Nexrad

GMI expert NEXRAD analysts use NEXRAD data to assist wind and airport developers with pre- and post-construction risk assessments for birds, especially migratory birds. GMI provides an analysis of NEXRAD data in order to characterize the bird migration temporal pattern at a proposed wind or airport site. GMI analyzes the previous three to five years of NEXRAD data for the spring and fall migration seasons.

In the U.S. the Doppler Weather Surveillance Radar (WSR-88D or NEXRAD) can be used to detect, quantify, and monitor biological targets in the atmosphere (e.g., bird migration, bird roosts, bat colonies, and concentrations of insects aloft).  NEXRAD can be used to obtain information on the temporal and geographical aspects of bird migration in addition to quantification of avian movements. The variability in the quantity of migration over a project area for several years, coupled with the occurrence of weather conditions that cause migrants to fly at low altitudes, can be used to estimate the number of occasions per season when collision events could theoretically occur.

NEXRAD analysis provides the developer with information on:

• Day-to-day variation in the amount of migration over the site
• Seasonal comparisons of the amount of migration
• Year-to-year variation in the amount of migration over the site

In addition, analysts use archived meteorological data to predict the number of occasions during migration periods when weather conditions force birds to fly at low altitude where collisions risk may increase.