Contains functions to retrieve, organize, and visualize weather data from the NCEP/NCAR Reanalysis (< https://psl.noaa.gov/data/gridded/data.ncep.reanalysis.html>) and NCEP/DOE Reanalysis II (< https://psl.noaa.gov/data/gridded/data.ncep.reanalysis2.html>) datasets. Data are queried via the Internet and may be obtained for a specified spatial and temporal extent or interpolated to a point in space and time. We also provide functions to visualize these weather data on a map. There are also functions to simulate flight trajectories according to specified behavior using either NCEP wind data or data specified by the user.