Well, get HL SDK and it tells you this about the mentioned temp entity:
Code:
#define TE_EXPLOSION 3 // additive sprite, 2 dynamic lights, flickering particles, explosion sound, move vertically 8 pps
// coord coord coord (position)
// short (sprite index)
// byte (scale in 0.1's)
// byte (framerate)
// byte (flags)
Params 2, 3 and 4 would contain the coordinate.