FAA Redefines Precipitation Terms

 - April 30, 2007, 10:37 AM

The FAA released official guidance last month regarding ATC’s ability to define and describe precipitation to pilots, including the terms controllers will use to describe the area of weather. With the advancement in radar technology, controllers can now determine the level of precipitation in the atmosphere, as opposed to simply where an area might be present. However, radar still won’t be able to determine the difference between ice, rain, snow, sleet or hail. To update pilots on the standardized terms, the FAA revised chapter 7, section 7-1-15 of the Aeronautical Information Manual. The terms, including associated inches of rainfall per hour, are: light (.01 to .1), moderate (.175 to .5), heavy (.5 to 2) and extreme (2 to 16+).