Integrated causal-predictive machine learning models for tropical cyclone epidemiology.

Strategic preparedness reduces the adverse health impacts of hurricanes and tropical storms, referred to collectively as tropical cyclones (TCs), but its protective impact could be enhanced by a more comprehensive and rigorous characterization of TC epidemiology. To generate the insights and tools necessary for high-precision TC preparedness, we introduce a machine learning approach that standardizes estimation of historic TC health impacts, discovers common patterns and sources of heterogeneity in those health impacts, and enables identification of communities at highest health risk for future TCs. The model integrates (i) a causal inference component to quantify the immediate health impacts of recent historic TCs at high spatial resolution and (ii) a predictive component that captures how TC meteorological features and socioeconomic/demographic characteristics of impacted communities are associated with health impacts. We apply it to a rich data platform containing detailed historic TC exposure information and records of all-cause mortality and cardiovascular- and respiratory-related hospitalization among Medicare recipients. We report a high degree of heterogeneity in the acute health impacts of historic TCs, both within and across TCs, and, on average, substantial TC-attributable increases in respiratory hospitalizations. TC-sustained windspeeds are found to be the primary driver of mortality and respiratory risks.

Severe hurricanes increase recruitment and gene flow in the clonal sponge Aplysina cauliformis.

Upright branching sponges, such as Aplysina cauliformis, provide critical three-dimensional habitat for other organisms and assist in stabilizing coral reef substrata, but are highly susceptible to breakage during storms. Breakage can increase sponge fragmentation, contributing to population clonality and inbreeding. Conversely, storms could provide opportunities for new genotypes to enter populations via larval recruitment, resulting in greater genetic diversity in locations with frequent storms. The unprecedented occurrence of two Category 5 hurricanes in close succession during 2017 in the U.S. Virgin Islands (USVI) provided a unique opportunity to evaluate whether recolonization of newly available substrata on coral reefs was due to local (e.g. re-growth of remnants, fragmentation, larval recruitment) or remote (e.g. larval transport and immigration) sponge genotypes. We sampled A. cauliformis adults and juveniles from four reefs around St. Thomas and two in St. Croix (USVI). Using a 2bRAD protocol, all samples were genotyped for single-nucleotide polymorphisms (SNPs). Results showed that these major storm events favoured sponge larval recruitment but did not increase the genetic diversity of A. cauliformis populations. Recolonization of substratum post-storms via clonality was lower (15%) than expected and instead was mainly due to sexual reproduction (85%) via local larval recruitment. Storms did enhance gene flow among and within reef sites located south of St. Thomas and north of St. Croix. Therefore, populations of clonal marine species with low pelagic dispersion, such as A. cauliformis, may benefit from increased frequency and magnitude of hurricanes for the maintenance of genetic diversity and to combat inbreeding, enhancing the resilience of Caribbean sponge communities to extreme storm events.

Hurricanes enhance coral connectivity but also superspread coral diseases.

Climate change poses an existential threat to coral reefs. A warmer and more acidic ocean weakens coral ecosystems and increases the intensity of hurricanes. The wind-wave-current interactions during a hurricane deeply change the ocean circulation patterns and hence potentially affect the dispersal of coral larvae and coral disease agents. Here, we modeled the impact of major hurricane Irma (September 2017) on coral larval and stony coral tissue loss disease (SCTLD) connectivity in Florida's Coral Reef. We coupled high-resolution coastal ocean circulation and wave models to simulate the dispersal of virtual coral larvae and disease agents between thousands of reefs. While being a brief event, our results suggest the passage of hurricane Irma strongly increased the probability of long-distance exchanges while reducing larval supply. It created new connections that could promote coral resilience but also probably accelerated the spread of SCTLD by about a month. As they become more intense, hurricanes' double-edged effect will become increasingly pronounced, contributing to increased variability in transport patterns and an accelerated rate of change within coral reef ecosystems.

Hurricanes pose a substantial risk to New England forest carbon stocks.

