Radial Velocity

Shows relative motion in the atmosphere which can serve as an early indicator of rotation and the development of severe weather.

Features:

A color image of estimated radial velocity in the atmosphere

Generated in precipitation and clear air modes

Can detect rotation in the atmosphere

Measures the speed of the reflector in relation to the radar antenna

Negative sign = toward the radar antenna

Positive sign = away from the radar antenna

14 levels of velocity data on a scale from -64 to + 63 knots

2 levels are reserved for:

No observed velocity

Range folding (uncertain motion)

230km effective range of the radar

1km x 1 data resolution

4 (tilts) elevation angles:

Precipitation Mode  Clear Air Mode    
+0.50 degrees       +0.50 degrees     
+1.45 +2.40 +3.35   +1.50 +2.50       
                    +3.50

These elevation angles are planned for most NIDS sites. However, it is possible that the elevation angles used at some locations with unique geography will differ.

Benefits:

Provides early detection of severe weather development

-- Detection of mesocyclones, tornado vortex signatures, and gust fronts

-- Sees strong thunderstorm outflows, and boundary intersections (locus of future storm cell development)

Shows wind direction change at different distances and heights

Key Beneficiaries:

Operational meteorologists

Severe weather forecasters

Aviation meteorologists

Applications:

Early detection of severe weather

Mesoscale forecasting

Wind shift/inversion location

Severe weather hazards