Panoply is a data viewer that quickly displays geo-referenced arrays in netCDF, HDF, and GRIB formats. This recipe shows the steps that will create a wind vector plot in Panoply. Surface winds on October 29, 2012, over the northeast United States during ‘Superstorm’ Sandy Estimated time to complete following procedures: 5 minutes ftp://goldsmr2.sci.gsfc.nasa.gov/data/s4pa/MERRA/MAT1NXSLV.5.2.0/2012/10/MERRA300.prod.assim.tavg1_2d_slv_Nx.20121029.hdf Panoply works with geo-referenced data in NetCDF, HDF, and GRIB format for both gridded (Level 3) and swath (Level 1 and Level 2) data. To be plotted by Panoply, data set variables must be tagged with metadata information using a convention such as Climate and Forecast (CF). If a variable is not CF-compliant, its metadata will be displayed, but its image may not plot. This recipe has been tested on PC (Panoply version 3.1.8) and on Mac (Panoply version 4.0.4). Panoply version 3.1.1 or later works with GRIB files, including a listing of all parameters, along with detailed metadata information. Source.