Historical Storm Footprint Analysis System

The AEF Hurricane modeling system has the capability of reproducing historical storms that our clients select for detailed investigation.

In one example, a client requested a reconstruction of Super Typhoon Mirielle, a powerful storm that struck Japan in 1991 and for which good-quality observational data was limited.

The reconstruction incorporated best track data from the U.S. Joint Typhoon Warning Center, providing storm position and maximum surface wind every 6 hours, high-resolution topography and landuse data, and surface meteorological observations collected during the storm.

In order to utilize these data and to simulate the landfall in Japan with the highest possible degree of realism, a special initialization procedure was developed. The initial horizontal structure of the typhoon was specified based on three storm parameters: central pressure, maximum wind and radius of maximum wind. The maximum winds were provided by the best track data. The central pressure was estimated using an empirical pressure-wind relationship used by the National Hurricane Center, and the radius of maximum wind was estimated from the Japan meteorological observations.

The large-scale environmental wind speed and direction were estimated diagnostically from the storm positions at different times. Other initial environmental conditions, such as the atmospheric temperature and relative humidity profiles and the sea surface temperature were estimated based on the storm intensity change (known from the best track) prior to landfall.

This procedure enabled us to create a simulated Mirielle that was in good agreement with available observations. For more information on historical storm analyses, contact us.