The CSF tools use both precipitation and temperature data.
For temperature, the data are daily temperature observations from the National Weather Service (NWS) Cooperative Observer Network. The data is interpolated to a 5km x 5km grid, accounting or elevation differences. The interpolation follows the method of DeGaetano and Belcher (2007), who are CSF collaborators at the Northeast Regional Climate Center (NRCC)
Daily maximum and minimum temperatures are obtained from the 25 hourly initialization fields of the 40 km resolution NWS Rapid Update Cycle (RUC) model.
For precipitation, the data comes from National Weather Service (NWS) radar data, and are represented at a grid of 4km x 4km, using the methods of DeGaetano and Wilks (2009). Daily adjustments which are computed as a bias, are made daily from rain gauge (observed) data.