The National Weather Center offices in Norman, Oklahoma had a unique opportunity to test the latest weather radar technology as a tornado formed nearly over their heads in Norman during May 10, 2010, apparently slightly damaging the building and roof antennas.
Although there was tragedy and deaths related to the tornado outbreak, the silver lining was the incredible data set that was gathered with the new phased array radar (PAR) system that will lead towards better understanding of severe storms and tornadoes, and ultimately lead to earlier warning and preparedness for the public.
The existing network of NEXRAD radars (Next Generation Radar) across the United States consist of 159 WSR-88D systems (Weather Surveillance Radar 88 Doppler – the 88 representing 1988 when the technology was established). They are operated by the National Weather Service, an agency of NOAA (National Oceanic and Atmospheric Administration).
Phased Array Radar compared with NEXRAD WSR-88D
The phased array radar system has been used in the military for some time and is now being tested for use in weather applications. It scans much faster than the existing Doppler radar systems, as fast as 8 seconds for focused areas of interest and 20 – 30 seconds for a complete scan (the WSR-88D takes 5 minutes to perform a complete scan).
The existing WSR-88D scans a single beam of energy into a section of atmosphere, tilts up higher, scans another slice, tilts up, etc.. until that section of atmosphere is completed at which time it starts over and moves to the next section of atmosphere and repeats until a full volume scan is completed. This process takes about 5 minutes. The phased array system doesn’t physically tilt, but instead uses multiple beams, making it much faster. This will enable much more detailed tracking and rapid observation of changes that are occurring within a storm and may increase lead time of tornado warnings to 45 minutes.
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