With the 2011 Super Outbreak, meteorologists are starting to work out an approximate historical return period for these large-magnitude events.  Before the 1974 event, the last comparable event occurred in 1936, with an outbreak popularly known as the Tupelo-Gainesville outbreak for the violent tornadoes that occurred in Mississippi and Georgia.  It seems that these huge events occur approximately every 35-40 years.  Obviously, a comparable event could occur next spring, but statistically, it seems that they are a 35- to 40-year event.  And, given that the 1974 Super Outbreak and 2011 Super Outbreak saw comparable death tolls, I think we can also estimate what the human toll for such an event will unfortunately be as long as the affected communities have unsuitable safety options for EF-4 and EF-5 tornadoes.

The Joplin tornado is a different beast.  We do not have a comparable modern event.  Individual tornadoes in 1953 killed over 100 people in Waco, TX and Flint, MI, but that year was something of a catalyst of public outrage, for a third tornado in Worcester, MA killed 94 people.  Public sentiment that year was essentially, “DO something so that this never happens again!”  And for 57 years, no single tornado in the U.S. did kill over 100 people.  Then… it happened again.

Was the Joplin event a worst-case scenario?  Is this the deadliest (give or take) that a single tornado can actually be now?

I think the answer to the first question is a guarded “yes,” at least for the specific case of a tornado striking a city.  The tornado was about as strong as they come; its winds were estimated to be up to 250 mph.  They can get more intense than that, but it doesn’t make a lot of difference in terms of structural damage.  The tornado rapidly intensified precisely as it entered the heavily populated regions of Joplin, and it passed right through residential and commercial shopping areas—the worst areas it could strike.  Examination of the track shows that there was also a pretty large corridor of EF-4 and EF-5 tornado damage, which would be expected for a wedge tornado.  Sometimes the area of violent damage is comparatively small, but this was not the case with this tornado.  Storm cellars were rare in this area, making survival above ground mostly a matter of good luck.  The tornado was also rain-wrapped for much of its existence.  In terms of the storm’s power and the location of impact, you can’t get much worse than this.  However, I should note that it occurred on a Sunday.  Some have argued that if it had happened at the same time of day on a work day, it could have been worse.  We don’t know for sure, and let’s hope we don’t find out.  I tend to think it probably would not have been much worse, given that residential areas (not a likely area for commuters to be stranded) and the shopping district (which probably would get more foot traffic on weekends than work-week afternoons) were such a large part of the damage zone.  In my opinion, the Joplin tornado was essentially a worst-case scenario for a tornado striking an urban area.  A comparable tornado striking an urban area probably would have a comparable human toll.

Unfortunately, the second question—is the death toll of ~160 the highest we could see for a single tornado in the modern era—has a different answer.  There are two ways that a single tornado could kill a lot more people than that.

One is the possibility of a weak, poorly-built or dilapidated high rise building taking a direct hit from a violent tornado and collapsing with a lot of people inside it.  Generally, these buildings are not supposed to collapse even in EF-5 events.  Images of collapsed high rises on hurricane landfall sites are misleading; these buildings mostly had shallow foundations and were undermined by the storm surge.  They were not blown over by wind alone, and storm surge is obviously not a factor for tornadoes.  The St. John’s Hospital building in Joplin took a direct hit from the tornado when it was at EF-4 intensity and it did not collapse.  However, a poorly-constructed or dilapidated one could.  (As an aside, one does have to wonder about the possibility of a tornado tearing up ground several feet deep, as happened in the EF-5 tornado on April 27 in central Mississippi. This could definitely undermine a slab foundation on a house, resulting in the foundation being ripped from the ground—the supposed hypothetical “F6 intensity” signature that one heard bandied about prior to the adoption of the Enhanced Fujita Scale.  However, high-rise buildings have much deeper foundations than residential homes.)

The other possibility is that of a violent tornado striking a crowded spectator event, such as a sports game, a fairground, a speedway, etc.  This possibility has been discussed at length by meteorologists such as Dr. Roger Edwards of the Storm Prediction Center.  It’s almost happened before, in fact; in 2008 an EF-2 tornado in Atlanta, GA struck the Georgia Dome while a basketball game (involving my college team) was going on.  It had gone into overtime, so people were not milling around outside.  Still, there are videos from that event of pieces of the roof collapsing and falling to the floor while the spectators were left to fend for themselves in the stands.  A stronger tornado could very easily have taken that roof off.

