constant model output after 240h

Hi,

 

 I am running the ufs- GFS16vbeta version in different resolutions C96, C192, C384
 with an initialisation von ncep gfs00.grib2.

In all test the output is not changing after 240h - all time steps are identical.
Does anybody know what could be the problem? Any help is very appreciated.
 

 

Best regards Ulrich