NEXRAD Radar - WTOC-TV: Savannah, Beaufort, SC, News, Weather & Sports

NEXRAD Radar

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National Weather Service Radar from Charleston, SC.  Radar located in Grays, 10 miles north of Ridgeland.
Information about the NEXRAD Radar Products

This is the NEXRAD WSR 88D Doppler radar operated by the National Weather Service, Charleston, SC. The radar is located in Jasper County, SC in Grays, which is about 10 miles north of Ridgeland. Data from this radar is updated once every 5 minutes. This is only a portion of the total data from the radar these maps centered on the WTOC viewing area, which is mostly the southern half of the radar view.

Available Products:

Base Reflectivity:
This is your basic radar image showing the reflected values of the targets. The green would indicate light precipitation with the color ramping up to red indicating heavy precipitation. However, there are two modes of operation with the product and they are “Precipitation mode”, and “Clear air mode” .

Clear Air Mode:
In this mode, the radar is in its most sensitive operation. This mode has the slowest antenna rotation rate which permits the radar to sample a given volume of the atmosphere longer. This increased sampling increases the radar's sensitivity and ability to detect smaller objects in the atmosphere than in precipitation mode. A lot of what you will see in clear air mode will be airborne dust and particulate matter. Also, snow does not reflect energy sent from the radar very well. Therefore, clear air mode will occasionally be used for the detection of light snow. In clear air mode, the radar products update every 10 minutes.

Precipitation Mode
When rain is occurring, the radar does not need to be as sensitive as in clear air mode as rain provides plenty of returning signals. In Precipitation Mode, the radar products update every 6 minutes.

Radial Velocity:
This is the velocity of the precipitation either toward or away from the radar (in a radial direction). No information about the strength of the precipitation is given. The green through blue color indicate precipitation targets moving toward the radar while the yellow through red indicated targets moving away.

Vertically Integrated Liquid Water (VIL)
VIL is the amount of liquid water that the radar detects in a vertical column of the atmosphere for an area of precipitation. High values are associated with heavy rain or hail

Cloud Tops
The Echo Tops image shows the maximum height of precipitation echoes. The radar will not report echo tops below 5,000 feet or above 70,000 feet, and will only report those tops that are at a reflectivity of 18.5 dBZ or higher. In addition, the radar will not be able to see the tops of some storms very close to the radar.

Velocity Azimuth Display (VAD) Wind Profile
Coming Soon ... The VAD Wind Profile image presents snapshots of the horizontal winds blowing at different altitudes above the radar. These wind profiles will be spaced 6 to 10 minutes apart in time, with the most recent snapshot at the far right. If there is no precipitation above the radar to bounce off, a "ND" (Non-Detection) value will be plotted.

More Information:
A detailed discussion of these products and all other NEXRAD products can be found at: The Weather Underground of the University of Michigan


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