PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Twister history: FSU researchers develop model to correct tornado records for better risk assessment

2013-09-13
(Press-News.org) TALLAHASSEE, Fla. — In the wake of deadly tornadoes in Oklahoma this past spring, Florida State University researchers have developed a new statistical model that will help determine whether the risk of tornadoes is increasing and whether they are getting stronger.

Climatologists have been hampered in determining actual risks by what they call a population bias: That is, the fact that tornadoes have traditionally been underreported in rural areas compared to cities.

Now, FSU geography Professor James B. Elsner and graduate student Laura E. Michaels have outlined a method that takes the population bias into account, as well as what appears to be a recent surge in the number of reported tornadoes, thanks in part to an increasing number of storm chasers and recreational risk-takers roaming Tornado Alley.

Their model is outlined in the article "The Decreasing Population Bias in Tornado Reports across the Central Plains," published in the American Meteorological Society's journal Weather, Climate, and Society. The model offers a way to correct the historical data to account for the fact that there were fewer reports in previous decades. In addition to Elsner and Michaels, Kelsey N. Scheitlin, an assistant professor at the University of Tennessee at Knoxville, and Ian J. Elsner, a graduate student at the University of Florida, co-authored the paper.

"Most estimates of tornado risk are probably too low because they are based on the reported number of tornadoes," Elsner said. "Our research can help better quantify the actual risk of a tornado. This will help with building codes and emergency awareness. With our research, the science of tornadoes can move forward to address questions related to whether cities enhance or inhibit tornadoes."

Although other researchers have proposed methods to address the population bias, all of them assume the bias is constant over time, Elsner said. This model is the first to take into consideration how the population bias has changed over time.

Historically, the number of reported tornadoes across the premiere storm chase region of the central Plains is lowest in rural areas. However, the number of tornado reports in the countryside has increased dramatically since the 1970s and especially since the 1996 release of the disaster movie "Twister." The movie spawned a generation of storm chasers who are partially responsible for more tornado reports, Elsner said.

Interestingly, Elsner's model was developed after he led a team of undergraduate and graduate students on a storm-chasing mission of their own.

"While we were driving around the Great Plains looking for storms, I challenged my students to think about how the historical data could be used to better estimate the risk of getting hit by a tornado," he said. "The observations of other chasers and the geographic spacing of towns led us to our model for correcting the historical record."

In addition to more storm chasers logging tornado sightings, greater public awareness of tornadoes and advances in reporting technology, including mobile Internet and GPS navigating systems, may also have contributed to the increase in reports over the past 15 to 20 years.

The increase in reports has diminished the population bias somewhat, but it introduced a second problem: There are more reports, but are there also, in fact, more tornadoes? In other words, is the risk actually increasing?

To address these issues, the FSU researchers first made the assumption that the frequency of tornadoes is the same in cities as in rural areas. They also operated on the assumption that the reported number of tornadoes in rural areas is low relative to the actual number of tornadoes.

Their model calls for the reported number in rural areas to be adjusted upward by a factor that depends on the number of tornadoes in the nearest city and the distance from the nearest city. The model shows that it is likely that tornadoes are not occurring with greater frequency, but there is some evidence to suggest that tornadoes are, in fact, getting stronger.

"The risk of violent tornadoes appears to be increasing," Elsner said. "The tornadoes in Oklahoma City on May 31 and the 2011 tornadoes in Joplin, Mo., and Tuscaloosa, Ala., suggest that tornadoes may be getting stronger."

The Oklahoma City tornado on May 31, 2013, was the largest tornado ever recorded, with a path of destruction measuring 2.6 miles in width. The Tuscaloosa and Joplin tornadoes are two of the most deadly and expensive natural disasters in recent U.S. history.

