes,” he says.  His voice is clearly nervous.  We hang up.

I take another look at the radar that the weatherman is talking about.  That sure looks like a debris ball, I think, as the menacing supercell enters southwestern Noxubee County.  Then bzzzzz! The phone buzzes again.  This time it is one of my sisters.

“Erin, do you know what’s going on?”  Of course.  I have been following it on the local news, which, unfortunately, is swamped at this point with several simultaneous tornadic supercells, and have just checked the Internet to see if anyone has reported a tornado with this one.  “Well, they are saying in the tornado warning that they’ve got a confirmed tornado—a big one.”

“Does that look like a debris ball on radar to you?”  She says that it does.  “All right,” I say, arriving at a decision instantly, as the crawl-space foundation of this old house flashes before my mind’s eye.  “I’m getting the cat and getting out of here.”  She agrees.

The tornado safety guidelines put out by the National Weather Service do not endorse leaving a house in a vehicle.  I understand why.  In general, a house can be regarded as a comparatively safe place to be in a tornado, whereas a vehicle cannot.  Moreover, it’s possible to get on the road and drive directly into a different tornado or an area of high winds.  When I tell my sister that I’m planning to leave, I know full well that I am going against this advice, and for all these reasons, I don’t recommend that to people in general—certainly not when there is not even a confirmed tornado, and in most cases, not even when there is one.  However, as a meteorology student, I have closely monitored the extreme atmospheric conditions that would be in play for this event.  I am aware that, under these circumstances, tornadoes that form are far more likely than normal to become “violent”—to reach an intensity at which even well-constructed homes are definitely not safe to be in because every wall in them is blown down.  I am aware of what to expect if I choose to drive through the precipitating part of a supercell.  (I was close to the wall cloud of one a week ago, after all!)  I am aware that there is a clear spot north of Noxubee County, and there is nothing that will enter that area in the immediate future.  And, most importantly, I have enough time to get away.

But only just enough.  There is no time to lose.  The storm is moving quickly, and at the angle it’s coming, it will be upon me in 20 minutes.  I grab my laptop, leaving behind even the power cords.  I reflect for a moment on the irony of this; I had recently seen my first AC adapter go out and had to get this one over the Internet.  Well, there is no time to waste by crawling under my desk and unplugging the cord.  I grab my purse.  I shove my protesting cat into the cat carrier.  Carrying only these things, I run into the vehicle, hoping that the lightly falling rain does not penetrate the laptop case, and apparently (so I discover later) leave a rut in the yard in my rush to get out of there.  I head north.

I would not leave my cat at home, but the delay in grabbing up these things has cost me a few more minutes.  Meanwhile, the tornado has not waited.  It’s best not to say what speed I am driving, but no one else heading north is driving any differently.  I wonder how many of them are on the road for the same reason that I am.  The rain slacks off.  I never run into any hail on this trip.

It is between Macon and Brooksville that I start seeing small pieces of branches fall from the sky.  They are not large enough to slam to Earth with violence, so there is something almost graceful in it.  I’ve never seen anything like this before.  These are not being blown about horizontally by winds; they are falling like soft rain from the storm itself.  The movement is vertical.  The branches have been sucked into the mesocyclone, which tilts southwest to northeast; the part of the storm that I am under is nowhere close to the tornado!  Seeing debris brings everything to mind that I have pushed out in my single-minded focus on getting away.  It occurs to me that people somewhere may see debris from my house later on.  Well, I’m safe, and the cat is safe, I think to myself.  There’s nothing more I can do.

Almost mockingly, the sunlight breaks out as I leave Noxubee County.  I hear the buzzing of my phone once more.  It is my father, who has tried to call me several times since my sister called him and told him that I had decided to leave the house.

“You’re fine in that part of Lowndes County,” my father tells me over the phone.  That fits with what I had seen on the radar; I knew that there was a dangerous supercell in Monroe County (the Smithville tornado, it turned out).  I also know that, though nothing tornadic is coming for Starkville and Columbus at the time, I do not want to be stuck in one of these cities if that changed in an hour or so, as it often does during tornado outbreaks.  I also don’t like the idea of pulling off the road indefinitely.  I decide to stop at the house of friends in rural Lowndes County, and there I stay for an hour or so.

