Unmanned Aircraft System (UAS) operations in the National Airspace System (NAS) are rapidly increasing, and the trend is expected to continue as regulations are refined to allow broader access to the airspace. The unique characteristics of UAS (e.g., extensive operations in populated areas at altitudes below 500 feet, speed capability, and control systems) may drive the need for new and unique operational strategies, many of which are highly dependent on weather conditions. The objective of this study is to identify information gaps in the ability of current weather products to meet the needs of UAS operations, and provide a roadmap of research required to fill the gaps. There are several trends in the information gaps that surfaced repeatedly. A key item is the availability of weather observations, and forecasts tailored for on-airport operations are not necessarily sufficient for off-airport operations. Surveyed users indicated that airport-specific weather information (e.g., METAR, TAFs, etc.) do not readily translate to conditions at remote launch locations, which may be 10-30 miles from the nearest airport, and are influenced by local terrain, vegetation, and water sources. Moreover, the results show significantly less weather information available to support low-altitude flight than for typical manned-flight profiles. Beyond Visual Line of Sight (BVLOS) operations are found to have higher need for weather forecasts, uncertainty information, and contingency planning than Visual Line of Sight (VLOS) operations. Furthermore, the study identifies specific gaps related to how the airspace should be managed to mitigate safety and efficiency impacts to UAS operations. The research roadmap is composed of research recommendations that are derived from the aforementioned weather information gaps. In total, there are 14 specific recommendations that define the roadmap. The first two recommendations are not explicitly tied to specific gaps; rather they are based on lessons learned through the course of research in this study. The remaining recommendations are ordered such that their priority is based on their overall significance to the operation, the maturity of the operation, and any dependence among other recommendations.