Example Fortran program that reads a GrADS binary file

read_grads_example.f90

program read_grads_example

  ! Example program that reads a flat binary file
  ! 
  ! With GNU Fortran, compile as:
  !
  !   gfortran -fconvert=big-endian read_grads_example.f90
  !
  ! With Intel Fortran, compile as:
  !
  !   ifort -convert big_endian -assume byterecl read_grads_example.f90

  ! use portable 4-byte reals
  use iso_fortran_env, only: real32

  implicit none

  character(len=*), parameter :: filename = 'taucw.grd' ! file to read
  integer, parameter :: im = 2880, jm = 1440, nm = 60 ! grid dimensions
  integer :: fileunit
  integer :: record_length

  real(kind=real32) :: field(im,jm,nm) ! 3-d array to store data

  record_length = storage_size(field) / 8 * size(field)
  open(newunit=fileunit, file=filename, access='direct', recl=record_length)
  read(unit=fileunit, rec=1) field
  close(fileunit)

  write(*,*) 'Min / max: ', minval(field), maxval(field)

end program read_grads_example

Thanks @milancurcic !