Science: Weather Radar Net

To weathermen, radar has been the biggest boon their science has known since the barometer. Without radar, weather forecasters had to depend on reports from observation stations, which are always too few, and often slow to arrive. With radar, they can actually watch the approach of storm clouds. Many a weather or storm disaster might have been averted or minimized if proper radars had been on the job to flash a timely warning.

The U.S. Weather Bureau (traditionally starved, by Congress) has only a few hand-me-down military radars. But this week the Bureau announced a $3,800,000 contract with Raytheon Manufacturing Co. for 39 complete radar units specially designed for its specialized needs.

Weather radar works by sending out pulses of radio waves which are reflected by raindrops, hailstones and other precipitation particles. Shorter waves rebound from the tiny drops of moisture of a cloud's surface. The longer wave bands penetrate clouds like X rays, show only the inner core (if any) of heavy rain or hail.— Thus, by varying wave bands and pulse lengths, the new weather radars can look at a cloud as a whole or can look deeply into it, or even through it. They can measure accurately a cloud's altitude —a matter of critical importance, since the highest storm clouds are usually the most violent and the most likely to produce cloudbursts and tornadoes. Through their ability to see raindrops before they fall, they will enable weathermen to predict flash floods; when clouds are observed dropping heavy rain on a mountain watershed, the people in the valley below can be warned to take to the hills.

Delivery of the radars will begin in 1958. The Weather Bureau will use the first ones to track hurricanes up the East Coast (now hazardously done by airplanes) and to watch for dangerous thunderheads in the tornado belt. Eventually the Weather Bureau hopes the gaps will be filled in and all the radars tied together in a nationwide network that will provide earlier and better weather forewarnings for farmers, sailors and householders from Spokane to Bangor.