Table 4.248 has CSV formatting issues. Updating lines 2 and 3 per below seems to fix the issue:
Method used to derive data values for a given local time,,0,,Nearest forecast or analysis time to specified local time,,,Operational
Method used to derive data values for a given local time,,1,,Interpolated to be valid at the specified local time,,,Operational
Branch
https://github.com/wmo-im/GRIB2/tree/iss117
Summary and purpose
Table 4.248 has CSV formatting issues. Updating lines 2 and 3 per below seems to fix the issue: