Quality Assessment of the Real-Time Mesoscale Analysis (RTMA) for Aviation

In recent years, the Federal Aviation Administration (FAA) and airlines across the United States have considered several ways to mitigate the effects of costly flight delays, cancellations, and diversions that stem from missing METAR observations. These observations are required by the FAA in order to ensure the safe operation of aircraft and include elements such as altimeter setting, ceiling, and visibility. Owing to these costly delays and cancellations, the FAA worked with the Environmental Modeling Center of the National Weather Service to provide temperature data interpolated from the Real-Time Mesoscale Analysis (RTMA) at airport locations across the United States (i.e., airport weather status) to serve in lieu of missing temperature reports. This effort was accomplished in 2015. Since then, there has been strong interest in evaluating if other analysis parameters from the RTMA may be used in a similar fashion. The RTMA is an hourly, two-dimensional variational analysis system that assimilates METAR observations, mesonet data, satellite-derived winds, scatterometer winds, and buoy and ship data to create gridded analyses of sensible weather elements.

The purpose of this work is to determine if the airport weather status list can be expanded to include other sensible weather elements, including ceiling, visibility, 10 m wind, 10 m wind gust, specific humidity, and surface pressure. Data denial experiments are performed to characterize how much quality is lost in the analysis at airports of interest when their respective observations are denied. Analyses are generated for a two-week period for each season, beginning with July 2017. The quality of ceiling and visibility analyses are considered using performance diagrams and boxplots, with observations stratified by flight category. Boxplots, histograms, and two-dimensional station maps are used to assess the quality of continuous surface variables (e.g., temperature, pressure, and specific humidity).

Disclaimer: This research is in response to requirements and funding by the Federal Aviation Administration (FAA). The views expressed are those of the authors and do not necessarily represent the official policy or position of the FAA.