v0.9.1 fix: Update subsetting procedure in run_prdgen task

[BenjaminBlake-NOAA]

DESCRIPTION OF CHANGES:

• 250 mb UGRD and VGRD have been missing from the CONUS and Alaska pressure level grib2 output files since the update to v0.9.1 on April 18th. This issue was discovered due to the RRFS Python graphics jobs not finding 250 mb UGRD in the CONUS grib2 files. With the v0.9.1 update, 91 records were removed from the prslev files. This caused 250 mb UGRD and 250 mb VGRD to be split up onto two separate files (record 250, the last record in one file, and record 251, the first record in another file). The -submsg_uv option is used with wgrib2, and this caused an issue when UGRD and VGRD were not grouped together. For creating the CONUS and Alaska grib2 files, subtask 1 now processes records 1-251 instead of 1-250, and subtask 2 now processes records 252-500 instead of 251-500.
• If additional products are added/removed to the RRFS grib2 files in the future, we will need to check and make sure the run_prdgen subsetting is still working correctly.
• This change should also be added to the production/RRFS.v1 branch.

TESTS CONDUCTED:

Tested in the v0.9.1 real-time parallel.

Machines/Platforms:

• WCOSS2
  • Cactus/Dogwood
  • Acorn
• RDHPCS
  • Hera
  • Jet
  • Orion
  • Hercules

Test cases:

• Engineering tests
  • Non-DA engineering test
  • DA engineering test
    • Retro
    • Ensemble
    • Parallel
• RRFS fire weather
• RRFS_A:
• RRFS_B:
• RTMA:
• Others:

CONTRIBUTORS (optional):

@MatthewPyle-NOAA suggested the issue could be related to the vector components being split up.

[MatthewPyle-NOAA]

Looks like one to get in quickly!