So yes, although the Joplin tornado was very likely a worst-case event for a tornado strike on a city, thereby representing an approximate limit on fatalities for that type of disaster, the potential exists for individual tornadoes to kill far more people than that in a different sort of disaster.  Let us hope that we can deal with the infrastructure and the safety considerations of large venues so that these greater disasters do not occur, either in 2012 or years to come.

The bulk of the research involved surveys of people from the areas that were impacted by tornadoes in 2011.  The surveys contained questions about NOAA watches and warnings (whether people received them, how they received them, whether they were understood) and people’s responses to these messages.

Here are some points I took away from the social science presentations:

• An overwhelming majority of people in impacted areas did receive warnings.
• A very small minority of them immediately went to shelter after receiving a warning from the first source.
• A rather large plurality sought out additional information from TV, the Internet, or personal confirmation to determine if the tornado actually existed and would potentially affect them.  This was more likely in people with higher levels of education and in people who knew more about the weather.  (I would like to note here that this is exactly what I did when the east-central MS EF-5 tornado of April 27 was heading my way.  I did not immediately barricade myself under the stairs when I heard the warning.  I looked at radar to identify a probable debris ball signature and plotted its projected path to go right over my house.  I then grabbed my cat and got out of town.  The tornado lifted, but if it had stayed on the ground, I could have been killed as a result of following the canned advice rather than reasoning out the best course of action for myself!)
• A minority of people chose to completely ignore a warning.
• When asked how likely they, personally, thought it was that their area (of what radius?  I don’t recall if it was stated) would be significantly impacted as a result of bad weather mentioned in a warning, the most common answer was less than a 25% chance.  The social scientists said that they wanted people to guess a nearly 100% chance, but in fact, the scientifically and statistically correct answer was less than 5%.  Interestingly, this arguably refutes the “optimism bias” argument in that people did give a more pessimistic judgment of their risk level than was really the case, just not pessimistic enough to suit the social scientists.

The social scientists seemed to be dismayed by the fact that people were less likely to immediately dive for cover the more educated and weather-savvy that they were.  Needless to say, this is an odd message to deliver to a room full of meteorologists (many of whom actively seek out bad weather in their vehicles).  What is the point here?  “Ignorance is strength,” to quote from Orwell? Let alone that people can’t exactly become less weather-savvy, less educated, or more paranoid about the personal impact from a storm if they already know better.  This is an example of trying to close the barn door after the animals have escaped.  These things are what people do, and with the proliferation of web phones with more and more features that allow people to have access to information virtually anywhere, these behaviors are only going to become more common.  This means that they are the behaviors that must be worked with and planned for.  Trying to force people into a state of unnecessary and statistically unwarranted fear is not going to work.  Nor is it a good idea to try to bully people into not seeking out information and using cognitive reasoning.  I’m no social scientist, but I can tell you that if this is attempted, the most likely reaction is a rebellious contempt for “the government” for “trying to make us not question, not think for ourselves, and do as we’re told.”  I would be just about willing to guarantee it.  It could backfire badly.  People ultimately have to be responsible for their own decisions.

Furthermore, there was absolutely no evidence given that people who sought out more information first were more likely to be injured or die in an event, and obviously the survey methodology required interviewing people who did not die.  Knowledge about what the people who died did must come from people who were with them and survived.  However, I never even saw that there was a distinction made between the group of people who were in the path of the tornado and were uninjured or had only minor injuries, and those who were severely hurt or killed.  It would have been useful to find out if the people who were severely harmed did anything differently from those who were more or less okay.  Given that at least one of the surveys was conducted via e-mail shortly after the event in question (the Tuscaloosa tornado), I would expect that there would be very few people who were severely injured who even participated in it, because they would have been in the hospital.  In effect, the social scientists gathered statistics about a control group and presented it as though it represented the experimental group.  In this situation, the statistics about behavior patterns following a warning mean nothing in themselves.  There is nothing (survival/non-survival, minor/major injury) to correlate them to.  Implying that these behaviors caused the death toll to explode is unsupported speculation.  The one survey I saw that definitely interviewed people who had lost loved ones or who were severely injured was conducted in Smithville, MS, and these authors did not make any wild inferences about how seeking out additional information had led to the deaths.  There is simply no data support for it.  The only situation where it might make a difference is when the lead time is basically zero and every second counts, which was not the case in the April 27 tornadoes or the Joplin tornado.  (I had a lead time of about 25 minutes, which was enough for me to get my cat and laptop and go 18 miles away.)

