The Integrated Terminal Weather System (ITWS) is a development program initiated by the Federal Administration (FAA) to produce a fully automated, integrated terminal weather information system to improve the safety, efficiency and capacity of terminal area aviation operations. The ITWS will acquire data from FAA and National Weather Service sensors as well as from aircraft in flight in the terminal area. The ITWS will provide Air Traffic personnel with products that are immediately usable without further meteorological interpretation. Among the products are current terminal area weather, short-term (0-30 minute) predictions of significant weather phenomena, and the Terminal Winds product. The terminal winds product is the component of the ITWS which produces estimates of the horizontal winds on a three dimensional grid of points encompassing an airport terminal region. It uses information from a variety of sensors, including Doppler weather radars. In 1992, an operational test of an initial prototype Terminal Winds system was conducted at the MIT Lincoln Laboratory testbed in Orlando, FL. This report describes our evalution of the initial Terminal Winds prototype.