Although some research has found that since 1950 there has been a measurable increase in tornado frequency in the USA, this finding could be largely due to better detection and reporting techniques that have occurred over the decades. On the other hand, this finding could be due to changing macro-climatic conditions that make extreme weather events, such as tornadoes, occur with more frequency and intensity. There is no strong evidence to support severe weather becoming stronger, more frequent or more widespread during the past 50 years; or more importantly, predicted for the next 50 years in the United States. There is also no strong evidence for weather events to become less frequent or less severe either. One of the reasons that the change in severe weather is hard to track is the fact that the reporting systems have changed so much over time. Nonetheless, recent extreme weather, including the notable outbreaks in El Reno, Okla., Moore, Okla., and Washington, Ind., last year forced the debate of the impact of climate change on severe weather to resurface (and I can forecast that the debate will probably continue in the coming year). While there has been research into this subject, there are still many unknowns and like the weather itself, it remains difficult to predict the outcome of these debates with any absolute certainty.
While the long term changes in frequency and intensity of weather-related events remains to be seen, it seems reasonable and prudent to at least acknowledge that in the short term the threats from severe weather events, particularly tornadoes, is a risk for which everyone should be prepared and ready to mitigate and manage.
Tornadoes are fast moving violent storms. They occur when conditions are favorable (often in connection with thunderstorms) for their formation and they can threaten property and people.
According to the website Weatherbug.com, tornadoes were the second leading cause of weather-related fatalities in the U.S. during the past decade. The site reports that three out of four tornadoes worldwide occur in the U.S., averaging about 1,200 tornadoes each year. A tornado may have top wind speeds of up to 300 miles per hour (MPH). Tornadoes have occurred in every U.S. state and have resulted in 1,145 deaths in the last 10 years.
A tornado’s destructive path of damage paths can exceed more than a mile’s width and can stretch for up to 50 miles long. One challenge of tornadoes, compared with other dangerous weather related threats, is that they develop quickly with little to no advance warning. This makes the challenge of alerting at-risk populations particularly problematic. According to the National Oceanic and Atmospheric Administration (NOAA) the current average lead-time for tornado warnings is 13 minutes. NOAA Research is working to increase tornado warning lead-times much further but the need for effective and rapid warning notification remains acute.
Tornado Warnings Challenges
Tornadoes are one of the most difficult to predict weather-related occurrences. This prediction difficulty is due to a number of factors, but include interactive chaotic tornadic genesis variables within thunderstorms, short-life duration of typical tornado life cycle, the scale and scope of storm systems that spawn tornadoes and a lack of reliable advance warning predictive models. These aspects, when combined with the fact that we simply do not (as of yet) recognize the distinctive trigger agent that allows an apparent identical set of variables to produce a tornado on one hand and many more that do not, making advance exact predictive forecasting of a tornado little more than educated guesswork. For the most part, we have to wait until a tornado has formed before we are aware that there is one threatening. This means that we are limited to very short time frames from when we recognize a tornado’s existence, we project a potential path and getting warning notifications out to the threatened “at risk” areas.
Adrienne LaFrance recently wrote an essay titled Supercomputers, Tornadoes and the Biggest Unsolved Mystery in Weather Technology in The Atlantic that:
“Predicting tornadoes is so difficult that many people still rely on natural warning signs and folklore. Sky the color of pea soup, eerie stillness, and thundering hailstones are all ominous tornado warning signs. But none of these conditions, alone or together, guarantees a tornado is imminent. Not even the best weather-forecasting technology can determine more than a few minutes ahead of time whether a tornado will strike. By the time a tornado has touched down, it’s often too late for people to reach safety. …. Even as forecasting technology has made remarkable advances in recent decades, tornadoes are an outlier. They remain dangerously difficult to see coming.”
Francie Diep comments on the time challenge in a Popular Science article Why Are Tornadoes So Hard To Predict? People in the path of a tornado typically get only 10 minutes of warning. Why? :
“Sixteen minutes before a tornado touched down in Newcastle, Okla., yesterday, the U.S. Storm Prediction Center sent a warning to the area. That heads-up was longer than the average warning time of 8 to 10 minutes…. Hurricanes and blizzards show up on satellites days beforehand, but the conditions that favor tornadoes appear much more quickly and unexpectedly, the Associated Press reported in 2011. Tornadoes are just made of much finer print, so to speak. Their paths are smaller and they last for shorter periods of time, so predicting any particular tornado requires a fine-grain understanding that's more difficult for scientists.”
