The Bay Area Wind Model
The Bay Area Wind Model is a diagnostic wind model used to aid our meteorologists to better understand and forecast the mesoscale processes which affect the onset and clearing times of marine stratus over San Francisco Bay. Marine stratus in the approach zone into San Francisco International Airport, SFO, is a significant problem for arriving aircraft and for the FAA because of the close proximity of the landing runways. The result of low clouds at SFO is that the arrival capacity of the airport is cut in half of that of otherwise clear weather conditions.
The model is run hourly and displays a vector plot of all the primary and supplemental wind reports available to the CWSU. In addition to the actual winds, the model plots stream flow vectors over SFO Bay based on an interpolated scheme. The scheme is guided by the critical dividing streamline concept in its treatment of atmospheric stability, terrain induced vertical motion, and by mass conservation constraints. A detailed discussion of the model and its application is available from the following AMS article. "Applications of a Diagnostic Wind Model to Stratus Forecasting for Aircraft Operations in the San Francisco Bay Region", by W Strach, F Ludwig, D Sinton and A Becker, 7th Conference on Aviation, Range, and Aerospace Meteorology, Feb. 1997, Long Beach, CA.
EXAMPLE OF WIND MODEL DISPLAY
CLICK HERE FOR CURRENT WIND MODEL DISPLAY
The model output is run and displayed each hour at the CWSU. An example is shown above. The same data set is made available to the U.S. Geological Survey who in turn generates a real time plot on the Internet.
Stanford Research Institute originally developed the wind model for the U. S. Army. San Jose State University adapted the model to the San Francisco Bay Region for the National Weather Service. The work was accomplished under a University Center for Atmospheric Research, (UCAR), sponsored Cooperative Meteorological Education and Training (COMET) project.