Automated database of mesocyclones from the HIRLAM(INM)-0.5 degrees analyses in the western Mediterranean

An automated procedure has been developed to detect and select mesoscale cy clones and describe their tracks by means of the numerical analysis model, the HIRLAM(INM)-0.5 degrees, operational at the Spanish Institute of Meteor ology (INM). This procedure gives us a description of features of these cyc lones, such as their frequency of appearance, geographical distribution and horizontal dimensions, and it also enables us to study the movement and th e evolution of the cyclone centres. This procedure was developed in order t o obtain an automated database of Mediterranean cyclones. To check the perf ormance of this method, the distribution of cyclones was compared with the distribution obtained from a manual catalogue of mesoscale cyclones, and se lected cases were studied using both methods. Some results obtained for the western Mediterranean are presented. A large number of cyclones are detect ed and most of them are located in specific zones, such as the Gulf of Geno a, south of the Pyrenees, south of the Iberian Peninsula and the Alboran Se a. The cyclones follow preferred tracks, which are different depending on t he season. Copyright (C) 2001 Royal Meteorological Society.