The Spring 2008 National Weather Radar Testbed (NWRT) Phased Array Radar Demonstration begins April 14, 2008 and will run through June 15, 2008. A primary objective of the experiment will be to have forecasters from National Weather Service (NWS) forecast offices across the nation evaluate Phased Array Radar (PAR) data in real-time to investigate the potential operational benefits of PAR technology.

The hands-on evaluation by NWS forecasters will take place from April 28, 2008 through 6 June 2008, when storms are located in central Oklahoma. Forecasters will be asked to perform real­time radar analysis of storms and issue experimental severe weather warnings using NSSL’s Warning Decision Support System – Integrated Information. A NSSL research meteorologist will be available to operate the PAR and serve as an information resource. After operations, forecasters will be asked to fill out a survey to evaluate the strengths and limitations of PAR data in their analysis of severe storms, how characteristics of PAR scanning strategies affect their understanding of severe storms, how using PAR data to make warning decisions impacts their warning decision-making, and how PAR data may be a benefit to operational responsibilities for the public.

In preparation for the experiment NSSL researchers tested new software and scan strategies during March and the first part of April, 2008. Data was collected on several long-lived supercells, which produced hail, strong winds, and a few short-lived tornadoes.

Background: The rapid­scan, multi­function capabilities of Phased-array Radar (PAR) make this technology an attractive option to replace the almost 20-year old WSR-88D. The National Weather Radar Testbed Phased Array Radar (NWRT PAR) located in Norman, Oklahoma, samples storms from a 9.38­cm, single­faced, PAR antenna. The PAR supports adaptable scanning strategies and volumetrically scans storms in time scales of seconds instead of several minutes. Such high­temporal sampling provides an unprecedented opportunity to improve understanding of rapidly evolving weather phenomena, explore the potential to extend warning lead-time for severe weather, and to investigate the potential benefits of PAR to forecast operations.

Significance: This evaluation of the potential operational utility of PAR is crucial to determine its suitability as a replacement technology for the WSR­88D.