Tornadoes are notorious for the short time frame from forecasters knowing something about a tornado and getting the emergency warning to the people most likely affected. On average, there is only about 10 minutes from when experts realize a tornado is threatening until it subsequently strikes a given location. Getting the warning out to the right people, at the right time, in the right way is of paramount importance for effective tornado warnings notification success.
LaFrance continues in the Atlantic article writing:
“Today, officials issue a tornado watch when weather conditions mean a tornado is possible, and they issue a tornado warning when a tornado has actually been spotted. The difference, as the National Weather Service puts it, is that a watch means you should be prepared to take action, and a warning means you should take action immediately. Even if someone is alerted to a tornado warning the moment it’s issued, there’s little time to seek shelter. Officials put out a warning 16 minutes before the tornado that decimated Moore, Oklahoma, in 2013, touched down and killed 24 people. Two years before that, in Joplin, Missouri, sirens sounded 20 minutes before the catastrophic twister touched down and killed 158 people…..Today, forecasters are able to give closer to 14 minutes notice before a tornado touches down—but not in every case.”
The National Weather Service (NWS) relies on a multi-tiered alert classification scheme to help adjust to this narrow time frame warning window. A tornado watch is issued when conditions are right for the formation of tornadoes. A tornado warning is issued when a tornado has been identified on radar or visually verified by weather spotters. A warning can be issued with or without a tornado watch being already in effect. A tornado warning is issued by a local National Weather Service office (NWFO) and includes where the tornado was located, when, which direction it is moving and what lies in its path.
New Tools and Technology can Enhance Tornado Warning Notification
While it may not be scientifically possible to significantly increase the advance prediction time for a tornado strike, modern communication technology and communication tools can help improve the speed, effectiveness and precision of emergency notification messages to those threatened by tornadoes.
Once the local, regional and national office warnings have been issued, the clock is running on alerting people in the potential pathway of the moving tornado. So, getting the word from the officials to your key-targeted people, including employees, customers, vendors, suppliers, constituents, partners and others becomes the link in the communication chain where fast, effective and accurate communication can make the most difference. So what is the best way to get the warnings from the weather officials to your important audience?
The importance of systematic, reliable and fast severe weather monitoring (SWM) capabilities cannot be over-stated. Businesses, schools, healthcare facilities, corporations, agencies, building or campus managers, retail and entertainment venue management and many other organizations need to be comprehensively connected to both the source of weather warning information and to those whom they need to pass along this vitally important notification. The communication process and protocols should be fast, accurate, dependable and reliable.
Automatic and geographically precise severe weather monitoring (SWM) and warning notification systems and services are a key for rapidly bridging the receipt and transmission of tornado warning notification messages. It is essential to have a comprehensive solution that includes around-the-clock monitoring and alerting for severe weather events throughout the U.S. The system and service should notify your target audiences whenever severe weather is targeting their specific location.
To achieve the highest measure of accuracy, the system should be tied directly into the National Weather Service's Storm Based Warning System to interpret weather bulletins and use reliable methods to generate geographically targeted notifications. Messages should initiate automatically by the system as a service, with no need for human mediation if at all possible - providing important extra time for warnings to reach the intended audiences and to allow them to understand, process and react appropriately. It is also essential to use a high-speed outbound notification system capable of broadcasting warning notifications via voice, text, email and have a capacity for automated survey messages to gauge behavioral compliance and updated status.
High-speed notification is one of the most powerful tools available to management in tornado and severe weather notification tasks. The ability to deliver hundreds or thousands of messages easily to your employees/team members and other constituents within seconds makes the difference when trying to provide adequate warnings in a compressed period, like the tornado warning life cycle. Since tornadoes and other weather events can strike at any time of the day or night, the system should also be easy to launch messages from any phone, smart device or web connected computer.
The Storm Prediction Center has a webpage of tornado safety tips, many geared toward the short lead times that people typically have before a twister.
National warnings are available from NWS NOAA
Images: NOAA; Brokerexclusive; Scriptnet; IndianaWeatherOnline