Categorical Outlook
https://www.nco.ncep.noaa.gov/pmb/docs/grib2/grib2_doc/grib2_table4-224.shtml
No Risk Area
General Thunderstorm Risk Area
Slight Risk Area
Moderate Risk Area
High Risk Area
Dry Thunderstorm (Dry Lightning) Risk Area
Critical Risk Area
Extreamly Critical Risk Area
Missing