Nature-based climate solutions (NCS) are championed as a primary tool to mitigate climate change, especially in forested regions capable of storing and sequestering vast amounts of carbon. New England is one of the most heavily forested regions in the United States (>75% forested by land area), and forest carbon is a significant component of climate mitigation policies. Large infrequent disturbances, such as hurricanes, are a major source of uncertainty and risk for policies relying on forest carbon for climate mitigation, especially as climate change is projected to alter the intensity and extent of hurricanes. To date, most research into disturbance impacts on forest carbon stocks has focused on fire. Here, we show that a single hurricane in the region can down between 121 and 250 MMTCO2e or 4.6%-9.4% of the total aboveground forest carbon, much greater than the carbon sequestered annually by New England's forests (16 MMTCO2e year-1). However, emissions from hurricanes are not instantaneous; it takes approximately 19 years for downed carbon to become a net emission and 100 years for 90% of the downed carbon to be emitted. Reconstructing hurricanes with the HURRECON and EXPOS models across a range of historical and projected wind speeds, we find that an 8% and 16% increase in hurricane wind speeds leads to a 10.7- and 24.8-fold increase in the extent of high-severity damaged areas (widespread tree mortality). Increased wind speed also leads to unprecedented geographical shifts in damage, both inland and northward, into heavily forested regions traditionally less affected by hurricanes. Given that a single hurricane can emit the equivalent of 10+ years of carbon sequestered by forests in New England, the status of these forests as a durable carbon sink is uncertain. Understanding the risks to forest carbon stocks from disturbances is necessary for decision-makers relying on forests as a NCS.

Exposure of protected areas in Central America to extreme weather events.

Central America and the Caribbean are regularly battered by megadroughts, heavy rainfall, heat waves, and tropical cyclones. Although 21st-century climate change is expected to increase the frequency, intensity, and duration of these extreme weather events (EWEs), their incidence in regional protected areas (PAs) remains poorly explored. We examined historical and projected EWEs across the region based on 32 metrics that describe distinct dimensions (i.e., intensity, duration, and frequency) of heat waves, cyclones, droughts, and rainfall and compared trends in PAs with trends in unprotected lands. From the early 21st century onward, exposure to EWEs increased across the region, and PAs were predicted to be more exposed to climate extremes than unprotected areas (as shown by autoregressive model coefficients at p < 0.05 significance level). This was particularly true for heat waves, which were projected to have a significantly higher average (tested by Wilcoxon tests at p < 0.01) intensity and duration, and tropical cyclones, which affected PAs more severely in carbon-intensive scenarios. PAs were also predicted to be significantly less exposed to droughts and heavy rainfall than unprotected areas (tested by Wilcoxon tests at p < 0.01). However, droughts that could threaten connectivity between PAs are increasingly common in this region. We estimated that approximately 65% of the study area will experience at least one drought episode that is more intense and longer lasting than previous droughts. Collectively, our results highlight that new conservation strategies adapted to threats associated with EWEs need to be tailored and implemented promptly. Unless urgent action is taken, significant damage may be inflicted on the unique biodiversity of the region.

Ciclones, olas de calor, sequías y lluvias intensas son eventos comunes en Centroamérica y el Caribe, cuya frecuencia, intensidad y duración se espera aumente durante el siglo XXI a causa del cambio climático. Sin embargo, en la actualidad, se desconoce cuál será la incidencia de estos eventos meteorológicos extremos (EME) dentro de las áreas protegidas. En este estudio examinamos la exposición histórica y futura a los extremos climáticos y comparamos el grado de exposición dentro y fuera de las áreas protegidas de toda la región por medio de 32 métricas que describen distintas dimensiones (intensidad, duración y frecuencia) de las olas de calor, los ciclones, las sequías y las precipitaciones. Los resultados indican que a medida que aumente el número de EME, las áreas protegidas estarán más expuestas a los extremos climáticos que las áreas no protegidas. Esto es especialmente cierto en el caso de las olas de calor, que, según las proyecciones, tendrán una intensidad y una duración medias significativamente mayores, y de los ciclones tropicales, que afectarán más gravemente a las zonas protegidas en los escenarios intensivos en carbono. Nuestros resultados también indican que las zonas protegidas estarán significativamente menos expuestas a sequías o lluvias torrenciales que las zonas no protegidas. Sin embargo, las sequías que podrían amenazar la conectividad entre áreas protegidas son cada vez más frecuentes en esta región. Se estima que aproximadamente el 65% del área de estudio experimentará al menos un episodio de sequía más intenso y duradero que las sequías anteriores. En conjunto, nuestros resultados ponen de relieve la necesidad de diseñar y aplicar con prontitud nuevas estrategias de conservación adaptadas a las amenazas asociadas a los EWE. A menos que se tomen medidas urgentes, la biodiversidad única de la región podría sufrir daños considerables.

Disaster solidarity and survivor ethics: a case study of Hurricane María in Puerto Rico.

