WMO Solid Precipitation Intercomparison Experiment

WMO initiated the organization of an intercomparison of instruments and methods of observation of solid precipitation and snow on the ground, known as the WMO Solid Precipitation Intercomparison Experiment (SPICE) in 2010. SPICE is a joint effort of the WMO Members and instrument manufacturers. The formal intercomparison commenced in December 2012, being organized on 20 sites, in 15 countries, in the Northern and the Southern Hemisphere. SPICE will report on current and new sensors and systems, representing most of the technologies used internationally for measuring solid precipitation and snow on ground, using multiple measuring principles, and installed in multiple configurations. The experiment will take place over several winter seasons. The multi- site intercomparison will allow the concurrent assessment of the same sensor models in multiple climates, and over a broad range of operational conditions. The paper will present the organization of the experiment, and preliminary results regarding the derivation of the reference observations for the experiment, with a focus on results from participating sites in USA and Canada.