Springtime weather made an early appearance this past week, bringing warm weather, heavy rains and even strong storms to the Midwest. In certain areas of the country, spring means extreme weather and the occasional tornado. This week’s dataset looks at tornado records in the United States from 1950 through 1999.
During this time, the alert system for, and our understanding of, tornados evolved dramatically. The first recognized tornado forecast was made by Major E.J. Fawbush and Captain R.C. Miller at Tinker Air Force Base in Oklahoma in 1948. After evaluating weather conditions that caused an incredibly disruptive tornado only 5 days prior, and the conditions on March 25, 1948, they issued a warning for the base for that evening from 4:00pm to 6:00pm. As forecast, the conditions were favorable for tornadic activity and a tornado struck the base near 6:00pm. Despite the unpredictable nature of thunderstorms and associated tornadic activity, Fawbush and Miller were correct in issuing their warning.
The early 1950’s also saw vast improvements in the Weather Spotter Network, including more general use of spotters who had previously been used to warn military installations of impending weather. Technological advancements also came on the scene in the 50’s – the biggest being Radar. Born out of military necessity, radar’s ability to identify the “hook echo” signature of tornadic activity made it a valuable tool in forecasting severe weather across the nation.
Additional development of mechanisms to forecast tornados and severe weather proceeded through the decade, and in 1965 the tornado watch and tornado warnings that Midwesterners are familiar with were standardized. Around this time, and through the mid 1970’s, the dissemination of the warnings was also standardized. The National Weather Wire Service (now the NOAA Weather Wire Service) developed a teletype system to provide watch and warning products to radio and television stations in proximity to National Weather Service offices. Computer and satellite systems eventually replaced the teletype system and extended the reach of watches and warnings. The improvements led to the Emergency Alert System released in 1997.
While these developments were made in the warning systems, our fascination with tornados drove progress in forecasting severe weather and tornados. From advanced radar to a network of trained spotters to professional storm chasers, countless hours of research has been done on severe storms. The combination of this additional research and advances in warning systems has influenced the public’s awareness of imminent threats, undoubtedly saved lives.
With this background and the data set, what can you visualize? Remember to post your viz to Twitter, tagging @TThrowbackThurs with the hashtag #ThrowbackThursday.
This week's data comes from the NOAA National Centers for Environmental Information, Storm Events Database. Please be sure to credit the data source in your visualization.
Information for this week's post comes from the following reference: Coleman, Timothy A., et al. “The History (and Future) of Tornado Warning Dissemination in the United States.” Bulletin of the American Meteorological Society, vol. 92, no. 5, 2011, pp. 567–582., doi:10.1175/2010bams3062.1.
Information on the columns for the data source can be found here. Note that there are some questionable longitudes and latitudes in the dataset. In the interest of maintaining the original data, we did not make any attempt to correct these. Additionally, there are several tornados for which there are null Fujita ratings. We considered these unrecorded, and indicated as such in our visualizations.