Tornadoes represent the most violent meteorological phenomena known to man, each year resulting in hundreds of millions of dollars in property damage and approximately one hundred fatalities. Extensive data for the contiguous United States, plus Hawaii, have been collected by the National Weather Service, dating from 1950 and updated annually. A statistical analysis of this data can provide a better understanding of the risk posed by tornadoes for a specific geographic region. To carry out such an analysis we have developed the Site Assessment of Tornado Threat (SATT) software. A key features of this model is the use of the concept of the Annual Coverage Fraction (ACF) as a measure of tornado probability. Notice should be taken that this definition of tornado probability is consistent with the FEMA probability model. By means of the SATT software we have calculated and tabulated the probability of tornadoes for the twenty most tornado prone states (excluding Alaska) on both an annual and a month-by-month basis and also for the twenty most tornado prone cities on both an annual and a month-by-month basis. We have also developed color-coded contour maps of tornado probability for various states including Alabama and Georgia, as well as a color- coded map of tornado probability for the United States. A number of technical papers have been published dealing with our work in this area. For a listing of customers we have a table available.