This dataset contains the Coded Surface Bulletin (CSB) dataset reformatted as netCDF-4 files. The CSB dataset is a collection of ASCII files containing the locations of weather fronts, troughs, high pressure centers, and low pressure centers as determined by National Weather Service meteorologists at the Weather Prediction Center (WPC) during the surface analysis they do every three hours. Each bulletin is broadcast on the NOAAPort service, and has been available since 2003. Each netCDF file contains one year of CSB fronts data represented as spatial map data grids. The times and geospatial locations for the data grid cells are also included. The front data is stored in a netCDF variable with dimensions (time, front type, y, x), where x and y are geospatial dimensions. There is a 2D geospatial data grid for each time step for each of the 4 front types—cold, warm, stationary, and occluded. The front polylines from the CSB dataset are rasterized into the appropriate data grids. Each file conforms to the Climate and Forecast Metadata Conventions. There are two large groupings of the CSB netCDF files. One group uses a data grid based on the North American Regional Reanalysis (NARR) grid, which is a Lambert Conformal Conic projection coordinate reference system (CRS) centered over North America. The NARR grid is quite close the the spatial range of data displayed on the WPC workstations used to perform surface analysis and identify front locations. The native NARR grid has grid cells which are 32 km on each side. Our grid covers the same extents with cells that are 96 km on each side. The other group uses a 1° latitude/longitude data grid centered over North America with extents 171W – 31W / 10N – 77 N. The files in this group are identified by the name MERRA2, because they were used with data from the NASA MERRA-2 dataset, which uses a latitude/longitude data grid. There are a number of files within each group. The files all follow the naming convention codsus_[masked]_<grid>_<subproduct>.nc, where [masked] indicates that the presence of the word masked is optional and <grid> is either merra2-1deg or narr-96km. The <subproduct> element is either the word mask or the sequence <n>wide_<year>, where <n> is the front width and <year> is the year for the data stored in the file. The codsus_<grid>_mask.nc file is a file containing a single data grid that delineates the envelope of the geospatial region where there are, on average, 40 or more front crossing of any type per year. The WPC meteorologists don't attempt to provide equal levels of attention to every grid cell displayed on their workstations. The files of the form codsus_masked_<grid>_<n>wide_<year>.nc have all had the mask described above applied to exclude parts of fronts that extend past the envelope. The files of the form codsus_<grid>_<n>wide_<year>.nc have no masking applied. The <n>wide portion of the file names takes two forms—1wide and 3wide. The fronts in the1wide files were rasterized by drawing the front polylines with a width of one grid cell. The fronts in the 3wide files were rasterized by drawing the front polylines with a width of 3 grid cells. Within each grid group, there are five subsets of files: codsus_masked_<grid>_1wide_<year>.nc codsus_masked_<grid>_3wide_<year>.nc codsus_<grid>_1wide_<year>.nc codsus_<grid>_3wide_<year>.nc codsus_<grid>_mask.nc The primary source for this dataset is an internal archive maintained by personnel at the WPC and provided to the author. It is also provided at DOI 10.5281/zenodo.2642801. Some bulletins missing from the WPC archive were filled in with data acquired from the Iowa Environmental Mesonet.