Hi: We do not deal with probability functions in our project. This is mainly because the users (farmers) have difficulty interpreting them. We simply present high-low-average bars to represent the effects of weather variations on yields, profits, run-off, etc. Steve Welch and Richard Vanderlip at Kansas State Univ. developed some nice software (IFDC) which does a good job of displaying cummulative probablity curves. Regards, Barry Jacobson -------------------------------------------------------------- Barry M Jacobson, PhD 112 Rogers Hall Univ of Florida Internet: [log in to unmask] PO Box 110570 Voice: (352) 392-9129 Gainesville, FL 32611-0570 Fax: (352) 392-4092 --------------------------------------------------------------