Through a closely collaborative effort with OHD and ESRL, NCEP Environmental Modeling Center has developed Climatology-Calibrated Precipitation Analysis (CCPA), a new precipitation analysis at about 5km resolution with 6 hour accumulation for bias correction and downscaling. CCPA has been running in real-time and updating twice daily since July 14, 2010, and the product is available to users at five basic grids over the continental US from 2002 to present. This product is generated by combining two widely used available datasets to take advantage of the higher reliability of the CPC Unified Global Daily Gauge Analysis and the higher temporal and spatial resolution of the Stage IV dataset based on multi-sensor observations. This product is being used in several important studies. In particular, bias correction and downscaling the precipitation forecast from GEFS has made progress and presented in the previous meeting.

In addition to the existing 6-hourly accumulated analysis, CCPA product has been extended to include 3-hourly accumulations in recent upgrade. In response to a need for higher temporal resolution precipitation analysis for use in short range forecast calibration and verification, 3-hourly analysis has been developed and successfully implemented within the CCPA production package since July 2011. CCPA 3-hourly accumulated precipitation analysis is produced by splitting each 6-hourly accumulated precipitation analysis based on a proportion calculated from hourly Stage II (over the Northwest River Forecast Center) or Stage IV (all other CONUS River Forecast Centers) estimation at each HRAP grid cell. It is then interpolated/extrapolated to the other grids. The CCPA 3-hourly analysis covers the same domain as the CCPA 6-hourly analysis and is available for the same five grids. Its long term historical archive will be generated in the future.