We've heard a lot about wind shear lately. What's being done to protect planes from this dangerous weather phenomenon?
For the last ten years, scientist and engineers at NCAR/RAP have studied wind shear and developed wind shear warning systems for airports. Denver's Stapleton Airport has been the site for testing and demonstrating these new systems. A network of surface wind sensors coupled with powerful Doppler radars makes up the automatic windshear warning system. The FAA will begin implementing these systems at 45 airports nationwide beginning in 1993.
Contact: Bill Mahoney (303-497-8426)
Are we able to predict thunderstorms and the severe weather (tornadoes, hail, heavy rain and strong winds) associated with them?
The new sensitive Doppler radars under installation across much of the country are capable of providing data for the detection of severe thunderstorms and some of the associated severe weather. New radars have also improved the ability to predict the movement and evolution of such storms. It is still difficult, though, to accurately forecast thunderstorms, particularly on summer afternoons in Colorado when the atmosphere is typically near "neutral". This means that relatively small details in the temperature and humidity can make all the difference in determining when and where thunderstorms form. Often these details are small enough that they are hidden in our normal weather observations and missed.
Contacts: Jim Wilson (303-497-8818); Mike Dixon (303-497-8440);
Peter Neilley (303-497-8446); Ed Brandes (303-497-8487)
Why are airplanes being de-iced more frequently this winter than in the past?
A new FAA rule has been put into effect requiring all airlines to use a holdover timetable to determine the time allowed between de-icing and takeoff. This new rule was prompted by the crash of a USAIR aircraft at LaGuardia in March of 1992 that was due to icing on the wing. In order to determine the holdover times accurately, however, timely knowledge of the snowfall rates and surface weather is needed. NCAR/RAP is working on methods to accurately depict snowfall and weather conditions at airports, using radars, snowgauges, and surface weather stations. These techniques were tested last winter at Stapleton airport and will be tested at other airports during upcoming winters.
Contact: Roy Rasmussen (303-497-8430)
Icing continues to be one of the primary causes of aviation accidents. What's being done to improve the forecasting of the weather that causes ice to build up on aircraft?
The conditions which create hazardous icing conditions are complex and not yet well understood. Progress is being made on a number of fronts, however. Research aircraft are taking measurements of critical atmospheric factors that lead to icing, such as supercooled liquid water, air temperature and the size of liquid droplets. Scientists and engineers are using new research radars to pinpoint regions of liquid water and ice in clouds and measure water drops and ice crystals. Numerical models are also being developed to provide guidance to forecasters as to when and where icing is likely to occur.
Contacts: Marcia Politovich (303-497-8449); Jothiram Vivekanandan (303-497-8402)
How does the weather in Denver affect whether your flight from Los Angeles to Boston will be on time?
The nationwide flow of air traffic is centrally controlled by the FAA to maximize efficiency. Traffic management coordinators at major airports determine current airport capacity based on local weather and airport configuration and communicate this information to FAA Central Flow. Engineers at RAP are using knowledge engineering technology to model the decision making which determines individual airport capacity. Combined with airport terminal weather forecasts, this will provide a valuable tool to FAA Central Flow for anticipating and responding to weather-based changes in airport capacity.
Contact: Cory Morse (303-497-8429)
As new means of compiling aviation weather hazard information are developed, how do we ensure that they're put to use to improve aviation safety?
Scientists and engineers at RAP are part of the multi-billion-dollar update of the national aviation weather system, providing new weather products that will have a profound impact on aviation safety and users' ability to plan flight operations more efficiently. Current efforts are focused on how best to provide these products to pilots and other users of the national air space in order to minimize the interpretation needed to make decisions. Using state-of-the-art graphics computers and data uplink/downlink strategies, researchers are exploring a variety of information delivery modes to make sure that users get the information they need, when they need it, and in a format that is useful to them.
Contact: Tenny Lindholm (303-497-8448)