The lowest elevation angle scanned by all radars in the Weather Surveillance Radar–1988 Doppler (WSR-88D) network is 0.5 deg. Users of Terminal Doppler Weather Radars (TDWRs) and research Doppler radars find that scanning at 0.0 deg reveals the presence of boundaries of forecasting significance that frequently are not evident at 0.5 deg elevation angles. Furthermore, forecasters who prepare warnings based on mountaintop WSR-88D measurements frequently find that the radar overshoots hazardous weather phenomena that threaten the surrounding populace. Simulations indicate that the use of negative elevation angles at mountaintop sites would permit the detection of hazardous weather and would greatly improve the accuracy of surface rainfall and snowfall estimates.

With a basic need for WSR-88Ds to scan at lower elevation angles, the WSR-88D Radar Operations Center—in collaboration with National Weather Service Forecast Offices, National Severe Storms Laboratory, Department of Defense, and Federal Aviation Administration—is proposing that each WSR-88D collect data at elevation angles that are best suited for its locale. To test the operational feasibility of lowering elevation angles, a two-year field test is being proposed for six WSR-88Ds, three located on mountaintops and three located on relatively flat terrain. The test plan currently is being evaluated at various administrative levels within the National Weather Service. A status report on the plan will be presented at the meeting.