The National Weather Service (NWS) is undergoing a major modernization program to improve the quality and reliability of its products and services. The technological keystone of this modernization is the new Doppler weather surveillance radar (Model WSR-88D). The WSR-88D excels in dectecting the severe weather events that threaten life and property, from early detection of damaging winds to estimating rainfall amounts for use in river and flood forecasting. Most important, WSR-88D can increase advance warning - and the specificity of such warnings - for shortlived, often catastrophic events such as tornados, downbursts and flash floods.

Velocity (click on image to see full size image)

Using Doppler technology, the WSR-88D calculates both the speed and direction of motion of severe storms. By providing data on the wind patterns within developing storms, the new WSR-88D identifies the conditions leading to severe weather such as tornadoes. This means earlier detection of the precursors to tornadoes, as well as data on the direction and speed of tornadoes once they form.

Velocity (click on image to see full size image)

In a cooperative effort with the Department of Defense and the Federal Aviation Administration, the NWS anticipates a total of nearly 160 radars to be deployed by the mid-1990s. Through an integrated network spanning the entire United States and its island territories, from Guam to Puerto Rico, WSR-88D will dramatically enhance our ability to safeguard life, property and commerce.

Rainfall Accumulation (click on image to see full size image)

Users of radar data have access to WSR-88D product via the NEXRAD Information Dissemination Service (NIDS) vendors. There are four NIDS vendors, each offering the full complement of WSR-88D products:

• Kavouras Incorporated
  6301 34th Avenue South
  Minneapolis, MN 55450-2979
• Unisys Weather Information Services
  P.O. Box 1226
  Kennett Square, PA 19348
• WSI Corporation
  4 Federal Street
  Billerica, MA 01821-5000
• Zephyr Weather Information Service, Inc.
  40 Washington Street
  Westbourough, MA 01581-0500
  
  
  

The following WSR-88D products are available:

• Reflectivity
• Composite Reflectivity
• Layer Composite Reflectivity
• Mean Radial Velocity
• Echo Tops
• One-Hour Rainfall Accumulation
• Three-Hour Rainfall Accumulation
• Storm Total Rainfall Accumulation
• Hourly Digital Rainfall Array
• Vertically Integrated Liquid Water
• Velocity Azimuth Display Wind Profile

Important advances in the science of meteorology, coupled with major new technological capabilities for observing and analyzing the atmosphere, will provide unprecedented weather service improvements in the next decade. The NWS of the 1990s and beyond will operate one of the most advanced hydrometeorological warning and forecast systems in the world.

October 1995
Prepared by: Allan Darling
National Implementation Staff
National Weather Service