Upgrade To NWS Radar Will Provide Faster Storm Scans

 

A recent upgrade to the National Weather Service radar will allow forecasters to receive radar data as much as 25% quicker. The capability of quicker data retrieval will come from the radar's ability to recognize precipitation free regions and abort a scan of that area due to the lack of precipitation. The result will be faster radar image dissemination that could lead to advanced warning lead time. Along with the advanced lead time, the upgrade will reduce wear and maintenance costs for the radar. The upgrade to the radar is called AVSET (Automated Volume Scan Evaluation and Termination).

Reference the image below to better understand how AVSET works. We will use a thunderstorm for example. The radar works by rotating 360 degrees at different elevations above the surface. This helps forecasters to sample a storm from the bottom to the top. If a storm is far away from the radar, a lot of the scans can overshoot the top of the storm because the radar beam height rises the farther from the radar it gets. AVSET eliminates these extra scans (Big Blue X in the image below) above the storm top and saves time taken to develop the image! The average scan used to take about 4 minutes and 30 seconds under the fastest scanning conditions. With AVSET, the time can be cut to 3 minutes and 30 seconds, roughly 25% less! The red scan lines in this example are needless and the scan will be aborted once the top of the storm has been sampled.

AVSET will not always be implemented, however. Consider the picture below. If there are storms close to the radar (red arrow in image below) as well as storms far away, all of the elevations scans will need to be used. In this scenario AVSET benefits will be negligible.



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