An operational Marine Stratus forecast system for San Francisco Intrenational Airport

The presence of low Marine Stratus in the approach to San Francisco International Airport (SFO) can reduce the air traffic arrival rate by a factor of two. A prototype Marine Stratus forecast system has been developed over the past eight years with support from the Federal Aviation Administration. This system forecasts the time that the Marine Stratus is expected to clear in the approach to SFO. Last year, the National Weather Service (NWS) agreed to adopt this system as an operational capability in the Monterey Weather Forecast Office. This report includes a description of the completed system (including a recently added probabilistic confidence factor), a discussion of its use by air traffic managers, and a discussion of its forecast skill.

Scientific innovations which have contributed to the success of these forecasts include: the enhancement of the COBEL column model for use with Marine Stratus forecasts; the extension of techniques for building statistical forecast models; an application of these statistical techniques to GOES satellite data; and a method for automatically measuring the height of the inversion base from Sodar data. Additional statistical models were developed: one based on regional NWS surface data and the other based on data from project sensors, which are installed at San Francisco and San Carlos Airports. A Consensus Forecast provides the best-estimate of the time of clearing, based on the four individual forecasts.