SOO/STRC WS Eta Frequently Asked Questions

	Questions
	I'm just getting started. Where do I begin? Why develop and support a NWP package for the WFOs? Why would I want to run the workstation Eta instead of other mesoscale models such as MM5 or RAMS? What platforms does the workstation Eta run on? What type of PC do I need to run the workstation Eta? Do I need a compiler for the workstation Eta? Do I have to use the same schemes used in the operational model? What are my options? What is the format of the WS Eta output files? What is the format of the WS Eta initialization files?
Q	I'm just getting started. Where do I begin?
	A. Get the Files 1. wsetadir.tar.gz 2. worketa_soostrc_*.tar.gz 3. worketa_topo.tar.gz 4. worketa_sfc_LittleE.tar.gz (for DEC or Linux), or worketa_sfc_BigE.tar.gz (for almost everything else) 5. Binary files for your platform is you don't have a compiler. Precompiled binaries are available in the binary directory. B. Read the installation instructions 1. Please read SOO/STRC WS Eta Installation Procedure C. Run the Model 1. Please read Running the SOO/STRC WS Eta D. For further questions see the WS Eta users Guide
Q	Why Develop and Support a NWP Package for the WFOs?
	The Science Operations Officer/Science and Training Resource Center (SOO/STRC) version of the workstation (WS) Eta modeling package was developed to promote the local use of numerical weather prediction models in the Weather Forecast Offices (WFOs) and to achieve the following three goals set by the SOO Science and Training Resource Coordinator (SOO STRC): 1. To improve the knowledge and use of NWP models and issues at the local level 2. To advance the forecasting process through an improved understanding of mesoscale processes and the use of non-traditional diagnostic tools 3. To increase participation within the WFOs in developing and executing NWP studies to examine local forecast problems Running the SOO/STRC WS Eta locally at the WFOs will serve to provide 1) numerical weather prediction (NWP) guidance to National Weather Service (NWS) and River Forecast Center (RFC) forecasters at temporal and spatial scales not available from operational data sources, 2) a powerful tool for studying local forecast problems and historically significant weather events, 3) an alternative to the configuration and physics of operational systems, 4) a means to develop and test new diagnostic forecast techniques, and 5) a method of training forecasters on NWP-related issues.
Q	Why would I want to run the workstation ETA instead of other mesoscale models such as MM5 or RAMS?
	The WS Eta is nearly identical to the operational Eta Model run at NCEP. It is a complete numerical weather prediction model with full physical parameterization to be used for both case study and real-time modeling experiments. A more detailed discussion of the Eta Model numerics and physics can be found at: http://meted.comet.ucar.edu/nwp/pcu2 The WS Eta is similar to other mesoscale models in terms of the complexity of model physics and numerics. However, there are two attributes that set the SOO/STRC workstation Eta package apart from the others: Ease of use Speed of model execution The SOO/STRC workstation Eta was developed to be a complete, easy-to-use numerical weather prediction package. Much of the time consuming task of setting up the model for real-time forecasting has been eliminated. In addition, full documentation is also provided to assist in the configuration and running of the model. An individual with little or no modeling and computer experience can have the model running in less than 1 hour. Of further consideration is that the WS Eta has been optimized by NCEP to perform very efficiently. This fact must be taken into consideration when selecting a model for your real-time forecasting needs. In a limited number of experiments with a similarly configured MM5, the workstation Eta demonstrated, on average, a 33% improvement in clock time for a 36h forecast. Moreover, the code is very scalable on multi-CPU systems with up to 90% performance gain going from 1->2 CPUs on a linux workstation.
Q	What Platforms does the WS Eta run on?
	The SOO/STRC workstation Eta has been tested under HPUX (10.20) and LINUX (Red hat 7.X kernel 2.4.X). However, there is no reason why it can't run on most platforms with minor porting.
Q	What type of PC do I need to run the workstation ETA?
	Please read the Computer Requirements section
Q	Do I need a compiler for the workstation ETA?
	No you don't need a compiler since binaries are provided for a variety of grid dimensions on the ftp server that you got the distribution.
Q	Do I have to use the same schemes used in the operational model? What are my options?
	The WS Eta includes an eta/sigma coordinate option, a non-hydrostatic option, and a choice of Kain-Fritsch or Betts-Miller-Janic cumulus schemes. It also has nesting capability.
Q	What is the format of the WS Eta output files?
	The raw model forecast files are a machine-dependent unformatted output; however, the post processor will generate output in either GRIB or BUFR format. Further post processing is available to GEMPAK or BUFKIT format.
Q	What is the format of the WS Eta initialization files?
	The following data sets in GRIB format are available to initialize a WS Eta model run: 104 ETA Model on a 91km domain 212 ETA Model on a 40km domain 221 ETA Model on a 32km domain TILE32 ETA Model 32km Tiled data TILE12 ETA Model 32km Tiled data AVN 1 degree Global AVN Model data set RNL 2.5 degree Reanalysis data WSE Grib files from a previous Ws Eta Model run