Improvement of microphysical parameterization through observational verification experiment

During the past several years, there was increasing evidence of deficiencies in bulk microphysical parameterizations in numerical weather prediction models. Improvements in these parameterizations were difficult because coincident and comprehensive measurements of both the basic-state flow and microphysical parameters were not available. In response to the need for such data, two field campaigns were carried out: an offshore frontal precipitation study off the Washington coast in January-February 2001, and an orographic precipitation study in the oregon Cascade mountains in November-December 2001.