Is the precipitation record of Charlotte Douglas International Airport representative of the Charlotte metropolitan area?

The official weather and climate record for most cities typically comes from an automated surface observation station (ASOS) operated and maintained by the National Oceanic and Atmospheric Administration (NOAA) and often located near the airport. During convective precipitation, it is not unusual for only a portion of an urban area to receive precipitation, and that area may or may not include an ASOS. For Charlotte, NC the ASOS (KCLT) is located at Charlotte-Douglas International Airport (CLT), which is on the western side of the Charlotte metropolitan area. In order to examine how representative the precipitation record from KCLT is for the entire Charlotte metropolitan area precipitation data from KCLT was compared to precipitation data from six personal weather stations (PWS) available via the Weather Underground and located around the metropolitan area. Contingency tables were utilized to to try to quantify statistically the representativeness of KCLT. Both an accuracy and critical success ratio were calculated for a series of PWS stations and examined over monthly, seasonal, and yearly time scales. The scores for each PWS were compared to the distance from KCLT to try and ascertain if there was a clear distance limitation to the representativeness of asos observed precipitation. While this study examined only the occurrence of precipitation on a daily time scale, and not the amount of precipitation, the results indicate that in convective situations a single asos can not fully capture the precipitation occurrence in a large metropolitan area.