There was one data omission that is, in my perspective, more important than any behavioral survey.  One table that I did not see in any of the social science presentation was this one:

(Credit to the Storm Prediction Center: http://www.spc.noaa.gov/climo/torn/fataltorn.html)

That is, 95% of all tornadic deaths this year occurred in EF-3 or higher tornadoes, which will destroy most or all walls in a house.  EF-5 tornadoes can even expose the basement and descend into it (it is a myth that the funnel would magically stop at the ground level if an open hole existed for it to twist into), sucking people to their deaths.  And it gets even more significant when you dig deeper into the data.  A look at the list at the top of that page shows that only 4 of the deaths from EF-2 or weaker tornadoes occurred in permanent houses.  I don’t know exactly what happened there, but it could have been extremely bad luck such as a tree falling on the house, a piece of heavy furniture, or a piece of timber causing injury.  It could have been a weak structure.  The point is, this is very rare.  The rest of the deaths in EF-2 and weaker tornadoes were in trailers, vehicles, outdoors (all highly dangerous places to be in a tornado) or were unknown.

I respect the research into this year’s terrible tornado casualty count.  It is important to determine exactly why this occurred, and one question that did need to be answered was whether it happened because of bad decisions.  This is the question that the social scientists have attempted to answer.  I simply disagree very strongly with their apparent conclusions, as I think they are unwarranted by the questionable research methodologies, and are little more than speculation.  My contention is that the catastrophic death toll is directly attributable to major, violent tornadoes, the kind that obliterate entire homes, happening to occur in a lot of populated areas this year.  In short, it was a statistical outlier year.  This classification does not address the underlying structural problem of the Southeast, which is that effective storm shelter is not commonly available for the most violent events, but that’s not an easy problem to resolve.  Unfortunately, in my opinion, it is this hard problem, rather than comparatively easy ones regarding bad decisions, that must be answered if this type of death toll is to be prevented from ever happening again.

Steering in the short term is straightforward.  Emily has been generally on the left side of the forecast track for most of the day, and it is now expected to make landfall in the Dominican Republic as a tropical storm.  Weaker systems generally weather the mountains better than stronger ones, provided that they do not linger in the area; therefore dissipation of the system seems comparatively unlikely.

Models conclude that trough will miss Emily

The models have largely converged on a scenario in which the trough that is to weaken the Bermuda High will be gone before it can force the full recurvature of Emily.  The ridge is expected to build back in, and the GFS shows the hurricane being trapped off the coast of Florida, unable to move ashore because of another ridge, stalling until a shortwave trough lifts it away.  The GFDL and HWRF models, which take their input from the GFS, both show a very close approach to the east coast of Florida, with the HWRF showing near-hurricane-force winds onshore.  The NOGAPS shows this same scenario without the stall.  In this scenario, a landfall on the Outer Banks of North Carolina occurs, followed by a pull up the Atlantic seaboard (offshore) and out to sea.

The Canadian model shows a very weak system, probably no more than a mild tropical storm, making landfall on the east coast of Florida and then being merged into the shortwave.  I should observe that the Canadian model now shows the first low strengthening to 988 mb at sea and reducing the Bermuda High to its winter stage (the Azores High), which does not seem remotely reasonable to me for an August system.  I am not putting a lot of faith in this aspect of the Canadian solution.

The European model also shows a “screwy” solution, amplifying the shortwave trough to 992 mb at sea, while completely dissipating Emily over Hispaniola.  Although unlikely in my opinion, dissipation of the tropical storm is certainly possible, as yesterday’s blog entry said, but I am having great difficulty believing that either of the baroclinic low pressure systems involved in this will reach 990 mb levels.  The first trough is currently located in New England producing a severe weather risk, and it is analyzed at 1002 mb.

Bottom line, I am giving a highly skeptical eye to anything that destroys the Bermuda High at the beginning of August and amplifies low pressure cores to winter levels, especially when they have not been doing this consistently.  Any land-free recurvature of Emily depends entirely on such “bombs,” and the approach to the East Coast will be so close that a weaker trough or shortwave will make all the difference in the world in what wind speeds are felt onshore and whether landfall occurs.

