Accessing NOAA daily temperature and precipitation extremes based on combined/threaded station records

Daily records of both temperature and precipitation are of great interest to the public and many data users. However, numerous station relocations over the years has resulted in inconsistent approaches to combining multi-location data sets, resulting in disparate reporting of record and extreme values at many prominent large metropolitan observing sites.

In the interest of ensuring consistent reporting of climatological data, NOAA's National Climatic Data Center (NCDC), in partnership with the Northeast Regional Climate Center (NRCC), NOAA's National Weather Service/Climate Services Division, and numerous data users, has established a data set of combined (or threaded) period of record daily temperature and precipitation values at approximately 300 NOAA published Local Climatological Data locations. This new data set provides a consistent basis for the reporting of daily, monthly, and annual extremes for the longest period of time meaningful. The development of this data set is especially timely given the increasing availability of historic daily values in digital form for the first half of the 20th century (and earlier in some cases).

This presentation provides a discussion on the methodology for establishing multi-location combined (or threaded) station data sets, preliminary applications of the data, and schedules for its public release.