Thursday, 15 January 2004: 4:00 PM
Application of the Rapid Update Cycle at 10-13 km—Initial testing
To gain experience with the RUC system at anticipated higher horizontal resolution in operations at NCEP,testing of the RUC model at 10km resolution in regional domains of 2500 x 2000 km has been performed since winter 2000-2001. Real-time testing of a full national-scale domain at 13-km resolution will begin in fall 2003. Most recently, the 10km RUC model has been run over a domain covering much of eastern U.S. and southeastern Canada and having its southwestern corner over Oklahoma. This has been run in support of NOAA pilot programs to improve surface temperature forecasts with special operations in summers of 2002 and 2003. The northeast 10km RUC continued to run through winter 2002-2003. We will present results of objective verification of the 10km RUC forecasts against rawinsonde observations over this domain (about 35 rawinsondes) and compare against the 20km RUC running over the CONUS domain for those same stations. Many local forecasts related to surface effects have been shown to be considerably improved over those from 20km RUC (operational in April 2002),including orographic precipitation, lake-effect snow, and terrain-induced circulations. We will concentrate on behavior of surface wind, temperature and precipitation fields, forecast fields known to be sensitive to improved resolution of orography. We will also present results and example forecasts from the 13-km CONUS version of the RUC, which will be the next proposed resolution for the operational RUC at NCEP.