5.3 Weather Radar

Prior to 1992 weather radar information from the National Weather Service (NWS) was limited in the western United States. This situation changed dramatically when the NWS, through a modernization effort in the 1992-1997 period, installed a network of very sophisticated 10 cm weather radars throughout the U.S. These sites are known as NEXRAD (Next Generation Radar) installations. Each installation cost on the order of $1,000,000. Figure 5.3 provides the array of these sites across the U.S. There are 160 NEXRAD sites now in service. NEXRAD radars provide information on precipitation intensities and wind speed and direction within the precipitation echoes. The radars step scan through 14 different elevation angles in a 5 minute period and a computer program integrates the stepped scans into a volume scan. Several very sophisticated algorithms then produce a large number of specialized displays and products from each volume scan. The maximum range for the detection of precipitation echoes is 143 miles from each site. The NWS provides all the necessary support for these systems; operation, calibration, spare parts and maintenance since the NEXRAD network is very important to NWS forecasting and public safety responsibilities, to many hydro-meteorological applications and to aviation safety. As a consequence these radars enjoy high priority support and resultant reliability. The Vandenberg AFB and the Los Angeles NEXRAD radars would provide good coverage of the proposed target area.