I understand that rather than using relative humidity, mixing ratio Is a good predictor for cloud? Any thoughts? Regards Howard Staines Metris Limited phone 0800 372 433 - mobile 027 2785586 - P O Box 5136 Greenmeadows, NAPIER email info at metris.co.nz - info at metscape.net.nz - website www.metris.co.nz - www.metscape.net.nz