Hazard and vulnerability components upgraded

Catastrophe modelling company AIR Worldwide has released version 12.0 of its US hurricane model. According to the firm, the new version includes “extensive updates” to the hazard and vulnerability components of the model, incorporating the latest science, data and claims information from recent storms.

The model's hazard module incorporates improved knowledge of the full 4-D structure of hurricanes, including the development of the storm footprint over time, the rate of the decrease in wind speed moving away from the eye of a hurricane, and the relationship between upper-level and surface winds. The model also captures directional effects of surface friction by explicitly considering the direction of the wind at each location and incorporating the latest United States Geological Survey Land Use Land Cover data, published in 2007.

To better capture inland risk, the model domain has expanded to incorporate three new states - Illinois, Indiana, and Missouri - and now includes 29 states and the District of Columbia. In addition, the methodology for storm track and decay after landfall (or filling) now allows for more variability in the post-landfall evolution of events. While research indicates that re-intensification occurs in less than 5% of all landfalling hurricanes, the impact on inland losses can be significant. Version 12.0 captures the possibility of re-intensification of storms after landfall in the model's catalogue of simulated events.

Enhancements have also been made to the vulnerability - or damage estimation - component of the model. These improvements were enabled by AIR's continuing analysis of claims data from recent storms; new research into the evolution of building codes, building materials, construction practices and their impact on building vulnerability; recent damage survey data; engineering studies and structural calculations; and extensive literature review.

"The Version 12.0 update to the AIR US hurricane model incorporates enhancements that encompass virtually every component of the model," said Peter Dailey, assistant vice president and director of atmospheric science at AIR Worldwide. "The update sets a new standard for the industry by providing a more complete view of US hurricane risk and a significantly better method for differentiating the risk to properties based on such factors as geography, construction, occupancy, year built, and individual building characteristics."