ASOS Surface 1-Minute Page 2 Data is digital data set DS- 6406, archived at the National Climatic Data Center (NCDC). A major part of the National Weather Service (NWS) modernization effort in the 1990s is the implementation of the Automated Surface Observations System (ASOS). Data are collected and transmitted automatically. Several sites will not be manned. As new sensors are developed to ... observe additional weather elements (currently not measurable by automatic sensors) they will be implemented. Some of the elements not currently measured include tornados, thunderstorms, hail, drizzle, blowing obstructions to vision, sunshine, snowfall, snow depth and clouds above 12,000 feet. One-minute data are automatically collected and stored on station for 12 hours. Not all ASOS stations provide 1- minute data. The number of stations that will ultimately provide one- minute data has not been determined. Assuming that these stations will be a reasonable sampling of all ASOS stations, 1-Minute data will be from the United States of America including Alaska and Hawaii, plus Puerto Rico. The earliest data is from June, 1998. The major parameters of ASOS 1-Minute Page 2 data are temperature, dew point, precipitation, and pressure.