Liminal periods of disaster solidarity in the aftermath of disaster are a common experience of many survivors. These periods have a specifically ethical component in that people spontaneously engage in collective, altruistic action and magnanimously expand their ethical focus beyond normative social distinctions and hierarchies. Inevitably, however, such solidarity seems to wane, and people return to pre-disaster patterns of interaction. Nevertheless, some individuals move beyond opportune acts of assistance to more extensive reorganisations of their lives during the recovery period and reshape their ethical commitments in new and durable directions. These individuals help make visible marginalised 'others' and draw collaborators to share new ethical visions. Based on observational and interview data collected after Hurricane María (2017) in a mountainous Puerto Rican municipality and employing the framework of virtue ethics, this paper examines the differential effects of disaster solidarity on survivors' ethical responses and the different contributions these make to society.

Hurricanes affect diversification among individual life courses of a primate population.

Extreme climatic events may influence individual-level variability in phenotypes, survival and reproduction, and thereby drive the pace of evolution. Climate models predict increases in the frequency of intense hurricanes, but no study has measured their impact on individual life courses within animal populations. We used 45 years of demographic data of rhesus macaques to quantify the influence of major hurricanes on reproductive life courses using multiple metrics of dynamic heterogeneity accounting for life course variability and life-history trait variances. To reduce intraspecific competition, individuals may explore new reproductive stages during years of major hurricanes, resulting in higher temporal variation in reproductive trajectories. Alternatively, individuals may opt for a single optimal life-history strategy due to trade-offs between survival and reproduction. Our results show that heterogeneity in reproductive life courses increased by 4% during years of major hurricanes, despite a 2% reduction in the asymptotic growth rate due to an average decrease in mean fertility and survival by that is, shortened life courses and reduced reproductive output. In agreement with this, the population is expected to achieve stable population dynamics faster after being perturbed by a hurricane ( ρ = 1.512 ; 95% CI: 1.488, 1.538), relative to ordinary years ρ = 1.482 ; 1.475 , 1.490 . Our work suggests that natural disasters force individuals into new demographic roles to potentially reduce competition during unfavourable environments where mean reproduction and survival are compromised. Variance in lifetime reproductive success and longevity are differently affected by hurricanes, and such variability is mostly driven by survival.

Trends in carbon monoxide poisoning deaths in high frequency hurricane states from 2014-19: the need for prevention intervention strategies.

INTRODUCTION: Hurricanes often result in power outages, which increase generator usage and carbon monoxide (CO) deaths. We aim to identify states with the highest frequency of hurricanes and evaluate the number of unintentional CO poisoning deaths by region, age, race and metropolitan distribution. METHODS: The number of hurricanes was determined using the FEMA database, and the number of unintentional CO poisoning deaths was determined using the CDC WONDER database from 2014-19. Hurricane-associated consumer outages were obtained from the Department of Energy. RESULTS: The number of unintentional CO poisoning deaths was as follows: Florida, South Carolina, North Carolina, Georgia and Alabama. Adults displayed a significantly higher number of unintentional CO poisoning deaths than pediatrics (P < 0.001). The total number of unintentional CO poisoning deaths was highest in the White population (P < 0.001); however, unintentional CO poisoning death rates were nearly two times higher among Black population in adults (0.5 versus 0.3) and pediatrics (0.2 versus 0.1). Medium metropolitan areas exhibited significantly more unintentional CO poisoning deaths (P < 0.001). CONCLUSIONS: Hurricanes and unintentional CO poisoning deaths were most common in Florida. Death rates were higher among Black individuals. Medium metropolitan areas displayed significantly more unintentional CO poisoning deaths than all other areas.

Hurricane Michael and Adverse Social and Mental Health Risk Factors.

OBJECTIVES: To assess changes in mental health and social risk factors in pregnant women in counties affected by Hurricane Michael (October 2018). METHODS: Data from the Universal Perinatal Risk Screen (UPRS) and vital statistics for the state of Florida were obtained. Prenatal risk factors (unplanned pregnancy, mental health services, high stress, use of tobacco or alcohol, young children at home or with special needs, trouble paying bills) were compared in the year before and year after Hurricane Michael in affected counties (n = 18,887). Log-Poisson regression with robust variance was used for binary outcomes, adjusting for maternal age, race, BMI, and education. RESULTS: A smaller proportion of pregnant women were screened in the months after the hurricane. No changes were seen in overall scores. The proportion referred was lower in the 1 month after Michael compared to that in 1 month before Michael (RR 0.78, 95% CI = 0.71, 0.86), but greater in the year after (RR = 1.07, 95% CI: 1.04, 1.10). Most individual risk factors on the screener did not change significantly, except having an illness that required ongoing medical care was less common in the short term (3 months after vs. 3 months before: aRR = 0.76, 95% CI: 0.66, 0.87), and more common in the longer term (1 year after vs. 1 year before, aRR = 1.09, 95% CI: 1.02, 1.18). Birth certificate data suggested smoking during pregnancy was higher among women who experienced Michael during their pregnancies (aRR = 1.15, 95% CI: 1.01, 1.32). DISCUSSION: Perinatal screening and referral declined in the short-term aftermath of Hurricane Michael.

