Dear All,

We try to run  RegCM4.7.0 or RegCM5 with FNL data after preparing the data using the script (fnl_dss_ucar_prepare.sh).
All the steps run without error, but after running the model, we get this error:


No more atmosphere here....
 CFL violation detected, so model STOP
 #####################################
 #            DECREASE DT !!!!       #
The logfile of error, namelist and ICBC file are attached.


Another thing, I have a question about the option of 
" isladvec =  0,  ! Semilagrangian advection scheme for tracers and humidity"

What are the impacts of this option?, because sometimes it causes dust concentrations to rise to abnormal values ​​and after turning off this option these huge values ​​stop. 

Thank you in advance.
Best regards,
Zeinab