Wednesday, 14 January 2004: 8:30 AM
NCEP's nonhydrostatic mesoscale model: Forecast guidance and transition to WRF
Efforts continue in applying the NMM to operational forecast problems. The model is being run daily with 8 km gridpoint spacing over three CONUS domains, specifically the western, central, and eastern U.S., at 0600 UTC, 1200 UTC, and 1800 UTC, respectively. An Alaskan run with 10 km resolution runs at 0000 UTC daily. Smaller 8 km resolution runs are made over Hawaii and Puerto Rico at both 0000 UTC and 1200 UTC. The operational 12 km Eta Model forecasts provide boundaries and most initial conditions for all of these so-called high resolution window runs. Specific forecast examples will be shown that contrast the guidance from NMM runs with that from the Eta Model. These examples include instances involving purely dynamical forcing as well as some in which topography places an important role.
As development of the NMM continues, a major effort has been underway to move the model into the WRF framework. Models and individual modules sharing the WRF framework are designed to make the exchange of components easier. This will greatly expedite the transfer of new packages between the research and operational communities. The NMM dynamic core and physics schemes currently running in NCEP's production suite as well as the necessary preprocessing and postprocessing jobs have been rewritten in order to bring them into the WRF infrastructure. After preliminary testing is carried out, the NMM will become part of an ensemble forecast system along with the NCAR eulerian mass model. The ensemble will replace the single deterministic forecasts now making up the hi-res window runs described above.