0 0 NESTED GRID MODEL (NGM)
1 1 AVIATION MODEL (AVN)
2 2 MEDIUM RANGE FORECAST (MRF) MODEL
3 3 GLOBAL DATA ASSIMILATION SYSTEM (GDAS) FORECAST MODEL
4 4 PRIOR SOUNDINGS (WITHIN 3 HOURS OF CURRENT TIME)
5 5 CLIMATOLOGY
15 15 MISSING VALUE
