NEXRAD Products

• Base Reflectivity (NOR, NAR, N1R, NBR, N2R, N3R/19)
  A display of echo intensity measured in dBZ. Scientists use these products to detect precipitation, evaluate storm structure, locate boundaries, and determine hail potential. Four or six of the lowest elevations angles are available, depending on the scanning mode of the Radar. Sixteen possible data levels are also available.
• Digital Base Reflectivity (NOQ, NAQ, N1Q, NBQ, N2Q, N3Q/94)
  The same as N*R products defined above except data values are actual reflectivity values instead of categories.
• Base Velocity (NOW/25, NOV, N1V, N2V, N3V/27)
  A measure of the radial component of the wind either toward the radar (negative values) or away from the radar (positive values). Cool colors (green) represent negative values and warm colors (red) represent positive values. Scientists use these products to estimate wind speed and direction, locate boundaries, locate severe weather signatures, and identify suspected areas of turbulence.
• Digital Base Velocity (NOU, NAU, N1U, NBU, N2U, N3U/99)
  The same as N*V products defined above except data values are actual velocity values instead of categories.
• Storm Relative Velocity (NOS, N1S, N2S, N3S/56)
  When the motion of storms is subtracted from the wind field, the result is a picture of the wind as if the storms were stationary. Color indices are the same as base velocity. Comparing the storm relative motion image with base velocity image helps identify the rotating storm.
• Base Spectrum Width (NSP/28, NSW/30)
  A measure of velocity dispersion within the radar sample volume. The primary use of this product is to estimate turbulence associated with mesocyclones and boundaries.
• Composite Reflectivity (NCO/36, NCR/37, NCZ/38)
  Composite Reflectivity is a display of maximum reflectivity for the total volume within the range of the radar. These products reveal the highest reflectivities in all echoes, examine storm structure features, and determine the intensity of storms.
• Low/Mid/High Layer Composite Reflectivity (NLL/65, NML/66, NHL/90)
  Low/Mid/High Layer Composite Reflectivity is a display of maximum reflectivity for three different height ranges within the volume scan. Use this product to reveal the highest reflectivities in all echoes, examine storm structure features, and determine the intensity of storms.
• Vertically Integrated Liquid (NVL/57)
  The water content of a 2.2 x 2.2 nautical mile (nm) column of air, which is color-coded and plotted on a 124-nm map. This product is an effective hail indicator, used to locate most significant storms, and to identify areas of heavy rainfall.
• Echo Tops (NET/41)
  An image of the echo top heights color-coded in user-defined increments. Scientists use this product for a quick estimation of the most intense convection and higher echo tops, as an aid in identification of storm structure features, and for pilot briefing purposes.
• VAD Wind Profile (NVW/48)
  A graphic display of wind barbs plotted on a height staff in 500-ft. or 1,000-ft. increments. The current (far right) and up to 10 previous plots may be displayed simultaneously. This product is an excellent tool for meteorologists in weather forecasting, severe weather, and aviation.
• Differential Reflectivity (ZDR) (N0X, N1X, N2X, N3X/159) (Dual-Pol. only)
  Differential Reflectivity values are measurements related to the returned energy difference between the vertical and horizontal radar pulses. Large positive values indicate that targets are generally much larger horizontally than vertically. Values near zero indicate the targets are generally spherical. Negative values indicate targets are larger in the vertical than in the horizontal. The four lowest elevation angles are available.
• Correlation Coefficient (CC) (N0C, N1C, N2C, N3C/161) (Dual-Pol. only)
  Correlation Coefficient values are measurements related to the similarity between the behaviors of the horizontally and vertically polarized pulses and how they are behaving within a pulse volume. Values between 0.95 and 1.0 indicate near uniformity in pulse behavior. Meteorological targets with complex shapes, or with a large degree of variety, will generally have values between 0.85 and 0.95. Biological targets, anthropogenic targets, and ground clutter tend to cause very different behaviors between the pulses, resulting in values less than 0.9 (and often less than 0.7). The four lowest elevation angles are available.
• Specific Differential Phase (KDP) (N0K, N1K, N2K, N3K/163) (Dual-Pol. only)
  Specific Differential Phase is a measurement of difference between the horizontal and vertical pulse phase changes as they travel through the atmosphere. Interpreting Specific Differential Phase (KDP) can be very difficult. Its primary use involves detecting areas of heavy rain. KDP values are largest when going through areas dominated by large raindrops. In some cases, regions with high KDP values may also contain melting hail. The four lowest elevation angles are available.
• Hydrometeor Classification (HC) (N0H, N1H, N2H, N3H/165 (Dual-Pol. only)
  Hydrometeor Classification is a computer algorithm output that determines the most likely classification of the targets in the radar volume. The product displays the predefined categories that were most likely the cause of the radar echo at that location. The four lowest elevation angles are available.
• Melting Layer (ML) (N0M, N1M, N2M, N3M/166) (Dual-Pol. only)
  Melting Layer is a computer algorithm output that determines where the radar beam intersects the level of the atmosphere where frozen precipitation starts melting. This product provides users with information on whether precipitation should generally be frozen, melting, or liquid in a particular area. This product is generated on each elevation angle that the radar scans and can be particularly useful for tracking icing conditions above the surface. It may have problems when surface temperatures are below freezing, in mountainous locations, or when data needed for the algorithm is limited. When radar echoes are insufficient for the algorithm to work properly, it will default to the freezing level data entered manually or from computer models.
• Hybrid Hydrometeor Classification (HHC/177) (Dual-Pol. only)
  The Hybrid Hydrometeor Classification is obtained from the best/lowest available scan at each location. This product serves as input to the dual-polarization precipitation estimation products.

Precipitation Products