MM5 Precipitation Verification over the Pacific Northwest during the 1997–99 Cool Seasons*

作者：Brian A. Colle, Clifford F. Mass, Kenneth J. Westrick · 发表于：Weather and Forecasting · 年份：2000 · DOI：10.1175/1520-0434(2000)015<0730:mpvotp>2.0.co;2 · 被引用次数：144 · 研究领域：Meteorological Phenomena and Simulations、Climate variability and models、Precipitation Measurement and Analysis

Precipitation forecasts from the Pennsylvania State University–National Center for Atmospheric Research fifth-generation Mesoscale Model (MM5) are verified for the 1997–98 and 1998–99 cool seasons over the Pacific Northwest. The MM5 precipitation at 36-, 12-, and 4-km horizontal resolution is compared with over 250 NOAA cooperative observer, snow telemetry (SNOTEL), avalanche, and National Weather Service sites in order to evaluate the effects of increasing horizontal resolution and to document spatial variations in model skill. A noticeable improvement in bias, equitable threat, and root-mean-square (rms) error scores occurs as horizontal resolution is increased from 36- to 12-km resolution; however, going from 12- to 4-km resolution improvements in skill are restricted to the heavy precipitation events (>5.08 cm in 24 h). For light to moderate precipitation events, both the 12- and 4-km domains have significant overprediction over the upper windward slopes of the higher terrain. In contrast, for heavy precipitation events there is no widespread overprediction, and all resolutions underpredict precipitation in the lowlands and major gaps in the Cascades. The cool-season undercatchment for selected storage gauges (non-SNOTEL) are estimated using collocated wind, temperature, and precipitation data with undercatchment regression relationships. The undercatchment generally ranges from 25%–40% for exposed high-elevation sites (>1500 m), 15%–20% within major gaps in the Cascades ...