Macro to forecast snow potential across the central Andes. 
Looks into:
 -mid-level relative humidity RHML (averaged between 600 and 450 hPa)
 -upward velocities VVEL at 500 hPa
 -500-600 hPa thickness
 -mid-level wind barbs larger than 15kt (averaged between 600 and 300 hPa)

LOOP
RHML CTFC CFCV
SMTH VVEL  500 LT00 C1-3 CLR1 DOTS/
SDIF HGHT  500 HGHT  600 CIN1 LSTN 1450 GRTN 1445 CLRB/
SDIF HGHT  500 HGHT  600 CIN1 LSTN 1445 GRTN 1440 CLR2/
WWMU GRTN   15 CLRE/
WWMU GRTN   25 CLR4/
ENDL