Mangroves protect coastal economic activity from hurricanes.

This paper evaluates whether mangroves can mitigate the impact of hurricanes on economic activity. The paper assembles a regionwide panel dataset that measures local economic activity using nightlights, potential hurricane damages using a detailed wind field model, and mangrove protection by mapping the width of mangrove forests on the path to the coast. The results show that hurricanes have negative short-run effects on economic activity, with losses likely concentrated in coastal lowlands that are exposed to both wind and storm surge hazards. In these coastal lowlands, the estimates show that nightlights decrease by up to 24% in areas that are unprotected by mangroves. By comparison, the impact of the hurricanes observed in the sample is fully mitigated in areas protected by mangrove belts of 1 km or more.

Rent affordability after hurricanes: Longitudinal evidence from US coastal states.

Climate change is expected to increase the frequency and intensity of natural hazards such as hurricanes. With a severe shortage of affordable housing in the United States, renters may be uniquely vulnerable to disaster-related housing disruptions due to increased hazard exposure, physical vulnerability of structures, and socioeconomic disadvantage. In this work, we construct a panel dataset consisting of housing, socioeconomic, and hurricane disaster data from counties in 19 states across the East and Gulf Coasts of the United States from 2009 to 2018 to investigate how the frequency and intensity of a hurricane correspond to changes in median rent and housing affordability (the interaction between rent prices and income) over time. Using a two-stage least square random-effects regression model, we find that more intense prior-year hurricanes correspond to increases in median rents via declines in housing availability. The relationship between hurricanes and rent affordability is more complex, though the occurrence of a hurricane in a given year or the previous year reduces affordable rental housing, especially for counties with higher percentages of renters and people of color. Our results highlight the multiple challenges that renters are likely to face following a hurricane, and we emphasize that disaster recovery in short- and medium-term should focus on providing safe, stable, and affordable rental housing assistance.

Hurricanes and Mortality among Patients Receiving Dialysis.

BACKGROUND: Hurricanes are severe weather events that can disrupt power, water, and transportation systems. These disruptions may be deadly for patients requiring maintenance dialysis. We hypothesized that the mortality risk among patients requiring maintenance dialysis would be increased in the 30 days after a hurricane. METHODS: Patients registered as requiring maintenance dialysis in the United States Renal Data System who initiated treatment between January 1, 1997 and December 31, 2017 in one of 108 hurricane-afflicted counties were followed from dialysis initiation until transplantation, dialysis discontinuation, a move to a nonafflicted county, or death. Hurricane exposure was determined as a tropical cyclone event with peak local wind speeds ≥64 knots in the county of a patient's residence. The risk of death after the hurricane was estimated using time-varying Cox proportional hazards models. RESULTS: The median age of the 187,388 patients was 65 years (IQR, 53-75) and 43.7% were female. There were 27 hurricanes and 105,398 deaths in 529,339 person-years of follow-up on dialysis. In total, 29,849 patients were exposed to at least one hurricane. Hurricane exposure was associated with a significantly higher mortality after adjusting for demographic and socioeconomic covariates (hazard ratio, 1.13; 95% confidence interval, 1.05 to 1.22). The association persisted when adjusting for seasonality. CONCLUSIONS: Patients requiring maintenance dialysis have a higher mortality risk in the 30 days after a hurricane.

Longitudinal assessment of mental health after a flood: roles of social support, hope, recovery stressors, and prior lifetime trauma.

