AIR Worldwide Releases Third-Generation NWP-Based European Extratropical Cyclone Model

BOSTON, May 15, 2006 — AIR Worldwide Corporation (AIR) released its third-generation numerical weather prediction-based (NWP) European Extratropical Cyclone Model today. The update further advances AIR's industry-leading application of NWP technology to enable insurers to better estimate potential losses from extreme windstorms in Europe through a new approach based on the principle of Available Potential Energy (APE).

"AIR's European Extratropical Cyclone Model is highly regarded within the European insurance community for its innovative use of numerical weather prediction technology," said Erik Rüttener, head of Global Natural Hazards at Swiss-based reinsurer Converium. "AIR's enhancements will enable Converium to further deepen the understanding of our extratropical cyclone risk in Europe."

"AIR has invested more than 10 years of research and development integrating NWP technology into its catastrophe models," said Yörn Tatge, managing director of AIR Worldwide GmbH. "The latest model release leverages advancements by AIR meteorologists in the application of NWP technology to windstorm models. The new techniques have been peer-reviewed by Dr. Robert Fovell of UCLA, a preeminent atmospheric scientist and a recognized expert in NWP technology."

AIR meteorologists developed an original application of Available Potential Energy, a well-known meteorological principle depicting the build-up of midlatitude energy. The relationship between APE and storm intensity was used to refine the distribution of winds within each simulated event while maintaining the overall integrity of each extratropical system. The result is a stochastic catalog of potential storms with more realistic wind footprints.

"AIR's physical-stochastic approach combines NWP and stochastic techniques in a new way," said Dr. Fovell. "The NWP component accurately constrains the stochastic while the stochastic component amply extends the physical. This unique approach results in a highly realistic view of the risk from extratropical cyclones."

The model update also includes the addition of Windstorm Erwin to the historical event set. In January 2005, Erwin caused damaging winds in several Northern European countries. Denmark was hit particularly hard, partly as a result of the so-called "sting jet" phenomenon, which accelerates strong winds aloft down to the surface in the presence of convective (thunderstorm) cells.

"Extratropical cyclones are asymmetric storm systems that produce a variety of complex atmospheric phenomena, including sting jets," continued Tatge. "Using a three-dimensional NWP-based simulation of the storm, the AIR model successfully captured the impact of the extreme surface winds caused by Erwin's sting jet. This further validates the realistic and accurate view of extratropical cyclone risk provided by the AIR model."

AIR's third-generation European Extratropical Cyclone Model is available in version 8.0 of CLASIC/2™ and CATRADER® , AIR's catastrophe risk management systems.

About AIR Worldwide Corporation
AIR Worldwide Corporation (AIR) is a leading risk modeling company helping clients manage the financial impact of catastrophes and weather. Utilizing the latest science and technology, AIR models natural catastrophes in more than 40 countries and the risk from terrorism in the United States. Other areas of expertise include site-specific seismic engineering analysis, catastrophe bonds and property replacement cost valuation. A member of the ISO family of companies, AIR was founded in 1987 to provide its insurance, reinsurance, corporate and government clients a complete line of risk modeling software and consulting services that produce consistent and reliable results. Headquartered in Boston, AIR has additional offices in North America, Europe and Asia. For more information, please visit

Release: Immediate

Giuseppe Barone / Erica Helton
MWW Group (for ISO)
201-507-9500 /

Michael Gannon (AIR Worldwide)

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