Extreme Weather Resulting in Health Outcomes: Touchstone Events Communication

Background: The Florida Department of Health Building Resilience Against Climate Effects (BRACE) Program is working to improve the ability of the public health sector to respond to health effects of weather variability. The BRACE Program is focused on the following hazards geographically focusing on the entire state of Florida: hurricanes, wildland fires, extreme temperatures, flooding (extreme precipitation), drought, and sea level rise. It is supported by the Centers for Disease Control and Prevention Climate-Ready States and Cities Initiative.

When trying to communicate information, it is often beneficial to use examples. The objective of this project is to create a bank of historical extreme weather and health “touchstone” events for use in communicating and illustrating scenarios developed by the BRACE program. Touchstone event/year summaries will include the type of event, meteorology/climatology synopses, and anecdotal reports, including documented health outcomes, if possible.

Methods: To systematically identify years with extreme weather outcomes, we used the Florida-specific Climate Extremes Index (FL-CEI), developed by climatologists in Florida and North Carolina. The FL-CEI is modeled on the National Climatic Data Center's U.S. CEI, and similarly measures the fraction of a geographic area experiencing weather extremes in one or more components. A 2013 American Meteorological Society presentation by M. Griffin introduced, “Developing a Localized Climate Extremes Index for Individual State”, (Wootten et al., 2013). Climate data of the FL-CEI showing the greatest year-to-year variations, such as changes in the mean, higher amplitude swings, and shifting distribution tails, aided in identifying years of study.

The FL-CEI consists of annual results available from 1955 to 2012, including hurricane, severe weather (thunderstorms, hail, tornadoes), winter weather, and standardized climate extreme (temperature, precipitation) components. The components of the FL-CEI have been systematically broken down so each climate and weather parameter can be analyzed, while also including an overall value of intensity per year. The FL-CEI enabled us to analytically identify the years of interest pertaining to hurricanes, extreme heat, extreme cold, flooding (extreme precipitation), and drought.

The hurricane parameters account for storm intensity (wind speed, duration) and quantity of tropical cyclones which directly (e.g. direct landfalls) or indirectly (e.g. passing nearby offshore) effect Florida. These parameters have been weighted in order to provide an outcome that is consistent with the climatology of Florida. The standardized climate portion of the FL-CEI addresses both temperature minimums and maximums by breaking these extremes down into the exposure of temperatures above and below normal. The extreme heat hazard is based on temperature rather than heat index, because available heat index data is inconsistent with the geographic or temporal scope of this project. Extreme cold is also based on temperature. Florida is home to a large agricultural industry and vulnerable populations, and winter air masses have the potential of supplying sub-freezing temperatures for lengthy periods.

Two parameters of rainfall are used for the flooding (heavy precipitation) hazard: extreme one-day precipitation events and number of days with precipitation. These two classifications allowed for capture of flash flooding episodes as well as lengthy rainfall periods. It is imperative to note we were only interested in cases not associated with tropical cyclones.

The drought component of the FL-CEI uses the Palmer Drought Severity Index (PSDI) for its moisture comprehension abilities (i.e., precipitation, runoff, soil moisture), limited lag in detecting emerging events, and capacity for quantifying the intensity of short- to long-term droughts.

For reference, see “A Revised U.S. Climate Extremes Index” (Gleason et al., 2008).

For the wildland fire and sea level rise (using astronomical high tides as a proxy) hazards, other available public datasets (i.e., National Oceanic and Atmospheric Administration (NOAA), National Climatic Data Center) were used.

Meteorological/climatological synopses include a description of weather and climate pertaining to the hazard event/year. Watches and warnings issued by the National Weather Service, as well as other official environmental services, are included when available. Scale relationships and definitions of standards in weather phenomena are included for reference (i.e., total acres burned were similar to the entire state of Delaware).

The anecdotal reports of the touchstone event/year summaries were obtained from several sources. U.S. Storm Data and Unusual Phenomena records were gathered from the Florida Climate Center, while newspaper articles were acquired through The Florida State University libraries and online databases. Internet queries also lead us to official government synopses by the United States Geological Survey (USGS), Federal Emergency Management Agency (FEMA), Florida Forest Service, etc. These avenues also provided consistency in obtaining possible health outcomes. Results: The FL-CEI proved useful and enabled us to analytically identify the years of interest for: hurricanes, extreme temperatures, flooding (extreme precipitation), and drought. Online reports and information from the NOAA, Florida Forest Service, and FEMA provided useful information in analyzing the wildland fire hazard. The Tides and Currents tool found on the NOAA website supplied sea level measurements and information. We found the following years to be optimal in representing historical extreme weather and health “touchstone” events in Florida: hurricanes, 1992 (event) and 2004 (year); extreme heat, 1998 (year); extreme cold, 1989 (event); flooding, 1990 (year); drought, 1954-1956 (years) and 2006-2008 (years); wildland fire, 1998 (event); and sea level rise, 2012 (year).

Advancements on many fronts, such as agricultural practices, weather forecasting techniques, health care, and infrastructural progression have altered the repercussions of natural disasters, and an example from an earlier time period has the possibility to be overlooked. We acknowledge these past events but have elected to study more recent events, for the objective of this project is to recall memorable occurrences.

Conclusion: The resulting touchstone summaries will be used by the Florida BRACE Program for communicating with the public and stakeholders. This project can be shared and used as a model by other jurisdictions planning climate and health adaptation interventions primarily, when communicating and illustrating scenarios developed for health implications based on weather variability. We also anticipate that this will be a platform/methodology for others to utilize in relaying memorable events. Work in Florida will be ongoing to expand the number of touchstone event summaries and to incorporate other climate and health hazards.