Evaluating High-Resolution Model Data for Aviation Impacts Due to Cloud and Visibility for the San Francisco International Airport Part II

The Aviation Weather Testbed (AWT) 2018 Summer Experiment examined the use of multiple high-resolution data sets in a small region around the San Francisco International Airport (SFO). Airport operations are extremely sensitive to small areas of clouds impacting aircraft arrivals with the potential to affect planning across the National Airspace System (NAS).

The previous year’s experiment evaluated a single run of a super high resolution nest provided by the Met Office, with a better representation of orography and surface characteristics than NWS operational models to provide a realistic picture in the complex terrain. This year the Met Office provided multiple model runs, and NOAA Global Systems Division provided both a high resolution nest of the HRRR model and ensemble guidance from HRRR-E model.

The experiment design was based on daily forecast discussions and cloud clearing forecast times for SFO created operationally, issued by a joint partnership between the Oakland Center Weather Service Unit and the Monterey Weather Forecast Office. AWT participants were tasked with examining different high resolution forecasts, including the Met Office 330-m resolution nest, HRRR 750-m nest, HRRR-E ensemble guidance, along with high-resolution observations and satellite products to derive a forecast of cloud and visibility hazards for the SFO terminal area. This paper will discuss the unique challenges of forecasting cloud and visibility in the SFO terminal area, results from varying lead times of the 330-m Met Office model, 750-m HRRR, HRRR-E, and and the user evaluation of the experimental forecasts provided.