OBJECTIVES: Severe weather events have mental health consequences for survivors that may change over time. We assessed post-flood mental health longitudinally in three groups of mostly middle-aged and older adults who varied in current and prior severe weather experiences. METHOD: Predictors of central interest were age, perceived social support, state hope (including agency and pathways), recovery stressors, and prior lifetime trauma. Criterion variables included symptoms of depression, post-traumatic stress disorder (PTSD), and worry. RESULTS: Analyses of variance yielded significant Disaster Exposure Group x Wave interactions for depression and PTSD symptoms. Those with flooded homes and properties had elevated symptoms at Wave 1 which were reduced at Wave 2. Older age was associated with fewer symptoms of depression, PTSD, and worry. Recovery stressors and lifetime trauma predicted more PTSD symptoms. Greater agency predicted less PTSD and depression symptoms, whereas pathways predicted less worry. CONCLUSION: These data show that mental health symptoms may decrease over time for those directly impacted by severe flooding. State hope appears to contribute to better mental health after exposure to a devastating flood. Implications for understanding the dynamic relationships among risk variables and positive factors that promote post-disaster mental health in the years after a flood are considered.

Official sources, news outlets, or search engines? Rumour validation on social media during Hurricanes Harvey and Irma.

This study, based on data collected from a representative sample of adults in the United States, explores the social cognitive variables that motivated Americans to validate rumours on social media about Hurricanes Harvey and Irma, both of which struck in August/September 2017. The results indicate that risk perception and negative emotions are positively related to systematic processing of relevant risk information, and that systematic processing is significantly related to rumour validation through search engines such as Google. In contrast, trust in information about the hurricane is significantly related to validation through official sources, such as FEMA (Federal Emergency Management Agency), and major news outlets such as The New York Times. Trust in information is also significantly related to systematic processing of risk information. The findings of this study suggest that ordinary citizens may be motivated to validate rumours on social media, which is an increasingly important issue in contemporary societies.

Fear Language in a Warning Is Beneficial to Risk Perception in Lower-Risk Situations.

OBJECTIVE: The goal was to examine the effectiveness of fear language in the protective action recommendation of an emergency warning, which instructs people how to prepare and stay safe. BACKGROUND: Past work is limited because it has focused on describing the severity of the weather crisis, not improving the recommendation. Likewise, other research has examined fear appeals that overemphasize death, which leads to poor risk perceptions. METHOD: In Experiment 1, the presence of fear language and second-person personal pronouns (i.e., "you") in a recommendation was manipulated. Experiment 2 examined how fear language and a hurricane changing in intensity influenced risk perceptions across three decision points. RESULTS: Experiment 1 suggested that fear language was more influential than a pronoun on risk perceptions. Experiment 2 suggested that fear language in a protective action recommendation was most impactful in the case of a hurricane decreasing in intensity. CONCLUSION: Protective action recommendations with fear language influence risk perceptions and behaviors. The magnitude of this influence is dependent on how people have categorized the hurricane (i.e., low vs. high risk). APPLICATION: These results demonstrate that fear appeals in hurricane warnings can be useful, especially in cases when a low to medium risk event is still extremely dangerous. Likewise, these results demonstrate a need for caution, as fear appeals are not a "one size-fits-all" approach to increasing risk perceptions and should be used thoughtfully. Recommendations of when to use fear appeals in protective action recommendations are provided based on the present data.

Can hurricanes drive green innovations?

We propose that natural disasters (specifically hurricanes) encourage the development of green innovations in small island developing states (SIDS). Using a novel and unique dataset of hurricane instances and green innovation activities in SIDS, we find that hurricanes follow a U-shaped relationship with green innovations. This suggests that while initially hurricanes negatively impact green innovations, as firms experience more hurricanes, this will trigger the development of green innovations. Our results also reveal that present and future government regulations act as antecedents to green innovation, however government incentives (i.e., grants, subsidies, and financial incentives) are not found to impact on firms' willingness to develop green innovations. Furthermore, customer/market demand and industry codes of environmental good practice (societal influences) are found to trigger green innovation activities in SIDS firms. Finally, we find that hurricanes have no significant effect on other 'traditional' types of innovation. Our study deepens understanding of the underexplored nexus between natural disaster events and green innovations and has implication for optimizing policy design ('command and control' regulations vs 'market-based' incentives) for green innovations.

Disruptions in Oncology Care Confronted by Patients with Gynecologic Cancer Following Hurricanes Irma and Maria in Puerto Rico.

