AN EXPANDED DIGITAL DAILY DATABASE FOR CLIMATIC RESOURCES APPLICATIONS IN THE MIDWESTERN UNITED-STATES

Daily observations of precipitation and maximum and minimum temperatur e from the National Weather Service's cooperative observer network col lected prior to 1948 were keyed into a digital database. This database includes stations in the nine midwestern states of Illinois, Indiana, Iowa, Kentucky, Michigan, Minnesota, Missouri, Ohio, and Wisconsin. T he primary source used in this project was the publication Climatologi cal Data, which began in 1896. This database provides a substantial en hancement to the National Climatic Data Center's TD-3200 Summary of th e Day database, which includes little data prier to 1948. Approximatel y 2 x 10(7) data values were keyed increasing the amount of pre 1948 d igital data by about a factor of 3 and substantially improving its spa tial uniformity. The data were subjected to an extensive set of qualit y control procedures. It is expected that these data will find their g reatest value in applications requiring very long historical records, such as assessments of the risks of extreme events.