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4B.5 Connecting the Dots: a Communications Model of the North Texas Integrated Warning Team During the 15 May 2013 Tornado Outbr

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4B.5 Connecting the Dots: a Communications Model of the North Texas Integrated Warning Team During the 15 May 2013 Tornado Outbr 4B.5 Connecting the Dots: A Communications Model of the North Texas Integrated Warning Team During the 15 May 2013 Tornado Outbreak 1* 2 1 1 Dennis Cavanaugh , Melissa Huffman , Jennifer Dunn , and Mark Fox 1National Weather Service Forecast Office Fort Worth/Dallas, TX 2National Weather Service Forecast Office Houston, TX On 15 May 2013, 19 tornadoes occurred across North and Central Texas, killing 6, injuring over 50, and causing more than $100 million in property damage. The majority of the impacts to life and property were the direct result of EF-3 and EF-4 tornadoes that affected the communities of Cleburne and Granbury. This study focuses on an examination of the North Texas Integrated Warning Team (IWT) communications through a thorough analysis of interactions between IWT members during this event. Communications from all members of the IWT were collected and organized so that a quantitative analysis of the IWT communications network could be performed. The results of this analysis were used to identify strengths and weaknesses of current IWT communications to improve the consistency of hazardous weather messaging for future high impact weather events. The results also show how effectively communicating within an IWT leads not only to more consistent messaging, but also to broader dissemination of hazardous weather information to the public. The analysis techniques outlined in this study could serve as a model for comprehensive studies of IWTs across the country. 1. INTRODUCTION media representatives, amateur radio operators, * and the National Weather Service (Doswell et al. On 15 May 2013, 19 tornadoes occurred 1999). IWTs work to provide a consistent message across North and Central Texas, killing 6, injuring regarding a hazard because at-risk populations over 50, and causing more than $100 million in will not immediately take action in response to the property damage (NCDC 2013). The majority of first warning message they hear (Sorensen 2000), the impacts to life and property from this outbreak but will instead seek out additional sources of were in the communities of Cleburne and warning information to confirm the warning is true Granbury. The Cleburne tornado, rated an EF-3, (Mileti and Sorensen 1990). Message damaged dozens of homes along an almost 9 mile inconsistency limits the ability of the at-risk path. The Granbury tornado, rated an EF-4, was population to personalize, or recognize the responsible for the outbreak’s six fatalities as it personal importance of, warning messages moved along a nearly 3 mile path. (Foster 1980). This, in turn, affects a much broader decision making process that culminates The warning system for hazardous weather, in the decision on whether or not to seek including events like the 15 May 2013 outbreak, protective action; the protective action decision consists of detecting an impending threat, making process consists of identifying a threat, providing information to those at risk, and enabling personalizing it, evaluating protection options and the at-risk population to make decisions for then making a decision on how to respond to the personal safety (Sorensen 2000). Agencies that threat (Lindell and Perry 1992, 2004). perform the hazard identification and communication functions of warning systems are This study focuses on a formal examination of IWT known as Integrated Warning Teams (IWTs). IWT communications with a thorough analysis of members are most commonly identified as local interactions between North Texas IWT members emergency management and government officials, during the 15 May 2013 tornado outbreak. Understanding the interactions of an IWT not only serves to identify the strengths and weaknesses of * Corresponding author’s address: Dennis Cavanaugh, current IWT hazardous weather messaging, but is 3401 Northern Cross Boulevard, Fort Worth, TX 76137 an important step in building a resilient community. E-mail: [email protected] Community resiliency, or the ability to respond and recover from a disaster, is not solely based on the operations of their respective Emergency post-disaster decisions, but the decisions leading Operations Centers, including the activation of up to the event (Nigg 1995). Communications from various methods of public notification of hazardous all members of the IWT during the 15 May 2013 weather (i.e. Outdoor Warning Sirens, and the outbreak were documented so that a quantitative activation of “Reverse 9-1-1” type of technologies). analysis of the IWT communications network could Media, EM, and VOST communications that be performed for this event. occurred within NWSChat were also documented, and VOST communications that occurred primarily 2. DATA AND METHODOLOGY on Twitter and Facebook were included in this study. Finally, communications that directly To perform a quantitative analysis of mentioned the NWS on Twitter (i.e. mentions of communications within the North Texas IWT @NWSFortWorth), and