For Sudden Storm Commencements, several methods aiming automatic detection of the events have been proposed. Most of them are based in the analysis of digital geomagnetic field data using some morphological aspects of theses events. Here we present a method using a wavelet analysis on the derivative of H component which is related with the steepness of the rising time. Wavelet analysis is very precise tool for time and frequency determination. A comparative of the results from the detection lists is shown.