Local Models at WFO Charleston
The National Weather Service in Charleston is currently running the Weather Research Environmental Modeling System (WRF-EMS), a full featured numerical weather prediction package that incorporates two dynamic cores. The first core is the Advanced Research WRF (ARW) made available from the National Center for Atmospheric Research (NCAR), and the second is the National Center for Environmental Predictions' non-hydrostatic mesoscale model (NMM). The WRF-EMS Package allows for a wide range of configuration, physics, micro-physics, and parameterization schemes. Below is a general description of how the models are configured to run at the National Weather Service in Charleston. Both models are initialized using the NCEP North American NAM12.
Description of the WRF-ARW
The WRF-ARW is executed 8 times per day as a one-way nest. . The model is initialized by a Local Analysis and Prediction System (LAPS) in "hot start" mode. The boundaries are initialized with NCEP's North American Mesoscale (NAM) model at 15 KM resolution. Output for two domains are available, a 15KM outer domain, and a 5KM nested domain centered on West Virginia.
Domain & Run Information for the WRF-ARW:
Primary Time Step : Adaptive Adaptive
Step to Output Time : Yes Yes
Grid dimensions (NX x NY) : 135 x 135 136 x 136
Vertical Layers (NZ) : 45 45
Grid Spacing : 15.00km 5.00 km
Top of Model Atmosphere : 50mb 50mb
Parent Domain : NA Domain 01
Model Physics
Dynamics : Non-Hydrostatic Non-Hydrostatic
Cumulus Scheme : Kain-Fritsch None
Microphysics Scheme : Ferrier Microphysics Ferrier Microphysics
PBL Scheme : Yonsei University Yonsei University
Land Surface Scheme : Noah 4-Layer LSM Noah 4-Layer LSM
Number Soil Layers : 4 4
Surface Layer Physics : Monin-Obukhov Monin-Obukhov
M-O Heat and Moisture : Surface Fluxes On Surface Fluxes On
M-O Snow-cover Effects : Included Included
Long Wave Radiation : RRTMG Scheme RRTMG Scheme
Short Wave Radiation : RRTMG Scheme RRTMG Scheme
ARW Core Model Dynamics
Dynamics : Non-Hydrostatic Non-Hydrostatic
Gravity Wave Drag : Off Off
Time-Integration Scheme : Runge-Kutta 3rd Order Runge-Kutta 3rd Order
Diffusion Scheme : Simple Diffusion Simple Diffusion
6th-order Diffusion : No 6th-Order Diffusion No 6th-Order Diffusion
Eddy Coefficient Scheme : 2D 1st Order Closure 2D 1st Order Closure
Damping Option : W-Rayleigh W-Rayleigh
Damping Depth from Top : 5 Km 5 Km
Damping Coefficient : 0.12 0.12
W Damping : W Damping On W Damping On
Horiz Momentum Advection : 5th Order 5th Order
Horiz Scalar Advection : 5th Order 5th Order
Vert Momentum Advection : 3rd Order 3rd Order
Vert Scalar Advection : 3rd Order 3rd Order
Sound Time Step Ratio : Automatic Automatic
Moisture Advection Option : Positive-Definite Positive-Definite
Scalar Advection Option : Positive-Definite Positive-Definite
TKE Advection Option : Positive-Definite Positive-Definite
Description of the WRF-NMM
The WRF-NMM model is executed 8 times per day for a 3 hour cycle start time. The model is initialized by a Local Analysis and Prediction System (LAPS) in "hot start" mode. In addition, this domain executes with the Digital Filter Initialization (DFI) option turned on. The boundaries are initialized with NCEP's North American Mesoscale Model (NAM) at 12 KM resolution. Output from a single domain with a resolution of 5 KM is available.
Domain & Run Information for the WRF-NMM
Primary Time Step : 10.4 Seconds
Grid dimensions (NX x NY) : 176 x 330
Vertical Layers (NZ) : 45
Grid Spacing : 4.96 km
Top of Model Atmosphere : 50mb
Parent Domain : NA
Digital Filter Initialization Information
DFI Method : DF Launch
DFI Filter : Dolph
DFI Backstop : 40 Minutes
DFI Forwardstop : 20 Minutes
DFI Cut Off : 20 Minutes
Model Physics
Dynamics : Non-Hydrostatic
Cumulus Scheme : None
Microphysics Scheme : Ferrier Microphysics
PBL Scheme : Mellor-Yamada-Janjic
Land Surface Scheme : Noah 4-Layer LSM
Number Soil Layers : 4
Surface Layer Physics : Monin-Obukhov (Janjic)
Long Wave Radiation : GFDL Long Wave Radiation
Short Wave Radiation : GFDL Short Wave Radiation
NMM Core Model Dynamics
Dynamics : Non-Hydrostatic
Gravity Wave Drag : Off
Time-Integration
: Horizontally propagating fast-waves - Forward-backward scheme
: Vertically propagating sound waves - Implicit scheme
Horizontal : Adams-Bashforth
Vertical : Crank-Nicholson
Advection of T, U, and V
Horizontal : Energy and entropy conserving, quadratic conservative, 2nd
order
Vertical : Quadratic conservative, 2nd Order
TKE and Moisture Adv : Explicit, Upstream, Flux-Corrected, Positive Definite,
Conservative
Vertical Diffusion : Handled by PBL and Surface Layer Schemes
Lateral Diffusion : Smagorinsky Non-linear Approach
Divergence Damping : Horizontal component of divergence is damped
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