Predictability of Precipitation in a Cloud-Resolving Model

Abstract An ensemble methodology is developed and tested to objectively isolate and quantify meso-β-scale predictability limitations in numerical weather prediction (NWP). The methodology involves conducting an ensemble of limited-area simulations with slightly modified initial conditions (representing small-scale observational uncertainties) and identical lateral-boundary conditions (representing perfect synoptic-scale predictability). The methodology is applied using a nonhydrostatic NWP model with a convection-resolving mesh size of 3 km, using a setup covering the entire European Alps. The initial perturbations of the ensemble members have a small-scale structure with predominant scales between 10 and 100 km. Ensembles for four case studies representing different weather conditions are analyzed for 24-h forecasting periods, with particular attention paid to quantitative precipitation forecasting. The simulations show that the predictability of precipitation amounts differs strongly depending upon the ...

[1]  Fanyou Kong,et al.  An explicit approach to microphysics in MC2 , 1997 .

[2]  Heini Wernli,et al.  Dynamical aspects of the life cycle of the winter storm ‘Lothar’ (24–26 December 1999) , 2002 .

[3]  C. Schär,et al.  A PRECIPITATION CLIMATOLOGY OF THE ALPS FROM HIGH-RESOLUTION RAIN-GAUGE OBSERVATIONS , 1998 .

[4]  D. Lüthi,et al.  Structure and dynamics of an Alpine potential‐vorticity banner , 2003 .

[5]  M. Desgagné,et al.  The Canadian MC2: A Semi-Lagrangian, Semi-Implicit Wideband Atmospheric Model Suited for Finescale Process Studies and Simulation , 1997 .

[6]  Franco Molteni,et al.  Predictability and finite‐time instability of the northern winter circulation , 1993 .

[7]  R. Houze,et al.  The MAP special observing period , 2001 .

[8]  D. Baumhefner,et al.  Predictability Experiments Using a High-Resolution Limited-Area Model , 1987 .

[9]  Roberto Buizza,et al.  Quantitative Precipitation Forecasts over the United States by the ECMWF Ensemble Prediction System , 2001 .

[10]  E. Grimit,et al.  Initial Results of a Mesoscale Short-Range Ensemble Forecasting System over the Pacific Northwest , 2002 .

[11]  F. Molteni,et al.  The ECMWF Ensemble Prediction System: Methodology and validation , 1996 .

[12]  Michael Sprenger,et al.  The Real-Time Ultrafinescale Forecast Support during the Special Observing Period of the MAP , 2002 .

[13]  David J. Stensrud,et al.  Using Initial Condition and Model Physics Perturbations in Short-Range Ensemble Simulations of Mesoscale Convective Systems , 2000 .

[14]  Robert A. Houze,et al.  Air motions and precipitation growth in Alpine storms , 2003 .

[15]  M. Ehrendorfer.  Vorhersage der Unsicherheit numerischer Wetterprognosen: eine Übersicht , 1997 .

[16]  W. Skamarock,et al.  The resolution dependence of explicitly modeled convective systems , 1997 .

[17]  K. Jasper,et al.  Coupled runoff simulations as validation tools for atmospheric models at the regional scale , 2003 .

[18]  E. Epstein,et al.  Stochastic dynamic prediction1 , 1969 .

[19]  Roberto Buizza,et al.  A strategy for high‐resolution ensemble prediction. II: Limited‐area experiments in four Alpine flood events , 2001 .

[20]  E. Epstein,et al.  Stochastic dynamic prediction , 1969 .

[21]  E. Kalnay,et al.  Ensemble Forecasting at NCEP and the Breeding Method , 1997 .

[22]  T. Palmer.  Predicting uncertainty in forecasts of weather and climate , 2000 .

[23]  C. Leith.  Theoretical Skill of Monte Carlo Forecasts , 1974 .

[24]  Roberto Buizza,et al.  The Impact of Horizontal Resolution and Ensemble Size on Probabilistic Forecasts of Precipitation by the ECMWF Ensemble Prediction System , 2002 .

[25]  Roberto Buizza,et al.  The Singular-Vector Structure of the Atmospheric Global Circulation , 1995 .

[26]  R. Rotunno,et al.  Orographic effects on rainfall in MAP cases IOP 2b and IOP 8 , 2003 .

[27]  P. L. Houtekamer,et al.  A System Simulation Approach to Ensemble Prediction , 1996 .

[28]  Jun Du,et al.  Short-Range Ensemble Forecasting of Quantitative Precipitation , 1997 .

[29]  H. Davies,et al.  A lateral boundary formulation for multi-level prediction models. [numerical weather forecasting , 1976 .

[30]  David P. Baumhefner,et al.  Monte Carlo Simulations of Explosive Cyclogenesis , 1994 .

[31]  E. Lorenz.  Deterministic nonperiodic flow , 1963 .

[32]  Ying-Hwa Kuo,et al.  The Interaction between Baroclinic and Diabatic Processes in a Numerical Simulation of a Rapidly Intensifying Extratropical Marine Cyclone , 1991 .

[33]  Richard C. J. Somerville,et al.  On the use of a coordinate transformation for the solution of the Navier-Stokes equations , 1975 .

[34]  Monique Tanguay,et al.  A Semi-implicit Send-Lagrangian Fully Compressible Regional Forecast Model , 1990 .

[35]  Jean Côté,et al.  Inclusion of a TKE Boundary Layer Parameterization in the Canadian Regional Finite-Element Model , 1989 .

[36]  Thomas M. Hamill,et al.  Verification of Eta–RSM Short-Range Ensemble Forecasts , 1997 .