I am fully expecting that I will not have a house to go back to, or my house will be damaged beyond repair, or the town will be destroyed.  I’ve read a lot of personal accounts of extreme weather events, and now it seems that I am about to live that awful aftermath.  It is truly amazing how we are able to push thoughts like this out of our minds when we are focused on something critical, such as (possibly) survival itself.  Now that this is not an imminent concern, the ugly realities of a tornadic strike hit me.  I don’t know exactly what will be damaged, or how much, but there is absolutely nothing I can do about it.  All I can do is wait to hear some news.  It is a hideous wait, and yet, I am focusing more on the animal confined in her carrier next to me, and the fact that no one else was at home, than on the home itself.  No one wants to lose a house, but when all is said and done, it’s just a house.

Over the course of my visit, my hosts learn that Macon has not been hit.  The storm apparently passed over with rotation still apparent, but no tornado anymore.  To my astonishment, there was apparently some nonchalance about the whole event in at least some parts of Macon.  Finally I decide to return home, since I still indeed have one.  I get there in time to settle in and watch with amazed horror as live footage of the tornado in Tuscaloosa airs.  Later, I see video of the Noxubee County tornado.  I find out through the TV news and Twitter—Macon, amazingly, has power—that many people in the Southeast are not so fortunate as I have been this afternoon.  My own experience is pushed back to a different corner of my mind as the hideous extent of the destruction and suffering becomes known.  I have not suffered loss.  I focus on those who have.

Severe

Running from an EF-5: Part One

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Note: This is something a little bit different from the usual fare for this blog. Nothing particularly notable is occurring in the South except for the river flooding, and at this point that is a matter of concern for the engineers and hydrologists more than meteorologists. (I could rant about the Corps of Engineers, but that would be better suited for my other blog.) Since this is the case, and since I have felt that I needed to write about my experience on the tornado outbreak of April 27, I’m going to do that. This will be a three-part piece about my experience involving the EF-5 tornado that went through Neshoba, Winston, Kemper, and Noxubee Counties that day. The first part does not even occur on the 27th; it is from a week earlier. I’ve come to the conclusion, though, that it is part of the same story and an important factor in why I chose what I did that dark day.

Wednesday, April 20, 2011. I sit parked on the side of Highway 45, somewhat north of Crawford, in a line of other vehicles whose drivers have made the same decision.  We are all being pelted by hail that I estimate is up to an inch in diameter, mixed in with some rain.  No one dares to drive any farther.  This is, I believe, the third time that hail in this storm has forced me to pull off the road in my drive south to Macon from Starkville that afternoon.  I’ve almost lost count, and that’s not even counting the other storm that produced some hail before I even left Starkville.

I may be in the minority these days in having a cell phone that does not have Internet capability.  Ordinarily that is not a problem for me, but right at this particular moment, I find myself really wishing that I had a radar picture in front of me.  I call my sister and ask her to pull up a radar image on the Internet.  I have some urgent questions for her.

I obviously don’t want the car to be damaged by the hail, but what is currently happening to me is not my primary fear.  See, I have been at Mississippi State University as a graduate student in meteorology, I am well aware that the storm I am under is a supercell thunderstorm, and most likely, I am in what is called the “core” of the storm—the area of the heaviest precipitation.  Supercell thunderstorms are the ones that are most likely to produce tornadoes, and if there is a tornado, the core of the storm is located to the northeast of it.  And the storm is moving northeast.

In this particular situation, I could easily be in far more danger after the hail ends, and that is what I want my sister to tell me about.  I give her my approximate location.  “I think you’re in the hook,” she says uneasily.  (A hook echo on radar is an indication of strong rotation and possibly a tornado.)  My nerves tense at this, but if she can see a hook, it means that there is a slot of low to no precipitation, which I am most definitely not in.  “No, I’m not in the hook,” I say.  “I’m in the core.  I’m getting hammered.  But you are saying there is a hook with this storm?  Is there a tornado warning?”  It turns out that there is, and it is radar- rather than sighting-based.  That’s no surprise, and it certainly doesn’t mean that there isn’t a tornado.  The perils of high-precipitation supercells strike again.  I ask some more questions.  It seems that I am on the north edge of the core, and that based on the motion of the storm, I would be best off staying put until the whole thing is east of me.  The hook should pass south of me if I do that.  I just want to get out of this.  I’m not opposed at all to storm chasing, but it’s really not something I’m inclined to do without another person in the car or live radar available.

Once I am on the road again, I get a glimpse of the wall cloud off to my east with the aid of the nearly constant cloud-top positive lightning flashes that the storm would put out as it intensified.  I recall from my thesis reading that intensifying supercells often do produce a great deal of positive lightning.  This particular supercell would go on to produce larger hail and threaten Columbus.  I take several hours to come down from the adrenaline rush.  One week later, I would be very glad I had this experience.

Part Two of this will be about what happened to me personally on April 27. Part Three will be the aftermath of that event.