“Italian codified hashtags for weather warning on Twitter. Who is really using them?

During emergencies increasing numbers of messages are shared through social media platforms, becoming a primary source of information for lay people and emergency managers. Weather service and institutions have started to employ social media to deliver weather warnings even if sometimes this communication lacks in strategy. In Twitter, for example, hashtagging is very important to associate messages to certain topics; in recent years codified hashtagging is emerging as a practical way to coordinate Twitter conversations during emergencies and quickly retrieve relevant information. In 2014 a syntax for codified hashtags for weather warning was proposed in Italy: a list of 20 hashtags, realized by combining #allertameteo (weather warning)+XXX, three letters for regional identification; the regional reference is connected to the organization of the Italian civil protection system based on the Regions. The widespread of codified hashtags has only been based on users’ commitment, institutions or citizens, to improve communication during disasters. In Tuscany Consorzio LaMMA, the regional public weather service, firstly adopted the hashtag on January 2014, publishing a Social Media Policy and promoting its use when warning are issued. In other regions codified hashtagging has been employed only by citizens, in other context it’s not yet used at all. This contribution presents a monitoring of Twitter usage of weather warning codified hashtags in Italy (since July 2015) and an analysis of more successful context. Twitter messages containing the codified hashtags were retrieved using the TwitterVigilance, a multi-users platform to crawl Twitter, collect and store messages and perform quantitative analytics, about users, hashtags, tweets/retweets volumes, and qualitative analysis through Natural Language Processing features. The codified hashtags dataset is presented and discussed with main analytics and evaluation of regional context where it was employed successfully. Examples of some case of severe weather events are presented