Coming soon to a weather service office near you

Dual-Polar radar system. (Courtesy: NOAA)

By Dave

CHARLESTON, S.C. (WCIV) -- Technology advances quickly. Take for instance, iPads or iPhones.{} On average the new model comes out every eight months to a year, making older models a bit outdated.

Let's just say the same goes for weather forecasting. Twenty years is way past time to update.

"The National Weather Service WSR 88-D radar for the Charleston area was commissioned in Grays, S.C., northern Jasper County in 1992," said Steve Taylor,{} a meteorologist with the Charleston office of the National Weather Service.

The current radar output is serviceable and continues to detect rain, but a newer more advanced dual-polarization radar technology is available and will be installed later this year.

"The entire United States network of 160 radar sites, including Alaska, Hawaii, Puerto Rico and Guam will be upgraded by early 2013 at a cost of about $50 million," Taylor said.

One of the limitations of the current radar is it cannot detect what a specific object is when the beam makes contact. It may be a raindrop or a snowflake, possibly even "biologics," such as a bird or insect. The radar can only tell whether there is a dense or a sparse concentration of airborne objects, along with their motion.

"The Dual Pole radar transmits and receives data in both the horizontal and vertical plane, providing a two dimensional picture of what type of precipitation is actually out there. This will give us a higher confidence level to know if rain, hail, or in an unlikely case in the Charleston area, snow is falling out of a cloud," Taylor said.

Unfortunately the radar will not give us a better indication of when a tornado forms. The technology has not advanced that far yet, but it will likely show when a tornado reaches the ground.

"Dual-polarization radar technology can detect and identify the presence of tornado debris, giving the forecaster a high degree of confidence that a damaging tornado is on the ground," Taylor said.

The switch will take about two weeks. A team will replace some of the components in the current radar site, meaning we will depend on surrounding weather service offices to supply the Lowcountry with radar coverage.

"The upgrade will take place when the surrounding Weather Service offices in the Southeast are fully operational, and in a typically climatological quiet time of year," Taylor said.

The Charleston dual-polarization upgrade is slated for November 5-18, after severe thunderstorm season and the heart of hurricane season.

* Before joining ABC News 4, Meteorologist Dave Williams was just up the road at WBTW in Myrtle Beach. Armed with a wealth of experience forecasting the weather in the Palmetto State, Dave is a member of the National Weather Association, American Meteorological Society, and holds a Seal of Approval from the NWA. Click here for more info.

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