Significant Tornado Parameter

Credit: Richard Thompson, NOAA SPC.

This is the variant based on surface based CAPE, contributed to the library by Richard Thompson of the NOAA SPC.

capesfc = surface based CAPE
plcl = pressure at lifting condensation level
srh1km = storm-relative helicity, 0-1km
shear06 = 0-6km bulk shear

'define stpsfc=(capesfc/1500)*((2000-plcl)/1000)*(srh1km/150)*(shear06/20)'