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WFO Greenville-Spartanburg, SC

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NWS Greenville-Spartanburg, SC
Dual Polarization Radar Upgrade

Greenville-Spartanburg Weather Radar Dual Polarization Installation is Complete

The National Weather Service Forecast Office in Greenville Spartanburg South Carolina, which serves more than 4.8 million people in 46 counties across the western Carolinas and northeast Georgia, has upgraded its Doppler radar with dual polarization technology. The new technology is the most significant enhancement made to the nation's radar network since Doppler radar was first installed more than 20 years ago.

Meteorologists will use the new radar data to improve weather monitoring for winter storms, excessive rainfall rates, hail, and tornado debris. Ultimately, this upgrade is one more step in our efforts to build a weather ready nation. Enhanced forecaster confidence in radar weather observations will improve public response to weather warnings and improve readiness.

What will dual-polarization do?

Conventional single-polarimetric NWS radars provide information on precipitation intensity and movement. Dual-polarization technology adds the ability to sense the size and shape of objects in the atmosphere. This will enable meteorologists to make numerous advances in forecasting and warning capabilities:
  • Improved accuracy in identifying precipitation types. This will lead to more accurate winter weather forecasts, especially during times of mixed and icy precipitation.
  • Improved precipitation estimates. This will lead to more accurate river forecasts and flash flood warnings.
  • Improved detection of non-precipitation targets. This will allow forecasters to focus on real precipitation radar targets.
  • Improved hail detection. The new radar products will lead to increased confidence in the presence and size of hail in strong to severe thunderstorms.
  • The ability to detect lofted tornado debris. Although this will not directly lead to improvements in tornado warnings, it will provide higher confidence of a tornado's presence and track when significant damage is occurring. This could be especially benefical at night, when tornadoes are difficult to see. A caveat though; tornadoes will need to be close to the radar to sample the lofted debris, or a far tornado will need to be strong to be able to lift debris to the altitude that the radar will be sampling it.

How does it work?

Conventional Doppler radar transmits and receives horizontally polarized radio wave pulses. Thus, the radar is only able to measure the horizontal dimension of atmospheric targets.

Dual-polarization Doppler radar transmits and receives pulses that are polarized both horizontally and vertically. Thus, the radar is able to measure the horizontal and vertical dimensions of atmospheric targets.

By comparing the power returned to the radar from the differing horizontal and vertical pulses, a great deal of information can be generated with respect to the size and shape of targets in the atmosphere.

Animation of Single Vs. Dual Polarization

Current NWS Doppler Radar

Dual-polarimetric radar

Where can I learn more?

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National Weather Service
Weather Forecast Office Greenville-Spartanburg
GSP International Airport
1549 GSP Drive
Greer, SC 29651
(864) 848-3859
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Page last modified: June 29, 2012

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