Gulf Coast threat decreases… for now

As should be apparent, the threat to the Gulf Coast states has decreased over the course of the day (with a caveat).  The current thinking is that the trough will lift Emily northward enough to miss an entrance into the Gulf of Mexico.  However, this could change if the storm stays south and west enough, or the trough is weaker than expected at sea.

Because of its delay in getting organized, Emily is a threat to the United States.  I am going to blog regularly about this system as long as that remains the case.

What’s the synoptic setup?

Emily is going to move mostly west, slightly WNW, along the southern end of the Bermuda High.  Its strength will depend primarily on possible land interaction during this time.  The National Hurricane Center forecasts an impact on the island of Hispaniola, which would weaken the system.  How much remains to be seen; many a major hurricane has been reduced to a tropical storm by this island, but some systems that are much weaker have survived passage.  It is terribly difficult to forecast how much effect the mountains will have on any particular storm.  A lot depends on how well-organized the system is when it reaches the island (I do not mean its intensity; intensity and cyclonic organization are not the same thing), how long it stays there, and whether there are any additional destructive factors such as dry air intrusion and wind shear that are hitting the storm at the same time.  It is arguable that there’s not a lot of point in making a forecast for Emily after its interaction with Hispaniola at all, because what happens to it after that will be heavily influenced by its strength at that point.  I’ll discuss the various possibilities, however.

The high is going to be weakened on its left flank by a trough coming off the Atlantic coast in a couple of days.  This should pull the storm to the north.  How much depends on how weak Emily is and how strong the trough has managed to become.  The stronger Emily is, the more northward it is expected to move, all things being equal with respect to the trough.  I think that the trough will be the most important player here, though, and should be watched at least as closely as the tropical system.  It is very uncommon to have a strong trough coming off the East Coast at the beginning of August, and there has been a pattern this year of the GFS (the U.S.’s long-range weather forecast model) overdoing the strength of lows in the days before they arrive.  I am not inclined to buy into a strong trough unless I see it materialize, but it’s always best not to count anything out, either.

Emily is probably too far south and west to have a land-free recurvature (“fish storm”) path.  It’s not impossible, but it is unlikely.  It simply took too long to develop for that to be the most likely track.

What’s the model spread?

Models generally have clustered around the state of Florida as of Monday evening, with the NOGAPS (U.S. Navy model) farthest west and the GFDL farthest east.  The NOGAPS is showing an implied strike on the Florida panhandle (it has Emily stalling in the Gulf and not making final landfall within a 7-day period), and the GFDL shows a “fish storm” recurvature.  It is important to observe that this trend for the GFDL is relatively new; until the past 24 hours or so, that model was showing a strike on the East Coast of Florida and the HWRF model was showing a recurvature.  Now that has reversed itself.  In the meantime, the NOGAPS has been consistent in its Gulf track.  Consistency alone is not a reason to support a model’s output, but it is generally indicative of a model’s having a better grip on the environment than one that is prone to the “windshield wiper effect.”

Is the Gulf Coast at risk?

Short answer:  yes, but it’s not set in stone.  As of now, I still would say that the Florida peninsula is most likely to get hit, but the Gulf is a definite possibility, especially if Emily is weakened by interaction with land and/or the trough is weak.

Several forecasts indicate that the storm will remain weak for long enough to stay south and get into the Gulf of Mexico before making the recurvature.  This is not a fluke, or a one-off from some model; it has been a solution for the NOGAPS, Canadian, and UK several times over the past two days.  Furthermore, models such as the HWRF have been hinting at a Florida East Coast strike at a perpendicular angle, indicating a strengthening ridge that would force Emily westward again.  While these models do not go out far enough yet to indicate what would become of Emily after the Florida strike, entry into the Gulf (in a weakened state) is certainly possible in this scenario.

