Should I Stay or Should I Go

Hurricanes get all the press. Everyone wants to know their track and intensity, and if and when to evacuate. Broadcast, print and social media produce eye-catching, colorful graphics showing possible tracks a hurricane could take. And, easy-to-understand wind-strength information, such as a Category 4 storm, easily gets the attention of the public. They get it. They understand the risk, can assess their situation, and can then make informed decisions on whether to evacuate or stay put. But what about communicating and understanding storm surge risk associated with hurricanes?  This is an area that has proven to be much trickier to understand and convey to the public.

“Tsunami-like” Rise in Sea Level

Surge is deadly and one of the hardest things to communicate —NWS warning coordination meteorologist
Surge is deadly and one of the hardest things to communicate
—NWS warning coordination meteorologist

Storm surge has been defined as an abnormal rise in sea level caused by onshore winds of a severe cyclone. In 2012, Hurricane Sandy, a seemingly benign Category 1, made landfall on the east coast, and left a path of destruction in the New York tri-state area. Damage from the storm is estimated at $71.4 billion, and much of the damage was caused by a high storm surge. In New York City, for example, the storm surge with a high tide of 14 feet caused devastating damage.

More than 123 million people, or 39 percent of the nation’s population, live in shoreline counties with 446 people per square mile (versus 105 people per square mile in the nation as a whole). With many coastal areas being just 10 feet above sea level, it is critical the public understands all the risks associated with tropical and extratropical storms to their selves and property.

But how can storm surge risk be communicated to the public effectively? That has been the challenge for meteorologists, media outlets, and emergency personnel. 

Small Program Big Work

Social scientists at NCAR, in collaboration with colleagues at Florida International University and NOAA, are addressing the challenge of better communicating storm surge risk. The Hurricane Forecast Improvement Project (HFIP) is a relatively small program within NOAA focused on transitioning research to operations. What makes it unique is its support for a social science component to its program.  It has dedicated funds to improve storm surge communication, realizing it is an area that needs more research.

In a three-year period, a small group of social scientists conducted a series of studies that evaluated storm surge risk perceptions, understanding and preferred communication techniques for two categories of coastal stakeholders: experts and members of the public.  The first phase of the work was exhaustive, using in-depth interviews, focus groups, and group discussions. It was designed to assess the extent to which coastal residents understood their storm surge risk and it explored perceptions and preferences regarding new ways of communicating storm surge forecasts associated with hurricanes.

The results of this information-gathering exercise informed the design of the next phase of the project: formal surveys, focused on communication services and products, filled out by experts and laypeople.  Many of the questions in the surveys were open-ended, allowing respondents to provide important comments on topics such as the timing of communicating storm surge forecasts (how many days in advance and the time of day).

Prototype of map showing general area under a storm surge warning.
Prototype of map showing general area under a storm surge warning.

Some of the areas the scientists focused on included:

Understanding of storm surge vulnerability. Emergency managers and broadcast meteorologists were concerned about the public’s lack of knowledge and understanding of storm surge vulnerability. Among its many findings, one showed that three-fifths of the public had never heard or read an estimate of the surge vulnerability in their own area.

Preferences for a separate storm surge warning. There was strong support from both experts and the public for new storm surge warnings separate from existing hurricane wind and track warnings.

Evaluations of storm surge warning wording: The vast majority of respondents indicated strong preferences for certain wording such as the terminology “storm surge warning” over wording such as “coastal flood warning” or “extreme coastal flood warning”

Storm surge graphics conveying surge threat. A significant challenge for experts is determining the level of detail to include in storm surge information. For example, three varying degrees of colored maps were assessed by users. A multicolored map, conveying levels of storm surge in each area, was preferred over a single color or a map with a single color with varying intensity.

Prototype map showing potential storm surge area divided into four different depth categories.
Prototype map showing potential storm surge area divided into four different depth categories.

Results: Big Bang for the Buck

This project provided tremendous information to meteorologists, media and emergency personnel to help improve storm surge risk communication.  Since the results of these studies have illustrated the need for improved information on storm surge prediction, NOAA has responded. It has convened a team of experts to develop and test experimental communication products potentially useful to emergency managers, broadcast meteorologists, and the public.

NOAA, a predominantly hard science organization, had the foresight to leverage its resources and include social sciences in its research portfolio.  While a storm surge forecast begins with observations, data gathering and assimilation, and modeling that generates a forecast, it hardly ends there. What the broadcasters, emergency managers, and the general public does with that information is as equally important as the forecast itself. If the best forecast is ignored due to poor communication of it, it has failed.

This project illustrates the value of integrating the social dimensions to the physical sciences, and is a wonderful example of NCAR’s mission of producing science “in service to society.”

For more information on this research project, go to Improving storm surge risk communication: Stakeholder perspectives.