For all fellow weather geeks that dive in beyond just a glance of the radar and into what velocity information is returning, the VCP the radar is running in, and stand amazed about how a volume scan looks in 3D, then I have news for you!
According to the NWS Radar Operations Center, a modified VCP is in the works. By the way, if you’ve ever wondered VCP stands for, it’s Volume Coverage Pattern and is the “mode” government radars run in during various forms of weather.
At present, NEXRAD operators have a selection of 9 VCP’s to choose from depending on if storms exist in the radar’s coverage area or if there clear blue skies above.
The proposal being considered by weather service higher-ups is a re-working of VCPs 12 and 212. Currently 12 and 212 are used for detailed severe weather tracking with tilts, or elevations the radar is scanning at, ranging from 0.5 degrees to 19.5 degrees.
The “Supplemental Adaptive Intra-Volume Low-Level Scan,” or SAILS for short, would see three additional 0.5 degree tilt scans added at intervals to VCP 12/212. This would greatly enhance long range radar coverage when seconds matter in severe weather.
For the weather layman, the NEXRADs scan on a series of tilts. The higher the radar antenna is pointed, the more restricted widespread coverage becomes. This is done to provide radar users a “volume” scan which when placed in to certain computer programs, shows meteorologists a detailed 3D view of a storm.
Such a product is useful when identifying storm structure, however when tracking a tornadic storm, a basic 0.5 degree radar scan is the most useful for showing whats happening as close to the Earth’s surface as possible.
Adding three more 0.5 degree scans comes at a price of time; expanding the total time of the volume scan by 35 seconds.
By far, more positives will come from having additional “looks” at the base level for radar scans which will further enhance the issuing of warnings and other potentially life saving information.
The concept is still being looked at and will more than likely under go more changes before becoming active across the network of 150+ NEXRAD units in the United States and it’s territories.
I’l continue to follow this enhancement’s progress and when SAILS could be added to the KHTX NEXRAD.