It is important to note that, even though the current state of the system is less organized than yesterday and the National Hurricane Center has lowered its percentage of becoming a tropical cyclone in the next 48 hours (which I would completely agree with), 90L has gained additional model support for its long-term development prospects.  The cyclone-specific HWRF model was on board with 90L yesterday, taking it just south of Cuba and bringing it to 60 mph by the time it passes by.  Today the HWRF keeps the system even farther south, intensifies 90L to a Category 1 hurricane, and sends it into the Yucatan.  Additionally, the GFDL cyclone model, which was not doing anything at all with 90L yesterday, is today showing a Category 2 hurricane striking the Yucatan.  I think that is overdoing it, personally, but this system is showing indications of going into the Gulf of Mexico and intensifying then.

In recent hours, it has become possible that 90L is experiencing a center reformation.  The center has been located in the part of the system that is now south of Puerto Rico.  However, increased convection just south of Hispaniola (Fig. 1) is changing the polarity of the system, as is evident in upper-level divergence charts (Fig. 2).  This convection is likely associated with the mountains and therefore does not indicate improvement in the tropical structure of 90L.  However, if the center reforms to the northwest, this will throw a great deal of uncertainty into even the survival of 90L, as it will come much closer to the destructive mountains of Hispaniola and Cuba.  If the reformation does not occur, we are looking at a track like that of the GFDL and HWRF.  For my part, I am finding it hard to get on board with a center reformation over a more destructive environment that will make it hard for existing centers to stay together, let alone new ones to form, but time will tell.

One more important point to note for the GFDL model run is the strong ridge that would, in that scenario, serve to block 90L from moving north after it enters the Gulf.  The blocking ridge does not extend that far west in the HWRF run, making a Central Gulf landfall possible.

In summary:  90L is in a state of transition at present, and the outcome of a number of possibilities will determine its fate.  If the center reforms to the northwest, the GFDL and HWRF tracks should not be considered because they assume the present center.  The result of a reformation would be more land interaction, which means a weak system, delays in development, and the possibility of complete dissipation.  If the center does not reform, the GFDL and HWRF scenarios are in play, opening the doors for a significantly stronger system (and it should be noted that those models only go out to 126 hours, and have the system as an organized hurricane or near-hurricane in the middle of 90°F waters and low shear).  The ultimate landfalling location of 90L will then depend on the strength and extent of the ridge.

Figure 1: Rainbow-enhanced infrared image of 90L, Saturday evening.

Figure 2: Upper-level divergence over 90L.

The system has been steadily increasing its convection over the course of the day, and with this increase has come an improvement in its cyclonic structure.  Cyclonic curvature is evident on satellite (Fig. 1), and upper-level divergence (Fig. 2) indicates good ventilation for the system.  Lower-level convergence (not shown) is not so impressive, indicating that the system needs to form a strong low-level circulation to be considered a tropical cyclone.  This is usually the last step that developing tropical cyclones take.

90L is in a simple steering regime, being located south of the Bermuda High.  In about 3 days, a trough associated with a cyclone is expected to be located off the East Coast of the U.S., eroding the high somewhat.  It was previously assumed that this temporary weakening of the ridge would result in 90L being drawn north for a recurvature.  However, recently, it has become likely that the trough will be weaker than previously believed.  90L is also expected to take longer to develop owing to shear and likely land interaction.  The net result will be a stronger ridge and a weaker tropical system, and the consensus is that 90L will be forced into the Gulf of Mexico (Fig. 3).

90L will have to pass through an area of 20-knot wind shear (Fig. 3, Fig. 4), which is moderate, but will inhibit strengthening for as long as the system is located under that wind regime.  The GFS model does not indicate a sharp spike in wind shear over the course of 90L’s trek toward the Gulf of Mexico.

Unless the expected path drastically changes, 90L should enter the Gulf in about four or five days.  Models are unreliable for storms like this in the long range, and it should be noted that some of the models, like the GFS, are not particularly impressed with this system in the first place.  However, the cyclone-specific model HWRF does develop 90L into a 60 mph tropical storm, keeping it south of Cuba by the end of its run (126 hours out).  For my part, I am disinclined to accept a forecast of zero land interaction at this point.  However, the salient point is that any interaction with Cuba or Hispaniola will have a profoundly negative effect on 90L’s short-term intensity even if it becomes a tropical storm before reaching those areas, and avoiding those landmasses will result in a stronger cyclone that has not been delayed by a reorganization after being disrupted.

My gut forecast for a week or more out (in other words, break out the salt!) is that this system will become a tropical cyclone of moderate intensity (I’ll say Category 1, max, because of mild levels of shear in the Gulf even though the temperatures are well over 90 degrees in many areas) and that it will make landfall somewhere west of Pensacola.  I will have updates about this system if it continues to be a concern.

