Sacramento WRF-NMM Information

• We use a SIGMA vertical coordinate with 45 levels.
• 12-km NCEP Operational grib 2 NAM tiles are used for the lateral boundary conditions to initialize the model.
• We use the 0.5 degree High Resolution Sea Surface Temperature(SST) dataset.
• Betts-Miller-Janic cumulus (convective) parametrization scheme is used (we have the option to use Kain-Fritsch (KF), Grell-Devenyi ensemble, Simplified Arakawa-Schubert scheme or no scheme).
• The model uses Ferrier microphysics and Mellor-Yamada- Janjic Boundary Layer scheme with a 5 min time step.
• We run the model non-hydrostatically at a 12 second time step.
• The model output domain is a 68x146 grid centered at 39.2N and 121.8W.
• Output is available at 1-hr forecast increments to 48-hrs and is usually available by 0755 UTC (00z run), 1355 UTC (06z run), 1955 UTC (12z run), and 0155 UTC (18z run).
• The model is compiled on an AMD 64 4600+ workstation with 2 GB RAM running SuSE Linux 10.0.
• A 1200 UTC model run starts the download of boundary conditions at 1355 UTC and completes the download around 1440 UTC. Model begins compiling and usually takes around 3.5 hrs to complete. There is then another hour of post processing. The completed model cycle usually occurs by 1930 UTC.
• We use GEMPAK 5.6H to create the graphics to post to the web page.
• Final Web Graphics are posted at 02 UTC, 08 UTC, 14 UTC, and 20 UTC.

We expect to use the model qualitatively to help refine phenomena related to terrain such as temperature, winds and orographically forced precipitation. This model should give some clues about how complex terrain can affect local weather in northern California.

Webmaster
US Dept of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
Sacramento Weather Forecast Office

Sacramento, CA

Tel: (916) 979-3051