any direct Facebook (hereafter, simply IWT) during this event, the interactions between the NWS and Public were groups that compose the IWT had to be formally documented. To capture some idea of what defined. In this study, the IWT is composed of four message the public received during this event, primary groups: The National Weather Service door to door surveys were conducted near the Forecast Office in Fort Worth, TX (hereafter tornado damage paths of the Sunset, Granbury, NWS), the primary television broadcast media and Cleburne tornadoes. Only 29 individuals were outlets in the Dallas-Fort Worth area Designated available or willing to respond, so the Public Market Area (hereafter referenced as “Media”), survey results are not used directly as a point of North Texas local emergency management analysis in this study but provide anecdotal officials (hereafter referenced as “EM”), and a context. Amateur radio communications logs and Virtual Operations Support Team (hereafter, internal NWS communications logs were also VOST) (http://vosg.us/history). Each member of used to document communications with trained this IWT had a common goal of providing spotters and storm reports that were received from hazardous weather information to the general the public. These methods resulted in 1229 unique public during this event. The public is also pieces of information documented for analysis. included as a group in this analysis, and is simplistically defined to include those individuals in To analyze how various pieces of information were North Texas not included in the IWT as defined communicated within the IWT during the event, above. This very generic definition of the public pieces of information were traced through the IWT was made because the primary focus of this study in the same way that personal networks, or rumor is on internal IWT communications, and not a networks can be modeled, with a digraph (Poole detailed analysis on response behaviors to the 2011, Uzzi and Dunlap 2005). There were weather warning system as a whole. numerous pieces of information that could have been tracked in this study, however the following All available communications were documented items were subjectively chosen by the authors to during this event, with the primary focus on document: collecting communications during the times of 1900 CDT to 2200 CDT, when 14 tornadoes, 6 1. First NWS Tornado Warning for Hood instances of baseball sized or larger hail, and 7 County (that mentioned Granbury, the instances of damaging wind were reported to the location of the EF-4 tornado that NWS (Figure 1) (NCDC 2013). Communications resulted in 6 fatalities) were collected from time-stamped, archived NWSChat logs (https://nwschat.weather.gov), 2. NWS Tornado Warning for Johnson NWS internal communications logs, and interviews with each NWS staff member that worked during County that mentioned Cleburne (the this event. Media communications were location of a mile wide EF-3 tornado documented minute by minute by reviewing with no fatalities) archived tapes of coverage provided by the local ABC, CBS, NBC, and FOX affiliates of the Media. 3. NWS Tornado Warning issued for the EM communications were documented by Cleburne tornado shifting to a conducting semi-structured interviews with EM northward track officials in Montague, Hood, and Johnson Counties. These EM officials also provided a timeline of internal communications and 4. NWS Tornado Warning for Tarrant where i=j) had to be zeros. That is, a group does County not directly communicate with itself in this model. 5. The knowledge that the Cleburne Successful communication of a piece of information was defined as any communication of tornado’s track (Johnson County) was information items 1-13 that could be confirmed shifting north between members of the IWT with the data collected during this event. A successful 6. The knowledge of a tornado debris communication had to be verified within 15 signature in dual-polarization radar minutes of the piece of information entering the schematics on a supercell in Parker IWT by any means. The requirement for a direct County communication to occur within 15 minutes of entering the IWT was subjectively defined by the 7. The report that the Cleburne tornado authors, but was based on the advance tornado (Johnson County) was a “mile-wide warning lead time goal set by the National wedge” tornado Weather Service (NWS National Performance Measures, 2010). Each of the adjacency matrices 8. The confirmation report of a tornado in created in this event are included as Appendix A at the end of this paper. Granbury (Hood County) The collected data made the creation of the 9. The confirmation report of a tornado in adjacency matrices straightforward for the most Pecan Plantation (Hood County) part; however, there were occasions where verification of a successful communication link 10. The confirmation report of baseball was ambiguous. To reduce bias in the creation of sized hail in Granbury (Hood County) the adjacency matrices, each of the authors independently created adjacency matrices for 11. The confirmation report of a tornado in each piece of information (1-13) and then met to the Millsap area (Parker County) discuss discrepancies.
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