Rapid Refresh Frequently Asked Questions
Q: What different versions of the Rapid Refresh are currently running?
A:
- RR (main) - This version is initialized in a 1-h cycle, just like the RUC.
- RR - no-cycle (or, RR-cold-start) - This version is initialized from the GFS every 12h. It provides a good comparison with the primary RR, since it uses the same RR-version of the WRF model. .
A: About 13km, just like the RUC, but, of course, over a much wider geographic area (all of North America), about 3x larger than the RUC.
Q: What model does the RR use?
A:
A RR-configuration of the WRF model, with
- ARW core (v3.0) with
- generally RUC-like physics (Grell-Devenyi convection, Thompson/NCAR microphysics, RRTM longwave radiation, Dudhia shortwave radiation, MYJ turbulent mixing, RUC-Smirnova land-surface model)
- 13-km horizontal resolution, 50 vertical levels, ptop=10hPa, sigma vertical coordinate, 649x648 domain More info here.
Q: What is the history of the operational RUC?
- 1994 - RUC starts running at NCEP, first version with 60-km horizontal resolution and 3-h assimilation cycle.
- 1998 - Implementation of 40-km RUC with 1-h assimilation cycle
- 2002 - Implementation of 20-km RUC with 1-h assimilation cycle
- 2005 - Implementation of 13-km RUC with 1-h assimilation cycle
- 2008 - Implementation of major 13km RUC upgrade, including assimilation of radar reflectivity and TAMDAR.
- 2010 - Planned implementation of Rapid Refresh to replace hourly-updated RUC.