###

END



ELSE PRESS RELEASES FROM THIS DATE:

Underlying ocean melts ice shelf, speeds up glacier movement

2013-09-13
Warm ocean water, not warm air, is melting the Pine Island Glacier's floating ice shelf in Antarctica and may be the culprit for increased melting of other ice shelves, according to an international team of researchers. "We've been dumping heat into the atmosphere for years and the oceans have been doing their job, taking it out of the air and into the ocean," said Sridhar Anandakrishnan, professor of geosciences, Penn State. "Eventually, with all that atmospheric heat, the oceans will heat up." The researchers looked at the remote Pine Island Glacier, a major outlet ...

Scripps Florida scientists pinpoint proteins vital to long-term memory

2013-09-13
JUPITER, FL – September 12, 2013 – Scientists from the Florida campus of The Scripps Research Institute (TSRI) have found a group of proteins essential to the formation of long-term memories. The study, published online ahead of print on September 12, 2013 by the journal Cell Reports, focuses on a family of proteins called Wnts. These proteins send signals from the outside to the inside of a cell, inducing a cellular response crucial for many aspects of embryonic development, including stem cell differentiation, as well as for normal functioning of the adult brain. "By ...

Voyager 1 spacecraft reaches interstellar space

2013-09-13
University of Iowa space physicist Don Gurnett says there is solid evidence that NASA's Voyager 1 spacecraft has become the first manmade object to reach interstellar space, more than 11 billion miles distant and 36 years after it was launched. The finding is reported in a paper published in the Sept. 12 online issue of the journal Science. "On April 9, the Voyager 1 Plasma Wave instrument, built at the UI in the mid-1970s, began detecting locally generated waves, called electron plasma oscillations, at a frequency that corresponds to an electron density about 40 times ...

Voyager 1 spotted from Earth with NRAO's VLBA and GBT telescopes

2013-09-13
Astronomers using the National Science Foundation's (NSF) Very Long Baseline Array (VLBA) and Green Bank Telescope (GBT) spotted the faint radio glow from NASA's famed Voyager 1 spacecraft -- the most distant man-made object. According to NASA's Jet Propulsion Laboratory (JPL), the VLBA imaged the signal from Voyager 1's main transmitter after the spacecraft had already passed beyond the edge of the heliosphere, the bubble of charged particles from the Sun that surrounds our Solar System. Using NASA's Deep Space Network, JPL continually tracks Voyager and calculates ...

Toxic methylmercury-producing microbes more widespread than realized

2013-09-13
Microbes that live in rice paddies, northern peat bogs and other previously unexpected environments are among the bacteria that can generate highly toxic methylmercury, researchers at Oak Ridge National Laboratory and the Smithsonian Environmental Research Center have learned. This finding, published in Environmental Science and Technology, explains why deadly methylated mercury is produced in areas where the neurotoxin's presence has puzzled researchers for decades. Methylmercury — the most dangerous form of mercury — damages the brain and immune system and is especially ...

Trans-Nino years could foster tornado super outbreaks

2013-09-13
Alexandria, VA – One tornado can be damaging enough; severe weather systems that spawn hundreds of deadly tornadoes in super-outbreaks pose special challenges to the scientific and emergency management communities. Now, scientists have identified certain conditions in the Pacific Ocean that may lead to super-outbreaks over the U.S.' tornado alley. Researchers are trying to determine if Trans-Niño years, which mark the onset or ebbing of El Niño and La Niña, are the main culprits behind the deadly super-outbreaks. According to the study, fueled by a powerfully interconnected ...

Esteem issues determine how people put their best Facebook forward

2013-09-13
How social media users create and monitor their online personas may hint at their feelings of self-esteem and self-determination, according to an international team of researchers. "The types of actions users take and the kinds of information they are adding to their Facebook walls and profiles are a refection of their identities," said S. Shyam Sundar, Distinguished Professor of Communications and co-director of the Media Effects Research Laboratory, Penn State. "You are your Facebook, basically, and despite all its socialness, Facebook is a deeply personal medium." People ...

