A project is underway to consolidate and unify various precipitation products for improved applications in weather and climate. The final goal of the project is the construction of a suite of gauge-based, satellite-derived and gauge-satellite merged precipitation analyses with consistent quantity and improved quality.

First, station reports of hourly and daily precipitation are collected from various sources and quality controlled to remove suspicious records. Gauge-based analyses of daily and hourly precipitation analyses are then constructed by interpolating these quality controlled station reports applying the method of Xie et al. (2007) which takes into account of orographic effects in precipitation. As of July 2011, gauge-based analyses of daily precipitation have been constructed on a 0.25olat/lon grid over the global land for a 33-year period from 1979 and on a 0.125olat/lon grid over CONUS for a 64-year period from 1948. The daily gauge analysis is updated on a real-time basis.

At the meantime, a technique has been developed at NOAA/CPC to integrate the precipitation information from the passive microwave (PMW) retrievals and the infrared (IR) observations aboard geostationary platforms into a high-quality, high-resolution global precipitation estimates. Called CPC Morphing technique (CMORPH, Joyce et al. 2004), this technique has been applied to produce integrated satellite precipitation estimates on an 8kmx8km grid over the globe from 60oS to 60oN and in a time step of 30-min from 1998 to the present.

The gauge-based daily analysis and the CMORPH satellite estimates are further combined for the production of gauge-satellite merged analyses of precipitation with improved quantitative accuracy. To this end, bias in the CMORPH satellite estimates is removed through calibrating the probability density function (PDF) of CMORPH against that for the concurrent daily gauge analysis. The bias-corrected CMORPH is further combined with the gauge analysis through the OI framework, in which the bias-corrected CMORPH and the gauge data are used as the ‘first-guess' and the ‘observations', respectively.

A set of procedures have been established at NOAA/CPC to generate the above mentioned products on a quasi real-time basis. The resulting global precipitation analyses have been used widely in both research and operation in weather, climate and hydrology. Several examples for the applications will be illustrated. In addition, recent progress on the development of hourly precipitation analyses over CONUS will be reported at the conference.