Abstract ICARO is a software package developed to construct, examine, and compare wind fields in complex terrain. The user may interactively run mathematical models to evaluate three dimensional wind fields from available experimental measurements. Graphics and post-processing programs are implemented in ICARO to analyze and intercompare wind field results, as well as verify results with measurements. These features may be extended to results from other fluid-dynamic models. Different vertical grid resolutions are possible for verification of models performance. ICARO has proved to be a very quick and useful tool for both case studies and field experiments. The package is written in FORTRAN 77 and runs on DEC-VAX computers with a VMS operating system using NCAR graphics routines.