I have been Googling, without success, to see whether I could discover how the six-digit stations IDs in sfstns.tbl are chosen. Clearly, they are five-digit WMO station index numbers with a sixth digit added. Does anybody on this list know how the sixth digit is determined? Thank you. _______________________________ Paul H. Harder II, Ph.D., AMS Meteorologist and Software Developer Weather Insight, L.P. www.WeatherInsight.com Direct: 713-361-4966, Tech Support: 713-361-4985 Weather Insight - Redefining Weather Risk Management This e-mail is strictly confidential, privileged, and only for the use of the intended recipients. Please notify sender immediately if you have received this in error. Unauthorized interception of this e-mail is a violation of federal criminal law.