CELLTRACK — Convective cell tracking algorithm and its use for deriving life cycle characteristics

The CELLTRACK algorithm was developed in the Czech Hydrometeorological Institute (CHMI) as a complementary radar-based nowcasting tool to the COTREC algorithm for convective situations. This article contains a description of the identification, tracking and extrapolation techniques used in CELLTRACK. Also discussed is an evaluation of CELLTRACK tracking performance and a comparison of its forecast skill with the COTREC algorithm. CELLTRACK gives a performance similar to COTREC for approximately the first 30 min, however it can catch the movement of a convective storm deviating from the movement of surrounding convective storms. CELLTRACK is used operationally in the CHMI and is available to forecasters via the JSMeteoView visualisation application. It has also been used for creating a 2002–2006 statistic of radar and satellite characteristics of convective cells over the area of the Czech Republic. There are obvious dependencies of mean convective cell characteristics as maximum reflectivity level or convective cell area on convective storm lifetime and zero isotherm level.