An Hourly Assimilation–Forecast Cycle: The RUC
| Autor: | Dongsoo Kim, Georg Grell, Barry E. Schwartz, Tracy Lorraine Smith, Tatiana G. Smirnova, Geoffrey S. Manikin, Kevin J. Brundage, Dezso Devenyi, John M. Brown, Stanley G. Benjamin, Stephen S. Weygandt |
|---|---|
| Rok vydání: | 2004 |
| Předmět: | |
| Zdroj: | Monthly Weather Review. 132:495-518 |
| ISSN: | 1520-0493 0027-0644 |
| Popis: | The Rapid Update Cycle (RUC), an operational regional analysis–forecast system among the suite of models at the National Centers for Environmental Prediction (NCEP), is distinctive in two primary aspects: its hourly assimilation cycle and its use of a hybrid isentropic–sigma vertical coordinate. The use of a quasi-isentropic coordinate for the analysis increment allows the influence of observations to be adaptively shaped by the potential temperature structure around the observation, while the hourly update cycle allows for a very current analysis and short-range forecast. Herein, the RUC analysis framework in the hybrid coordinate is described, and some considerations for high-frequency cycling are discussed. A 20-km 50-level hourly version of the RUC was implemented into operations at NCEP in April 2002. This followed an initial implementation with 60-km horizontal grid spacing and a 3-h cycle in 1994 and a major upgrade including 40-km horizontal grid spacing in 1998. Verification of forecasts... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|