Tornadoes Unveiled: Understanding the Impact and Safeguarding Your Business and Community
According to data from NOAA’s Storm Prediction Center, during 2022, there were 1,329 preliminary tornado reports and 23 deaths. During the most prolific tornado months of 2022, there were 100 or more tornadoes reported per month. As our climate changes and severe weather events such as tornadoes become more volatile, it is important to understand what they are and how we can better prepare for them.
Tornado Basics
A tornado is a rotating, funnel-shaped cloud that extends from a thunderstorm to the ground with violent winds that can reach in excess of 300 miles per hour. Damage paths can be over a mile wide and 50 miles long. The average ground speed is 30 mph but may vary from nearly stationary to 70 mph. Occasionally, tornadoes develop so rapidly that advanced warning can be difficult. (Missouri Storm Aware)
They generally occur near the trailing edge of a thunderstorm and can accompany hurricanes as they move onto land. In fact, more than half of hurricanes produce at least one tornado after making landfall. (WRAL) In 2020, Hurricane Isaias spawned 12 tornadoes in North Carolina. The strongest was an EF-3 in Bertie County that killed two people. (WRAL) The most tornadoes spawned by a single hurricane were associated with Hurricane Ivan, which spawned 120 tornadoes in September of 2004.
Tornadoes are most likely to occur between 3 pm and 9 pm but can occur at any time. Before a tornado hits, the wind may die down and the air may become very still. A cloud of debris can mark the location of a tornado even if a funnel is not visible. It is not uncommon to see clear, sunlit skies behind a tornado. (Missouri Storm Aware)
These violent storms occur around the world, but the United States is a major hotspot with about a thousand tornadoes every year. “Tornado Alley” is a nickname given to the area in the southern plains of the central U.S. that expects a high frequency of tornadoes each year. The area includes the eastern area in the state of South Dakota, Nebraska, Kansas, Oklahoma, northern Texas, and eastern Colorado. Tornadoes in this region typically happen in late spring and occasionally in the early fall. (National Geographic)“
77% of tornadoes in the U.S. are considered weak (EF0 or EF1) and about 95% of U.S. tornadoes are ranked below EF3. The remaining minority of tornadoes are categorized as violent (EF3 and above). Of these violent twisters, only a few (0.1%) become EF5 strength, with estimated winds over 200 mph and nearly complete destruction. However, given that on average over 1,000 tornadoes hit the U.S. each year, this means that 20 of these can be expected to be violent and one could possibly be incredible (EF5). (Missouri Storm Aware)
Impacts of Tornadoes
Tornadoes are different from other hazards, like hurricanes, because they are restrained to a somewhat small area (usually a few 100m wide). However, its higher force density enables it to wreak great havoc on the area and its travel routes can be unpredictable and indiscriminate.
Even if you have been lucky enough not to be directly impacted by a tornado, you have likely recently heard or seen their effects on other locations on the news. Their visible impacts can be extreme: Tornadic winds tear homes and businesses apart, destroy bridges, flip trains, send cars and trucks flying, tear the bark off trees, and even suck all the water from a riverbed.
Tornadoes sometimes kill or injure people by rolling them along the ground or dropping them from dangerous heights (National Geographic). On average, these twisters cause an average of 70 fatalities and 1,500 injuries in the U.S. each year (Missouri Storm Aware).
Tornadoes also cause pollution and environmental contamination. Like other severe weather events, the destruction caused by tornadoes often releases or stirs up contaminants in the environment. Dust and other air contaminants can be brought in from dryer areas that can cause issues for individuals with respiratory or heart issues. Damage from tornadoes can lead to leaks in vehicles, chemical containers, and pipelines causing oil, asbestos, dioxides, raw sewage, industrial waste, and medical wastes to be released into the surrounding land and groundwater.
The financial losses from tornadoes can also be significant. Consider the damage caused by three-second wind gusts at over 200 mph during the tornado that ripped through Joplin, Missouri, in May 2011. Over 8,000 buildings were flattened, 161 fatalities occurred, and more than 1,000 people were injured. After all that damage was added up, the Joplin tornado cost $2.8 billion, making it not only one of the deadliest on record in the United States, but also the costliest. (Investopedia)
Direct losses result from the destruction of assets from the initial impact of the tornado and include the loss of human lives, roads, power, phone lines, crops, factories, homes, and natural resources. Indirect losses include lost production and sales, incomes and labor time, increased commute times, increased transportation costs from goods having to be rerouted, decreased tourist activity, and utility disruptions. Lost production can also result in surging prices due to consequent shortages. Increased tornado activity can also lead to permanently higher insurance premiums or reduced coverage. (Investopedia)
Tornado Frequency
A study published recently in NPJ Climate and Atmospheric Science, by Vittorio A. Gensini of Northern Illinois University and Harold E. Brooks of the National Severe Storms Laboratory, looked into the possibility that tornado frequencies are changing across the United States. Their findings include a decrease in the traditional “Tornado Alley” of the Great Plains and an increase in the Southeast’s “Dixie Alley”. (National Weather Service)
A significant upward trend in tornado frequency was found in portions of the Southeast, Midwest, and Northeast. Both tornado reports and tornado environments indicate an increasing trend in portions of Mississippi, Alabama, Arkansas, Missouri, Illinois, Indiana, Tennessee, and Kentucky. (National Weather Service)
While there have been no long-term trends in the frequency of tornadoes, there have been changes in tornado patterns in recent years. Research has shown that there are fewer days with at least one tornado but more days with over thirty, even as the total number of tornadoes per year has remained relatively stable. In other words, tornado events are becoming more clustered. (National Geographic).
Tornado Detection Needs an Upgrade
While tornado frequency may remain constant for now, reports suggest they are happening in closer proximity to each other and have more strength (National Geographic). This is concerning considering the gaps in weather data that we covered in our previous blog post Are Voids in Radar Coverage Leaving You Blind?
As we mentioned in that blog post, tornadoes can be one of the weather events that can go undetected. “Tornadoes can also remain undetected in these radar gaps. Rich Thompson, a meteorologist at NOAA’s Storm Prediction Center in Norman, Okla., is involved in research that shows that tornado warning performance “generally drops off once you go beyond about 50 [nautical miles] from the radar (or above about 4,000 ft),” (Washington Post). Thompson additionally noted “It would certainly be easier to detect possible tornadoes more consistently if we had radar coverage that allowed us to see the low levels everywhere,” (Washington Post).
Radar Scientists at Climavision estimate that with our network of radars deployed, the percentage of radar-detected tornadoes will double from 30 to 60% of tornadoes. Additionally, we calculated related fatalities for tornado events and estimate 30% of the fatalities occurred in NEXRAD low level radar data voids that Climavision is helping to fill.
Dangerous destructive weather events such as tornadoes make fast, accurate weather data crucial. When it comes to the safety of entire communities, gaps in coverage can be deadly. Businesses, emergency management agencies, and other government agencies need the best weather data to quickly and confidently detect tornadoes and warn communities in the storm’s destructive path. Contact us to learn how Climavision’s radar solutions may benefit your organization or community.
