Rain or snow?



It's easy to look out the window and decide whether it's raining, snowing, or hailing, right? Well, not always—especially when the region of interest isn't directly outside your window. To help discern the difference, the National Oceanic and Atmospheric Administration (NOAA) has developed a laser beam device that differentiates between the precipitation types.

The laser weather identifier produces different signals when raindrops, snowflakes, or hailstones pass through the laser's beam, according to Ting-i Wang—until recently a scientist at NOAA's Environmental Research Laboratories in Boulder, Colo. These signature signals can be read by computer and integrated into present weather networks. ‘It can eliminate human error or negligence, and can be cost effective by constantly observing and monitoring the weather,’ Wang noted. Wang and his colleagues are developing several of the laser instruments for evaluation by NOAA's National Weather Service. The first of these is scheduled to be installed in 1984.