EVALUATION OF DGEX (DOWNSCALED GFS WITH ETA EXTENSION) GRIDS

NCEP/EMC is partnering with the IFPS Science Steering Team (ISST) to provide high resolution extended-range grids for field evaluation. These grids are produced by running the 12-km 60 vertical levels Eta model from forecast hour 78 to forecast hour 192 using boundary conditions from the previous cycle of the GFS over a near CONUS domain. The output of this process results in the Downscaled GFS with Eta Extension (DGEX) grids.

The DGEX evaluation period will commence 0000 UTC March 15, 2004, and end with the 1800 UTC April 15, 2004. The target operational implementation date is in June 2004. During the evaluation period the DGEX will be run off of EMC’s parallel experimental 12-km Eta run, which is only available for the 0000 UTC cycle; grids will be available for hours 84 through 192 inclusive. The nominal delivery time to the field of the CONUS DGEX run during the evaluation period will be approximately 1200 UTC. If the parallel Eta-12 system is implemented by NCEP Central Operations during March, 1200 UTC forecasts may also be produced, and delivery times will improve. See the associated PowerPoint presentation for additional details.

Every effort is being made by EMC to support OCONUS offices in the Alaska Region during the evaluation period. Additional testing is still required before a final determination can be made. The goal is to run once per day off the 0000 UTC cycle with the Alaska Region run complete by approximately 1500 UTC.

Two WFOs per CONUS region are needed to evaluate DGEX grids within GFE and AWIPS. It is preferred that these WFOs be selected to maximize the potential of capturing meteorological diversities within your region. It would also be helpful, although not mandatory, for the WFOs within your region to be adjacent to each other to help address DGEX impact on collaboration. Each office must currently be running the LDM and be familiar with ingesting local model data.

Instructions on how to ingest DGEX grids, access the grids via GFE, and display them within AWIPS will be made available from Kirby Cook (WR). A baseline set of SmartInit scripts is being developed by Tim Barker and will be distributed along with the other support files by Kirby.

It is important to note that during the evaluation period DGEX will be vulnerable to delays and outages. Each participating WFO will be asked to provide an evaluation centered on usability of output - including accuracy issues and impact on workload.

Cursory evaluation of DGEX output can also be conducted outside of GFE by any WFO via the web pages:

http://wwwt.emc.ncep.noaa.gov/mmb/mmbpll/etapll8day/(CONUS)

http://wwwt.emc.ncep.noaa.gov/mmb/mmbpll/etapll8day.ak/ (Alaska)

NCEP HPC will also evaluate DGEX output.

Please provide a list of participating WFOs using GFE by COB Feb 27, 2004, to ISST team lead Brad Colman or Peter Manousos. Questions on the evaluation procedure can also be sent to Brad Colman and Peter Manousos.