Tweeting in the Rain, Part 3

(This is part 3 of our series looking at how social data can create a signal about major rain events. Part 1 examines whether local rain events produce a Twitter signal. Part 2 looks at the technology needed to detect a Twitter signal.) 

What opportunities do social networks bring to early-warning systems?

Social media networks are inherently real-time and mobile, making them a perfect match for early-warning systems. A key part of any early-warning system is its notification mechanisms. Accordingly, we wanted to explore the potential of Twitter as a communication platform for these systems (See Part 1 for an introduction to this project).

We started by surveying operators of early-warning systems about their current use of social media. Facebook and Twitter were the most mentioned social networks. The level of social network integration was extremely varied, depending largely on how much public communications were a part of their mission. Agencies having a public communications mission viewed social media as a potentially powerful channel for public outreach. However, as of early 2013, most agencies surveyed had minimal and static social media presence.

Some departments have little or no direct responsibility for public communications and have a mission focused on real-time environmental data collection. Such groups typically have elaborate private communication networks for system maintenance and infrastructure management, but serve mainly to provide accurate and timely meteorological data to other agencies charged with data analysis and modeling, such as the National Weather Service (NWS). Such groups can be thought of being on the “front-line” of meteorological data collection, and have minimal operational focus on networks outside their direct control. Their focus is commonly on radio transmissions, and dependence on the public internet is seen as an unnecessary risk to their core mission.

Meanwhile, other agencies have an explicit mission of broadcasting public notifications during significant weather events. Many groups that operate flood-warning systems act as control centers during extreme events, coordinating information between a variety of sources such as the National Weather Service (NWS), local police and transportation departments, and local media. Hydroelectric power generators have Federally-mandated requirements for timely public communications. Some operators interact with large recreational communities and frequently communicate about river levels and other weather observations including predictions and warnings. These types of agencies expressed strong interest in using Twitter to broadcast public safety notifications.

What are some example broadcast use-cases?

From our discussions with early-warning system operators, some general themes emerged. Early-warning system operators work closely with other departments and agencies, and are interested in social networks for generating and sharing data and information. Another general theme was the recognition that these networks are uniquely suited for reaching a mobile audience.

Social media networks provide a channel for efficiently sharing information from a wide variety of sources. A common goal is to broadcast information such as:

  • Transportation Information about road closures and traffic hazards.

  • Real-time meteorological data, such as current water levels and rain time-series data.

Even when an significant weather event is not happening, there are other common use-cases for social networks:

  • Scheduled reservoir releases for recreation/boating communities.

  • Water conservation and safety education.

[Below] is a great example from the Clark County Regional Flood Control District of using Twitter to broadcast real-time conditions. The Tweet contains location metadata, a promoted hashtag to target an interested audience, and links to more information.

— Regional Flood (@RegionalFlood) September 8, 2013

So, we tweet about the severe weather and its aftermath, now what?

We also asked about significant rain events since 2008. (That year was our starting point since the first tweet was posted in 2006, and in 2008 Twitter was in its relative infancy. By 2009 there were approximately 15 million Tweets per day, while today there are approximately 400 million per day.) With this information we looked for a Twitter ‘signal’ around a single rain gauge. Part 2 presents the correlations we saw between hourly rain accumulations and hourly Twitter traffic during ten events.

These results suggest that there is an active public using Twitter to comment and share information about weather events as they happen. This provides the foundation to make Twitter a two-way communication platform during weather events. Accordingly, we also asked survey participants if there was interest in also monitoring communications coming in from the public. In general, there was interest in this along with a recognition that this piece of the puzzle was more difficult to implement. Efficiently listening to the public during extreme events requires significant effort in promoting Twitter accounts and hashtags. The [tweet to the left] is an example from the Las Vegas area, a region where it does not require a lot of rain to cause flash floods. The Clark County Regional Flood Control District detected this Tweet and retweeted within a few minutes.


Any agency or department that sets out to integrate social networks into their early-warning system will find a variety of challenges. Some of these challenges are more technical in nature, while others are more policy-related and protocol-driven.

Many weather-event monitoring systems and infrastructures are operated on an ad hoc, or as-needed, basis. When severe weather occurs, many county and city agencies deploy a temporary “emergency operations centers.” During significant events personnel are often already “maxed out” operating other data and infrastructure networks. There are also concerns over data privacy, that the public will misinterpret meteorological data, and that there is little ability to “curate” the public reactions to shared event information. Yet another challenge cited was that some agencies have policies that require special permissions to even access social networks.

There are also technical challenges when integrating social data. From automating the broadcasting of meteorological data to collecting data from social networks, there are many software and hardware details to implement. In order to identify Tweets of local interest, there are also many challenges in geo-referencing incoming data.  (Challenges made a lot easier by the new Profile Location enrichments.)

Indeed, effectively integrating social networks requires effort and dedicated resources. The most successful agencies are likely to have personnel dedicated to public outreach via social media. While the Twitter signal we detected seems to have grown naturally without much ‘coaching’ from agencies, promotion of agency accounts and hashtags is critical. The public needs to know what Twitter accounts are available for public safety communications, and hashtags enable the public to find the information they need. Effective campaigns will likely attract followers using newsletters, utility bills, Public Service Announcements, and advertising. The Clark County Regional Flood Control District even mails a newsletter to new residents highlighting local flash flood areas while promoting specific hashtags and accounts used in the region.

The Twitter response to the hydrological events we examined was substantial. Agencies need to decide how to best use social networks to augment their public outreach programs. Through education and promotion, it is likely that social media users could be encouraged to communicate important public safety observations in real time, particularly if there is an understanding that their activities are being monitored during such events. Although there are considerable challenges, there is significant potential for effective two-way communication between a mobile public and agencies charged with public safety.

Special thanks to Mike Zucosky, Manager of Field Services, OneRain, Inc., my co-presenter at the 2013 National Hydrologic Warning Council Conference.

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