Research Tools: Decision Support

NWS forecasters have a firehose of information directed at them, especially when there is a threat of severe weather. NSSL investigates methods and techniques to diagnose severe weather events more quickly and accurately.


NSSL developed and implemented the real-time Multi-Radar Multi-Sensor system in 2004, quickly and intelligently integrates data from multiple radar networks, surface and upper air observations, lightning detection systems, satellite and numerical weather prediction models. Numerous two-dimensional multiple-sensor products offer assistance for hail, wind, tornado, quantitative precipitation estimation forecasts, convection, icing, and turbulence diagnosis.

MRMS was transitioned into operations at the National Center for Environmental Prediction in 2014 and provides severe weather and precipitation products for improved decision-making capability within NOAA. The operational MRMS QPE products have high resolution and rapid updating capabilities. The products are also used for verification of satellite rain products and for verification of quantitative rain forecasts from numerical weather prediction models. MRMS serves as a powerful tool for the creation and evaluation of new techniques, strategies and applications to better QPE. As new concepts are developed, they can be tested by easily plugged in and out of MRMS. This process facilitates a rapid science-to-operations transition of new MRMS applications and products for flood and flash flood predictions and water resources management.

The MRMS system produces severe weather and precipitation products for improved decision-making capability to improve severe weather forecasts and warnings, hydrology, aviation, and numerical weather prediction.


In the 1990s, NSSL developed the Warning Decision Support System, to enhance NWS warning capabilities. NSSL continues to work on the next generation WDSS-II (Warning Decision Support System: Integrated Information/NMQ), a tool that quickly combines data streams from multiple radars, surface and upper air observations, lightning detection systems, and satellite and forecast models. This improved and expanded system will eventually be moved to National Weather Service operations as the Multi-Radar Multi-Sensor (MRMS) system, and will automatically produce severe weather and precipitation products for improved decision-making capability within NOAA.

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NSSL: On-Demand

NSSL: On-Demand was a web-based tool based on WDSS-II that helped confirm when and where severe weather occurred by mapping radar-detected circulations or hail on Google Earth satellite images. National Weather Service (NWS) forecast offices, including those affected by the April 27, 2011 tornado outbreak, used the images to plan post event damage surveys. Emergency responders used On-Demand to produce high-resolution street maps of affected areas, so they could more effectively begin rescue and recovery efforts and damage assessments.

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A weather-adaptive three-dimensional variational data assimilation (3DVAR) system from NSSL/CIMMS automatically detects and analyzes supercell thunderstorms. The 3DVAR system uses data from the national WSR-88D radar network and NCEP's North American Mesoscale model product to automatically locate regions of thunderstorm activity. It is able to identify deep rotating updrafts that indicate a supercell thunderstorm at 1 km resolution every five minutes in these regions.

Preliminary display


NSSL has more than ten NWS workstations—the Advanced Weather Interactive Processing System 2 (AWIPS2)—available for use in product evaluation. NSSL uses these AWIPS2 stations to test and demonstrate warning products and techniques that have been developed here that will be available in the NWS Forecast Office in the future.

NSSL Development Lab

NSSL's Development Lab includes four wall-mounted plasma screen displays and enough room for at least 10 workstations. A large round table occupies the middle of the room for lunchtime “brown bag” discussions and other meetings. Researchers, forecasters and developers are using the lab to evaluate new platforms and techniques in real-time as a team. The workstations in the lab can be quickly adapted for visualization and incorporation of unique data sources including dual-pol and phased array radars.