Illustrative Analysis on Doppler Radar Data Applicability with A Squall Line Process
Overall analysis is conducted based on conventional data and Doppler data for a squall line process with longer life history on September 7,2008 for the purpose of a preliminary discussion about the applicability of several Doppler products. The analysis confirms that during each development stage of the thunderstorm cells,system fluid field and environmental wind field,whose interaction will reveal a special distribution on?radar echoes,can be observed from the radar data. Such a distribution as a small patch of negative (positive) speed zone with homogeneous values nested in a large area of positive (negative) speed zone is frequently misjudged as meso-cyclones,however it is mid altitude radial convergence,MARC from mid altitude of convective system in fact. A velocity diagram(V26)of favorable elevation angle with the superposition of tracking information (58 STI)will facilitate the analysis of storm development stages. Discussion on the forecast accuracy at each cell development stage for storm tracking information product,along with the applicability study of other products are expected to improve the current short-term forecast when those conclusions are to be used in short-term forecast and diagnosis.