Figure 1: Shortwave infrared satellite of 90L, late Friday night

Figure 2: Upper-level divergence for 90L, late Friday night

Figure 3: Google Earth overlay of model tracks and shear for 90L, late Friday night

Figure 4: Wind shear tendency, late Friday night

I don’t see a lot of point in making a specific numerical forecast for this year’s hurricane season. Suffice it to say that my best guesses that I formed in winter are unchanged, and that I expect an active season with a higher-than-average chance of American strikes, unlike last season. I am not expecting a transition to El Niño, which would tamp down activity in the Atlantic, but I am not entirely sold on the expectation that the ENSO state will remain neutral throughout the season.  I think there are close to even odds that it will begin to return to La Niña conditions again by autumn, albeit milder than those of last winter.  However, either pattern will promote tropical activity.

Did I mention checking tropics-related web bookmarks once more?  Well, it turns out that the Atlantic basin is following the “official” calendar right on schedule, so I have reason to look at the tropics regularly already.  There is a disturbance in the Caribbean Sea that is the first really interesting possibility for tropical development.

Here is an image of how this disturbance looked at 11:00 PM Thursday night:

For reference, here is a true visible satellite image of the same disturbance a few hours earlier, which shows the mid- to low-level circulation of this system better:

There are two “blobs” in the Caribbean, but the first image makes it clear that the one to watch is the one closer to Central America. That is the one that, according to loops of visible satellite images, has visible rotation occurring, and it is analyzed as a low pressure center in official maps:

The area of convection to its east is associated with a tropical wave that is expected to merge with the low, adding energy and moisture to the brew.

This system is interesting for so early in the season because it has some atmospheric variables in its favor despite the calendar. The low has been developing low-level convergence (winds drawing together) and upper-level divergence, both of which are conducive for tropical cyclogenesis, though these areas of convergence and divergence need to become better aligned with each other:

As the images indicate, the area of convergence is the chief culprit in the misalignment. The divergence is occurring above the area of convection, indicating that the low is developing a system for ventilating itself.

An analysis of vorticity shows that the system has positive vorticity at the 850 and 700 mb levels and that the two levels are basically aligned, which in a tropical cyclone (or proto-cyclone) is positive for development:

850 mb vorticity

700 mb vorticity

Shear is all right above the system but not especially favorable in the surrounding environment:

This is no surprise for this early in the season, but the National Hurricane Center expects the environment to become more favorable for this system in the next couple of days. An examination of the GFS model indicates that they are probably correct in this expectation; though shear is expected to be prohibitive of any tropical activity in the Gulf of Mexico, it is supposed to lighten up around the low pressure center.

Incidentally, the GFS doesn’t seem to do much with this cyclone other than letting it churn in place. Don’t expect a hurricane out of this! At best, I’d say it might rate a tropical depression. It is primarily an interesting feature to watch for so early in the season, a harmless storm that we tornado-weary weather folk can observe without anxiety. Tropical cyclogenesis is a fascinating, somewhat mysterious, and awe-inspiring phenomenon, and instances like this that are not the classic “Cape Verde wave in September starts to spin in the middle of the Atlantic” pattern are particularly interesting because the process of genesis for them is not cut-and-dry like the well-known central Atlantic tropical wave process is. This system may very well be a harbinger, but that remains to be seen. For now, it’s a neat feature to watch.

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 a degenerate “pop culture.” What have reality TV, bloodthirsty infotainment, and overnight Youtube “fame” for stupidity done to us? Apparently, they have produced a society straight out of Fahrenheit 451 (read it; it’s not only about burning books) or The Hunger Games. This is shameful.

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 heard 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, and this would include mandates to install underground shelter. I am opposed to it if subsidies were provided. I am even opposed to it if children are involved, because I don’t think the government has any business protecting children from their parents’ decisions unless those decisions violate a child’s human rights. There is simply way too much potential for nanny-state abuse of power if this particular door is opened. This must be a matter of personal responsibility. However, I am not opposed to rewarding the decision to install a storm shelter with a tax rebate or credit. We give away tax credits and rebates for all sorts of decisions, including some that are not universally agreed to be beneficial.

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.

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.

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.