Research shows denser seagrass beds hold more baby blue crabs

2013-09-13
When it comes to nursery habitat, scientists have long known that blue crabs prefer seagrass beds compared to open areas in the same neighborhood. A new study by researchers at William & Mary's Virginia Institute of Marine Science refines that knowledge, showing that it's not just the presence of a seagrass bed that matters to young crabs, but also its quality—with denser beds holding exponentially more crabs per square meter than more open beds where plants are separated by small patches of mud or sand. The study, led by VIMS graduate student Gina Ralph, appeared recently ...

Exposure/ritual prevention therapy boosts antidepressant treatment of OCD

2013-09-13
NIMH grantees have demonstrated that a form of behavioral therapy can augment antidepressant treatment of obsessive compulsive disorder (OCD) better than an antipsychotic. The researchers recommend that this specific form of cognitive behavior therapy (CBT) – exposure and ritual prevention – be offered to OCD patients who don't respond adequately to treatment with an antidepressant alone, which is often the case. Current guidelines favor augmentation with antipsychotics. In the controlled trial with 100 antidepressant-refractory OCD patients, 80 percent of those who ...

Medicare Center of Excellence Policy may limit minority access to weight-loss surgery

2013-09-13
Safety measures intended to improve bariatric surgery outcomes may impede obese minorities' access to care. This is according to a new research letter published online in the September 12 issue of JAMA which compares rates of bariatric (weight-loss) surgery for minority Medicare vs. non-Medicare patients before and after implementation of a Medicare coverage policy. The policy limits Medicare patients seeking bariatric surgery to high-volume hospitals designated as centers of excellence. Led by faculty from the Johns Hopkins Bloomberg School of Public Health, the researchers ...

LAST 30 PRESS RELEASES:

AI can spot which patients need treatment to prevent vision loss in young adults

Half of people stop taking popular weight-loss drug within a year, national study finds

Links between diabetes and depression are similar across Europe, study of over-50s in 18 countries finds

Smoking increases the risk of type 2 diabetes, regardless of its characteristics

Scientists trace origins of now extinct plant population from volcanically active Nishinoshima

AI algorithm based on routine mammogram + age can predict women’s major cardiovascular disease risk

New hurdle seen to prostate screening: primary-care docs

MSU researchers explore how virtual sports aid mental health

Working together, cells extend their senses

Cheese fungi help unlock secrets of evolution

Researchers find brain region that fuels compulsive drinking

Mental health effects of exposure to firearm violence persist long after direct exposure

Research identifies immune response that controls Oropouche infection and prevents neurological damage

University of Cincinnati, Kent State University awarded $3M by NSF to share research resources

Ancient DNA reveals deeply complex Mastodon family and repeated migrations driven by climate change

Measuring the quantum W state

Researchers find a way to use antibodies to direct T cells to kill Cytomegalovirus-infected cells

Engineers create mini microscope for real-time brain imaging

Funding for training and research in biological complexity

The Journal of Nuclear Medicine Ahead-of-Print Tip Sheet: September 12, 2025

ISSCR statement on the scientific and therapeutic value of human fetal tissue research

Novel PET tracer detects synaptic changes in spinal cord and brain after spinal cord injury

Wiley advances Knowitall Solutions with new trendfinder application for user-friendly chemometric analysis and additional enhancements to analytical workflows

Benchmark study tracks trends in dog behavior

OpenAI, DeepSeek, and Google vary widely in identifying hate speech

Research spotlight: Study identifies a surprising new treatment target for chronic limb threatening ischemia

Childhood loneliness and cognitive decline and dementia risk in middle-aged and older adults

Parental diseases of despair and suicidal events in their children

Acupuncture for chronic low back pain in older adults

Acupuncture treatment improves disabling effects of chronic low back pain in older adults

[Press-News.org] Twister history: FSU researchers develop model to correct tornado records for better risk assessment