AIR Worldwide Unveils 2003 European Extratropical Cyclone Model

AIR Worldwide Corporation (AIR) announced the release of its 2003 European extratropical cyclone model, which is used by insurers and reinsurers to price contracts and manage risk from these windstorms.

The model incorporates the latest advances in AIR’s numerical weather prediction (NWP) capabilities and updated damage functions based on actual loss data from recent storms. The model also updates AIR’s property value database for Europe. AIR’s expanded use of NWP technology captures a much higher degree of resolution than previously possible. The result is increased realism in storm evolution and increased accuracy in loss estimates.

“Mid-latitude storms are much more complex than their tropical cyclone counterparts. For example, winds in a mid-latitude storm do not monotonically increase as you approach the storm’s center. Rather, the strongest winds are tied to a complex interaction of fine scale features, or substructures, embedded within the storm,” said Dr. Stephane Goyette of the Institute of Geophysics at the University of Fribourg, Switzerland. “To effectively model these storms, it is necessary to simulate these individual substructures at an appropriate resolution. This can only be accomplished by physical modeling of the atmosphere, such as through the application of NWP technology.”

AIR first introduced NWP technology into its European windstorm model in 2000. NWP incorporates comprehensive environmental physics and sophisticated numerical techniques to simulate a full range of atmospheric phenomena. AIR’s enhanced implementation of NWP effectively captures fronts, gravity waves, thunderstorm downdrafts and other substructures embedded in these storms.

“NWP technology is used today by the major meteorological agencies around the world, including the Met Office, Meteo-France, Der Deutscher Wetterdienst, and the European Centre for Medium-Range Weather Forecasts (ECMWF),” said Neil Wiseman, managing director of AIR Limited in London. “Its adoption has required a considerable investment both in meteorological expertise and in computing resources. Thus far, AIR is the only modelling firm that has moved away from the parameterised approach to modelling European windstorms.”

The 2003 release also incorporates new research from AIR’s wind engineering group. Based on loss data from recent storms AIR has reassessed the relative building vulnerability between countries by considering country-specific conditions such as climate, engineering practice, regional building features and socio-economic factors. Additional damage functions have been introduced for country-specific construction and occupancy types.