The New GFS weather model
Papin notes that the way that FV3 handles convection and cumulus
clouds (cumulus parameterization) is unchanged from the previous GFS. He says
this is one reason why an unrealistically large number of early-season
hurricanes tend to appear in long-range GFS output for the Caribbean, where a
predominant large-scale gyre may include pockets of spin (vorticity) that the
model erroneously develops.