The NCEP North American Regional Reanalysis products are on Eta 221 grid (32km) at 29 pressure levels. They were produced using Eta 32km/45-layer model. The input data includes all observations used in NCEP/NCAR Global Reanalysis project, and additional precipitation data, TOVS-1B radiances, profiler data, land surface and moisture data, etc. The output analyses are 3-hourly with additional 9 variables in the 3-hour forecasts to reflect accumulations or averages.