Winter Weather Research

PDT research has resulted in a stand-alone, integrated display system that uses all the following as principal sources of data: regional area Doppler radars; surface weather stations; and snow gauges located on and near the airport to determine precipitation type, temperature, wind speed and direction, and the amount of water in the snow. The WSDDM system integrates these parameters and provides critical deicing guidance, such as precipitation type, temperature and wind conditions, liquid snowfall equivalent, and a 30-minute forecast of precipitation intensity and movement so that near real-time aircraft deicing decisions can be made. These decisions center on when to de-ice, how often to de-ice, and the best type of deicing fluid to apply.

Benefits to the aviation community:

• Weather information important to safety is provided to decision makers such as pilots, air traffic controllers, ground service personnel, dispatchers, and airport managers
• Accurate and timely forecasts improve efficiency of deicing operations, reducing ground delays
• More efficient use of deicing fluid for a cleaner environment results in less run-off waste and savings in clean-up operations
• More efficient runway plowing operations reduce arrival and departure delays

WSDDM research determined that the accurate measurement of liquid equivalent snowfall rate by snowgauges is one of the most important factors in determining holdover times of deicing fluids (time until a fluid fails to protect against ice build-up). Reported visibility during five of the last ten accidents mentioned above was light to moderate, although snowgauges at the airports indicated high liquid equivalent precipitation rates. Previously, airlines relied on pilot and National Weather Service estimates of snow intensity, both of which are based on prevailing visibility, not liquid equivalent. However, WSDDM research showed that large dry snowflakes, which reduce visibility the most, are less of a threat than small, wet flakes. This important finding increased awareness that visibility alone can be misleading for deicing aircraft decisions. An early benefit of WSDDM research was that USAirways, Delta, and United Airlines incorporated this finding into their winter training manuals for pilots.

Below are the links to sub articles on Aviation Digital Data Service:

Ceiling and Visibility
Turbulence
Convective Weather
Winter Weather Research
In-Flight Icing
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