BACKGROUND: In September 2017, hurricanes Irma and Maria affected Puerto Rico (PR) and the US Virgin Islands (USVI), causing major disruptions in basic services and health care. This study documented the stressors and experiences of patients with gynecologic cancer receiving oncology care in PR following these hurricanes. METHODS: We conducted 4 focus groups (December 2018-April 2019) among women aged ≥21 years from PR who were diagnosed with gynecological cancer between September 2016 and September 2018 (n = 24). Using the same eligibility criteria, we also interviewed patients from the USVI (n = 2) who were treated in PR. We also conducted key-informant interviews with oncology care providers and administrators (n = 23) serving gynecologic cancer patients in PR. Discussions were audio-recorded, transcribed verbatim, and coded to identify emergent themes using a constant comparison method. RESULTS: Analyses of focus group discussions and interviews allowed us to identify the following emergent themes: 1) disruptions in oncology care were common; 2) communication between oncology providers and patients was challenging before and after the hurricanes hit; 3) patient resilience was key to resume care; and 4) local communities provided much-needed social support and resources. CONCLUSIONS: This study provides firsthand information about the disruptions in oncology care experienced by and the resiliency of women with gynecologic cancer following hurricanes Irma and Maria. Our findings underscore the need to incorporate oncology care in the preparedness and response plans of communities, health systems, and government agencies to maintain adequate care for cancer patients during and after disasters such as hurricanes.

No evidence of predicted phenotypic changes after hurricane disturbance in a shade-specialist Caribbean anole.

Extreme climatic events (ECEs) such as hurricanes have been hypothesized to be a major driving force of natural selection. Recent studies argue that, following strong hurricane disturbance, Anolis lizards in the Caribbean undergo selection for traits such as longer forelimbs or smaller body sizes that improve their clinging ability to their substrates increasing their chances of surviving hurricane wind gusts. Some authors challenge the generalization of this hypothesis arguing that other mechanisms may explain these phenotypic changes or that they may not necessarily be generalizable across systems. To address this issue, we compared body size and relative forelimb length of Anolis gundlachi, a trunk-ground anole living in closed-canopy forests in Puerto Rico, before, four months after, and 15 months after Hurricanes Irma and Maria in 2017. Overall, our results show no clear evidence of a temporal decrease in body size or increase forelimb length (relative to body size) challenging the generalizability of the clinging ability hypothesis. Understanding how animals adapt to ECE is an emerging field. Still, we are quickly learning that this process is complex and nuanced.

Throwing caution to the wind: How hurricanes affect COVID-19 spread.

This study exploits the pathway of Hurricane Laura to assess its impact on the spread of COVID-19. Using US hospital data on confirmed and suspected adult COVID-19 cases, we find average daily cases per week rose by more than 12% primarily in tropical storm-affected counties in subsequent weeks. We suspect the key mechanisms involve constraints on social distancing for two reasons. First, there is significant evidence of storm-induced mobility. Second, lower income areas endured higher growth in hospital cases during the post-hurricane period. These findings provide crucial insights for policy-makers when designing natural disaster protocols to adjust for potential respiratory viral illnesses.

Media exposure, threat processing, and mitigation behaviors in Gulf Coast residents facing the co-occurring threats of COVID-19 and hurricanes.

The 2020 hurricane season threatened millions of Americans concurrently grappling with COVID-19. Processes guiding individual-level mitigation for these conceptually distinct threats, one novel and chronic (COVID-19), the other familiar and episodic (hurricanes), are unknown. Theories of health protective behaviors suggest that inputs from external stimuli (e.g., traditional and social media) lead to threat processing, including perceived efficacy (self- and response) and perceived threat (susceptibility and severity), guiding mitigation behavior. We surveyed a representative sample of Florida and Texas residents (N = 1846) between April 14, 2020 and April 27, 2020; many had previous hurricane exposure; all were previously assessed between September 8, 2017 and September 11, 2017. Using preregistered analyses, two generalized structural equation models tested direct and indirect effects of media exposure (traditional media, social media) on self-reported (1) COVID-19 mitigation (handwashing, mask-wearing, social distancing) and (2) hurricane mitigation (preparation behaviors), as mediated through perceived efficacy (self- and response) and perceived threat (susceptibility and severity). Self-efficacy and response efficacy were associated with social distancing (p = .002), handwashing, mask-wearing, and hurricane preparation (ps < 0.001). Perceived susceptibility was positively associated with social distancing (p = 0.017) and hurricane preparation (p < 0.001). Perceived severity was positively associated with social distancing (p < 0.001). Traditional media exhibited indirect effects on COVID-19 mitigation through increased response efficacy (ps < 0.05), and to a lesser extent self-efficacy (p < 0.05), and on hurricane preparation through increased self-efficacy and response efficacy and perceived susceptibility (ps < 0.05). Social media did not exhibit indirect effects on COVID-19 or hurricane mitigation. Communications targeting efficacy and susceptibility may encourage mitigation behavior; research should explore how social media campaigns can more effectively target threat processing, guiding protective actions.