Explanation key for variables in sounding parameter files:

sid - station id
wmoid - wmo number
yr - year
mo - month
dy - day
ts - surface temperature (F)
td - surface dewpoint (F)
li - lifted convective index
swt - sweat convective index
k   - k convective index
tt  - total-totals convective index
pw  - precipitable water (cm)
hwbz - height of wet bulb zero temperature (m)
cape - covective available potential energy (J/kg)
cin  - convective inhibit (J/kg)
lcl  - lifting condensation level (mb)
lfc  - level of free convection (mb)
vvm  - vertical velocity max (m/s)
hne  - heating energy (J/kg) to reach convective condensation level
tc   - convective temperature

Caution: these parameters have been computed from sounding data that 
has undergone only very limited quality control and thus may be subject 
to large errors. A field with a "*******" or "nan" in it, should be 
regarded as bad or missing data.