Meso-Gamma and Microscale Variability of Snowfall Rate Across an Airport Terminal Area

The Terminal Area Icing Weather Information for NextGen (TAIWIN) project, funded by the Federal Aviation Administration (FAA), has identified winter precipitation variability across the terminal area as a research area of interest. Winter precipitation variability has never been studied in-depth and different precipitation rates across the terminal area can have significant impacts on aviation operations. This is particularly true in instances where snow bands may move across the airport or if precipitation is only occurring over portions of the terminal area. While all winter precipitation types are of interest, the initial research has focused on snowfall variability, with future research planned to address freezing precipitation variability.

Current airport operations rely on point observations for determining snowfall rate over the terminal using a single precipitation gauge, but these observations are rarely indicative of the snowfall rate over the entire area. Assumptions of uniform snowfall rate can result in aircraft and runway de-icing and anti-icing fluids failing sooner than expected, allowing snowfall accumulation and/or ice accretion to build up on aircraft and runway surfaces. To address these issues, mesoscale and microscale spatial variability of snowfall rate needs to be understood. A study was developed using six Geonor T-200b precipitation gauges that were deployed over an area equivalent to an airport terminal area with distances between gauges varying from 0.1km to 9.8km. Data was collected from sixteen snowfall events during the 2015/16 winter season and statistical analyses were conducted on the one-minute snowfall rate measurements to determine the variability with distance between measurement locations. Results from the analysis of the events as well as possible correlations to other meteorological parameters will be discussed.

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.