On April 1, 1995, the National Centers for Environmental Prediction (NCEP) began routine generation of N. America analysis and forecast fields. This new "Early Eta" system became operational on 12Z 12 Oct 1995, and output from this operational system began to populate the CPPA/GAPP tape archive on 00Z 1 Nov 95 (prior to 1 Nov 95 the tape archive was populated by the output from the pre-implementation version of the same model). The output files include A) gridded 3-D and 2-D atmospheric fields of wind velocity, temperature, humidity, and cloud water, as well as a whole host of surface, sub-surface, and near surface fields and B) hourly time series output at a large set of selected sites (about 600) over N. America. On June 20, 2006, Eta was replaced by the nonhydrostatic WRF-NMM as the NCEP mesoscale operational model.
NCEP CPPA/GAPP/GEWEX related information and fields are also available via anonymous ftp at ftp.ncep.noaa.gov :