Growing Risk for Mobile Homes

Dangerous mix: Climate change, tornadoes, and mobile homes.

Tornadoes and mobile homes do not mix to begin with, but throw in the volatility of climate change and the potential for massive property damage and deaths is even higher in coming decades. The number of mobile homes in the United States has risen dramatically in the past 60 years, to about 9 million currently. Meanwhile, the United States is the most tornado-prone country in the world, with an average of 1,200 twisters per year.

The annual impact of tornadoes is expected to increase threefold over the next few decades due to the “twin forces of increased climate variability and growth in the human-built environment,” according to the study, which is published online in the journal Regional Science and Urban Economics.

More Frequent Large-Scale Tornadoes Expected

Recent postings have dealt with the likelihood of more frequent floods and now we have this citation of research on tornadoes.  It does seem that EM is a a field of endeavor likely to grow.

From HSNewswire, Tornadoes:More frequent large-scale tornado outbreaks.

The frequency of large-scale tornado outbreaks is increasing in the United States, particularly when it comes to the most extreme events, according to new research. The researchers found that the increase in tornado outbreaks does not appear to be the result of a warming climate as earlier models suggested. Instead, their findings tie the growth in frequency to trends in the vertical wind shear found in certain supercells—a change not so far associated with a warmer climate.

Some Basic Tornado Science – from National Geographic

It is too early to get details about magnitude and special characteristics of the spate of tornadoes the U.S. is experiencing at the present time. But when more is know, I will discuss why they were so deadly. Determining the magnitude of tornadoes is possible only after the fact, when scientists can actually examine the impacted area.

In the meantime, for some basic science info, see this article on the basics of the hazard and why forecasting them is so difficult.

Updates:  Here is one early account of the first tornadoes of this season in the U.S. See Eerie Calm Preceded Violent Swarm of Super Cells. [Thanks to Pierre Picard for this link.]

The tornadoes are still active for the third day over the same large region of the U.S. See this article in the Christian Science Monitor. Just one more unusual aspect of this outbreak of storms.


Observations on Moore, OK Tornado

The Diva and co-author Ann Patton wrote a article for Emergency Magazine on the Moore, OK tornado. Go to this site for the article titled OK Tornado Prompts Discussions on Surviving, Rebuilding, in the July/August edition of the magazine.

Some Tornado Facts and Myths

One of several tornadoes observed by the VORTE...

After the two major sets of tornadoes that were so devastating in OK in late May, this is a good time to review some facts and myths about tornadoes.  See this summary sheet on Tornado Facts and Myths from FLASH – the Federal Alliance for Safe Homes.

Also, here is a related story on the relationship between construction practices and damage after a tornado. Some excerpts from that article:

Damage costs are rising because of increased population density, even in mostly rural states such as Oklahoma, which has seen substantial urban sprawl in the last decade, said Greg Carbin, Warning Coordination Meteorologist for the National Weather Service’s Storm Prediction Center in Norman, Oklahoma.

Another important reason that has received less attention, is that most homes in tornado alley are not built to withstand even a modest tornado.

The result is that residents of tornado alley, insurance companies and the U.S. government are footing a mounting bill from damage that could be limited with better construction, according to several engineers, meteorologists and consumer advocates interviewed by Reuters.

“We have to stop this cycle of a storm coming along destroying things and we build them back the same,” said Leslie Chapman-Henderson, chief executive of the Federal Alliance for Safe Homes, a consumer group. “That is the official definition of insanity.”

Oklahoma should follow the example of Florida after Hurricane Andrew in 1992 and adopt a tougher building code to reduce damage in future, said Prevatt, Assistant Professor of Civil and Coastal Engineering at the University of Florida.

Joplin, MO — a useful model for recovery

Joplin as a model recovery example and one of the useful features of their efforts is the exemplary website the city has produced; see:

I ran across it while trying to determine how Joplin is doing two years after its devastating tornado disaster event.  See this Fact Sheet for basic info re Joplin the damage, impacts, and outcomes of recovery.

I wish every city engaged in disaster recovery did this.  We would finally have the basis for some serious case studies, and cross case comparisons needed to build a significant recovery knowledge base.

Some Tornado Science and History

Tornado Alley

Tornado Alley

NBC has done a nice job explaining some of the science behind the OK city tornado outbreaks.  And they provide an interesting chart that compares the current events with the deadly tornadoes of 1999, which is the frame of reference for many people in OK. The article is titled Curse or coincidence? Scientists study Tornado Alley’s past and future


I never get the kind of info I want from the news accounts. Since OK is centrally located in Tornado Alley, I would like to know things like:

  • what type of building/construction codes were in place in OK City?
  • what percentage of the population had a storm cellar or a safe room in their house?
  • how much tornado preparedness information and/or training was provided locally?


It is worth citing the quote from the Christian Science Monitor that I mentioned in May 2011, right after the devastating Joplin, MO tornadoes:

Yet the stunning death tolls from tornadoes this spring raise new questions about government subsidies for storm shelters, the psychology of warning response, the possibility of limited tornado evacuations, and the argument that tornado warning and response should be considered a national security issue.

One Year Anniversary of Deadly Tornado Outbreak

EF4-rated tornado damage in Ringgold, Georgia ...

EF4-rated tornado damage

From the HSDL, on April 26: 1 Year Anniversary of April 25-28, 2011 Tornado Outbreak. It was the 3rd most deadly tornado event in US history. Some details from the article:

Nearly one year ago today the third largest tornado outbreak in US history (since systematic tornado record keeping began in 1950) was recorded on April 25-28, 2011. The areas most affected by the devastating tornadoes included the Southern, Midwestern, and Northeastern United States. In particular, Alabama, Arkansas, Georgia, Mississippi, Tennessee, North Carolina and Virginia were hit hardest. According to a Department of Commerce Service Assessment report, more than 200 tornadoes occurred in the aforementioned states which resulted in 316 deaths, 2,400 injuries and over $4.2 billion in property damage. Out of the 200 tornadoes, 15 were considered to be EF4 to EF5 (Enhanced Fujita Scale 4 or 5) tornadoes. Note: The two deadliest tornado outbreaks ever recorded include the 1974 Super Tornado Outbreak (368 deaths) and the 1965 Palm Sunday Tornado Outbreak (337 deaths).