Up-to-date results of recent tropical cyclone research at Colorado State University are presented. Particular attention is paid to new findings which impact on tropical cyclone analysis and forecasting efforts. Observational studies using large amounts of composited rawinsonde, satellite, and aircraft flight data have been performed to analyze global aspects of tropical cyclone occurrences, physical processes of tropical cyclone genesis, tropical cyclone intensity change, environmental factors influencing tropical cyclone turning motion 24-36 hours before the turn takes place, tropical cyclone intensity determination from upper tropospheric reconnaissance, and the diurnal variations of vertical motion in tropical weather systems. (Author).

A program to accept Atlantic hurricane forecasts and create estimates of hurricane strike probabilities is described. The probabilities are based on a tri-modal bivariate normal distribution of forecast errors. The relationship of the occurrence of each mode to such predictors as motion components, geographical position and maximum wind is documented. Results of independent testing are reported. It is expected that strike probabilities will be available during the 1981 hurricane season. The format of input and a description of routine and special products are provided. (Author).