The Atlantic HURISK model: Adaptation to other tropical cyclone basins

The North Atlantic HURISK (HUrricane RISK) model provides a complete description of the tropical cyclone climate, including risk analysis, for any site over the basin. Since the original development of the model at the TPC/NHC in the early- to mid-1980's, frequent activation for Atlantic area commercial and military interests has led to many technical advances to the model itself and cosmetic improvements to the largely graphical output. Some of these will be described

User demand has led to an extension of HURISK to other basins and versions have been developed for all regions except for the Bay of Bengal and the Arabian Sea. The model requires many data bases such as radial wind profiles, radii of maximum wind, location and time of landfall as well as the usual 6-hourly best-track data. The main purpose of this paper is to discuss some of the anticipated and unanticipated problems in obtaining or simulating these data bases for basins other than the Atlantic.

A major problem in extending HURISK into the Southern Hemisphere was the unavailability of a sufficiently detailed, homogeneous and lengthy storm history data set for the entire hemisphere. The South Indian Ocean area near 100E was particularly troublesome in that respect. Another serious problem in activating HURISK for other basins was the need for assignment of a friction factor and maximum possible intensity of cyclones. Both are very important model inputs but rather difficult for users to quantify. Objective methods for determining these parameters will be described.