INITIALIZATION OF A MODELED CONVECTIVE STORM USING DOPPLER RADAR DERIVED FIELDS

A method is developed to initialize convective storm simulations with Doppler radar-derived fields. Input fields for initialization include velocity, rainwater derived from radar reflectivity, and pressure and temperature fields obtained through thermodynamic retrieval. A procedu re has been developed to fill in missing wind data, followed by a vari ational adjustment to the filled wind field to minimize ''shocks'' tha t would otherwise cause the simulated fields to deteriorate rapidly. A series of experiments using data from a simulated storm establishes t he feasibility of the initialization method. Multiple-Doppler radar ob servations from the 20 May 1977 Del City tornadic storm are used for t he initialization experiments. Simulation results are shown and compar ed to observations taken at a later time. The simulated storm shows go od agreement with the subsequent observations, though the simulated st orm appears to be evolving faster than observed. Possible reasons for the discrepancies are discussed.