TITLE

An Hourly Assimilation–Forecast Cycle: The RUC

AUTHOR(S)
Benjamin, Stanley G.; Dévényi, Dezsö; Weygandt, Stephen S.; Brundage, Kevin J.; Brown, John M.; Grell, Georg A.; Kim, Dongsoo; Schwartz, Barry E.; Smirnova, Tatiana G.; Smith, Tracy Lorraine; Manikin, Geoffrey S.
PUB. DATE
February 2004
SOURCE
Monthly Weather Review;Feb2004, Vol. 132 Issue 2, p495
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
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 from the latest 20-km version is presented using rawinsonde and surface observations. These verification statistics show that the hourly RUC assimilation cycle improves short-range forecasts (compared to longer-range forecasts valid at the same time) even down to the 1-h projection.
ACCESSION #
12164734

 

Related Articles

  • Assessing Predictability with a Local Ensemble Kalman Filter. Kuhl, David; Szunyogh, Istvan; Kostelich, Eric J.; Gyarmati, Gyorgyi; Patil, D. J.; Oczkowski, Michael; Hunt, Brian R.; Kalnay, Eugenia; Ott, Edward; Yorke, James A. // Journal of the Atmospheric Sciences;Apr2007, Vol. 64 Issue 4, p1116 

    In this paper, the spatiotemporally changing nature of predictability is studied in a reduced-resolution version of the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS), a state-of-the-art numerical weather prediction model. Atmospheric predictability is assessed...

  • Impact of TMI SST on the Simulation of a Heavy Rainfall Episode over Mumbai on 26 July 2005. Deb, S. K.; Kishtawal, C. M.; Pal, P. K.; Joshi, P. C. // Monthly Weather Review;Oct2008, Vol. 136 Issue 10, p3714 

    In this study the simulation of a severe rainfall episode over Mumbai on 26 July 2005 has been attempted with two different mesoscale models. The numerical models used in this study are the Brazilian Regional Atmospheric Modeling System (BRAMS) developed originally by Colorado State University...

  • Does An ENSO-Conditional Skill Mask Improve Seasonal Predictions? Pegion, Kathy; Kumar, Arun // Monthly Weather Review;Dec2013, Vol. 141 Issue 12, p4515 

    The National Centers for Environmental Prediction Climate Prediction Center uses statistical tools together with the Climate Forecast System (CFS) to produce forecasts for seasonal outlooks of U.S. temperature and precipitation. They are combined using an optimal weighting procedure that depends...

  • Assimilation of SSM/I Radiances in the NCEP Global Data Assimilation System. Okamoto, Kozo; Derber, John C. // Monthly Weather Review;Sep2006, Vol. 134 Issue 9, p2612 

    A technique for the assimilation of Special Sensor Microwave Imager (SSM/I) data in the National Centers for Environmental Prediction (NCEP) global data assimilation and forecast system is described. Because the radiative transfer model used does not yet allow for cloud/rain effects, it is...

  • The Prediction of Extratropical Storm Tracks by the ECMWF and NCEP Ensemble Prediction Systems. Froude, Lizzie S. R.; Bengtsson, Lennart; Hodges, Kevin I. // Monthly Weather Review;Jul2007, Vol. 135 Issue 7, p2545 

    The prediction of extratropical cyclones by the European Centre for Medium-Range Weather Forecasts (ECMWF) and the National Centers for Environmental Prediction (NCEP) ensemble prediction systems (EPSs) has been investigated using an objective feature tracking methodology to identify and track...

  • MOS Uncertainty Estimates in an Ensemble Framework. Glahn, Bob; Peroutka, Matthew; Wiedenfeld, Jerry; Wagner, John; Zylstra, Greg; Schuknecht, Bryan; Jackson, Bryan // Monthly Weather Review;Jan2009, Vol. 137 Issue 1, p246 

    It is being increasingly recognized that the uncertainty in weather forecasts should be quantified and furnished to users along with the single-value forecasts usually provided. Probabilistic forecasts of “events” have been made in special cases; for instance, probabilistic forecasts...

  • Lagged Ensembles, Forecast Configuration, and Seasonal Predictions. Chen, Mingyue; Wang, Wanqiu; Kumar, Arun // Monthly Weather Review;Oct2013, Vol. 141 Issue 10, p3477 

    An analysis of lagged ensemble seasonal forecasts from the National Centers for Environmental Prediction (NCEP) Climate Forecast System, version 2 (CFSv2), is presented. The focus of the analysis is on the construction of lagged ensemble forecasts with increasing lead time (thus allowing use of...

  • Estimation of Predictability with a Newly Derived Index to Quantify Similarity among Ensemble Members. Yamada, Tomohito J.; Koster, Randal D.; Kanae, Shinjiro; Oki, Taikan // Monthly Weather Review;Jul2007, Vol. 135 Issue 7, p2674 

    This study reveals the mathematical structure of a statistical index, Ω, that quantifies similarity among ensemble members in a weather forecast. Previous approaches for quantifying predictability estimate separately the phase and shape characteristics of a forecast ensemble. The diagnostic...

  • Simulation and evaluation of 2-m temperature over Antarctica in polar regional climate model. Xin, YuFei; Bian, LinGen; Rinke, Annette; Dethloff, Klaus // SCIENCE CHINA Earth Sciences;Apr2014, Vol. 57 Issue 4, p703 

    The European Centre for Medium-Range Weather Forecasts Reanalysis ERA40, National Centers for Environmental Prediction (NCEP) 20th-century reanalysis, and three station observations along an Antarctic traverse from Zhongshan to Dome-A stations are used to assess 2-m temperature simulation skill...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics