JBA urges flood‑hurricane modelling

JBA Risk Management said on May 13 that insurers, reinsurers and infrastructure planners should assess hurricane wind, storm surge and inland flooding together rather than as separate hazards. The company made the case in an article by Principal Analyst and Catastrophe Model Specialist Dr. David Cross, which said heavier rainfall and more destructive flooding are increasingly arriving with tropical cyclones. JBA said it has linked its inland flood model with Applied Research Associates’ HurLoss hurricane wind and surge model for U.S. risk analysis. The company said the combined approach is aimed at giving clients a single framework for correlated hurricane losses across wind, surge and inland flood. ### Why is JBA pushing a joint approach now? Dr. David Cross wrote that rising ocean temperatures can provide more energy for hurricanes, while warmer air can hold more moisture and raise the potential for extreme rainfall and flooding. He said those conditions are producing more “compound” events in which multiple hazards arrive together and interact. JBA pointed to the July 2025 Texas flooding associated with Tropical Storm Barry as an example of tropical moisture moving inland and producing severe impacts away from the coast. (insurance-canada.ca) Cross also cited hurricanes Harvey and Florence as examples of slower-moving, rain-laden storms that, in his words, make joint assessment essential for loss estimation. ### What does the firm say separate models miss? (insurance-canada.ca) JBA said flood and hurricanes are often modelled separately because that can produce strong results for each peril on its own and matches how many insurers buy vendor models. Cross said the problem comes when firms try to estimate total tail losses afterward by making assumptions about how the hazards interact. JBA’s flood materials say its models already distinguish among fluvial, pluvial and coastal flooding, and the company’s broader product range includes combined wind-and-flood offerings. (insurance-canada.ca) In the May 13 article, Cross said treating those hazards in isolation can understate or misstate losses when the drivers are correlated in the same event. A long-standing Defra and Environment Agency guide on joint probability methods makes a similar technical point: flood risk is rarely driven by one variable alone and more often reflects combinations of rainfall, river flow, sea level, surge or waves. (insurance-canada.ca) That document predates JBA’s announcement by two decades, but it shows the underlying engineering issue is established even as vendors update commercial models. ### Where do the interactions show up in real assets? Insurance-Canada’s May 13 posting of Cross’s article said compound loadings can include situations such as tide-locked outfalls during intense rainfall, when coastal conditions prevent drainage systems from discharging efficiently. That can raise inland water levels even if a project has been designed around a single hazard assumption. (assets.publishing.service.gov.uk) JBA said those interactions matter for coastal infrastructure and urban drainage as well as insurance portfolios. The company’s public materials say it provides flood-defence design and single-site assessments in addition to portfolio analytics, which places the modelling argument in both engineering and underwriting work. ### What exactly are JBA and ARA combining? Applied Research Associates says HurLoss is its hurricane catastrophe model for property insurers, reinsurers, brokers and insurance-linked securities managers, covering the North Atlantic basin and including wind and surge capabilities. (insurance-canada.ca) JBA said its contribution is the inland flood side of the analysis, with global flood models and high-resolution maps that cover river, surface-water and coastal flooding. (jbarisk.com) The May 13 article said clients can continue using the models they already know while drawing deeper insight when the outputs are used together. Cross wrote that the framework is intended for the United States, where hurricane wind, storm surge and inland flood can all hit the same insured locations in one event. ### Who is the audience for the warning? JBA named insurers, reinsurers and risk managers as the immediate users of the combined framework. (ara.com) The company also said the same logic applies to coastal and urban drainage projects, where designers and supervisors should test combined loading and failure pathways rather than assume each hazard arrives alone. JBA’s website says it offers catastrophe models, flood maps, consultancy and climate-change scenarios to insurers, lenders, investors and property-sector clients worldwide. (insurance-canada.ca) Applied Research Associates says HurLoss has been used by hurricane-risk market participants since 1998. May 13 is the latest dated public statement located for this push, and the combined JBA-ARA framework is already being presented as available for U.S. hurricane wind, surge and inland flood analysis. (insurance-canada.ca) Clients can find the details in Cross’s article carried by Insurance-Canada and in the companies’ product pages for JBA flood modelling and ARA’s HurLoss platform. (jbarisk.com)