Verification of RUC2 Precipitation Forecasts using the NCEP Multisensor Analysis

The Rapid Update Cycle (RUC) model was developed at NOAA's Forecast Systems Laboratory and has been implemented operationally at the National Centers for Environmental Prediction (NCEP). The RUC has a unique role within the U.S. National Weather Service in that it is the only operational system that provides updated national-scale Numerical Weather Prediction (NWP) analyses and forecasts more often than once every 6 hours. Qualitative Precipitation (QPF) forecasts from the RUC are produced hourly out 12-h in advance of the initial cycle run time.

At NCEP an experimental real-time hourly, multisensor U.S. National Precipitation Analysis (NPA) was developed in the mid-1990s. Over the lower 48 states, this analysis merges approximately 2500 hourly rain gauge observations obtained in real time with hourly digital precipitation radar estimates.

The NPA and the RUC give us a unique opportunity to examine frequently updated short-range QPF characteristics of an operational NWP model. Standard QPF Skill scores for 1- and 3-h accumulated RUC precipitation forecasts will be presented for seasonal data from 1999. A brief discussion of the ongoing development of the RUC and NPA systems will be included.