This is the experimental version of the GFS and it is not always available.
4 times per day 04:44 GMT, 10:45 GMT, 16:45 GMT, 22:45 GMT
The GFSP is the experimental version of the GFS model. It is not always available. NCEP usually move it into production to replace the existing GFS model once testing has been successfully completed and the verification statistics show it to be more accurate.
A subset of the GFS charts is plotted when the GFSP is running on TWO
Model information from NCEP