The new Radar, or NEXRAD for Next Generation Radar (officially WSR-88D), provides forecasters with a detailed look at storms through reflectivity and velocity displays. Reflectivity indicates rainfall or precipitation intensity and velocity displays the speed and direction of the winds within the storm.

Through the Doppler Effect, a physical phenomena marked by a change in frequency depending on the motion of an object toward or away from a point, the radar can give a picture of the winds within a storm. If, within a small area, high winds toward the radar are adjacent to high winds away from the radar, a circulation has developed and forecasters prepare to issue a warning. With this capability, tornado warning lead times have increased in the last 10 years from less than 5 minutes to nearly 12 minutes (NWS).

Phased Array Radar - NSSL will soon begin adapting SPY-1 radar technology for use in spotting severe weather

The Joint Polarization Experiment (JPOLE)
Dual Polarization Q&A
Polarimetric Radar Case Studies

NSSL Accomplishments with Doppler Radar

NSSL Doppler Radar and Remote Sensing Group

New England Forecasting Pilot Program - studying high-resolution radar wind retrieval and assimilation using WSR-88D Level-II data

Study of Tornadic Vortex Signatures by CIMMS scientist Jeff Trapp

Shared Mobile Atmospheric Teaching and Research Radar

The National Weather Service's Doppler radar, the WSR-88D, has three parts: Radar Data Aquisition (RDA), Radar Product Generator (RPG), and Principle User Processor (PUP).

NSSL is now working to design and implement an open systems computing environment for these three functional areas of the radar. Scientists are also working to add polarimetric capability for future 88D upgrades.

Open RDA Project
Open Systems RPG
Open Systems PUP

Additional Radar Sites:

Why radar can't (usually) see tornadoes

Radar Meteorology from Weather World 2010

NEXRAD Radar Operations Center

Updated September 16, 2004