“Severe clear” hampered radar test

CASA radar being installed in Oklahoma

CASA radar being installed in Oklahoma

NSSL scientists have been waiting for severe weather to test algorithm techniques on Collaborative Adaptive Sensing of the Atmosphere (CASA) radars located in central Oklahoma. The pretty fall weather has not cooperated until early this morning when a line of thunderstorms rolled through the testbed bringing an end to the “severe clear.”

NSSL is participating in CASA to explore monitoring the lower atmosphere with a network of many short-wavelength (3cm) radars. These small and less expensive radars are spaced much closer together than those in the current operational radar network to provide data in blind spots caused by the curvature of the earth in the lowest 1km of the atmosphere.

The system of radars that are part of the Oklahoma testbed are spaced 30km from each other and are one-fifth the size of a NEXRAD radar.

NSSL researchers want to know if CASA data will allow the algorithms and/or meteorologists to better discern which storms with rotation signatures will develop tornadoes. Their hope is the algorithms will lead to a higher probability of detection, lower false alarm rates, and increased lead time. Eventually, the algorithm detections will be used to modify the scanning strategies of the radar based on the threat.

Fall data collection will continue through mid-October and is in preparation for Spring 2009 when NSSL will provide the processing and display of CASA products in the NOAA Hazardous Weather Testbed and National Weather Service Forecast Office (NWSFO) for forecaster evaluation. Data is already provided to the Norman NWSFO when the radars are active.

Background: CASA, the center for Collaborative Adaptive Sensing of the Atmosphere, is a prestigious National Science Foundation Engineering Center with over $40 million in federal, university, industry, and state funding. CASA is a collaboration among four academic partners: the University of Massachusetts (lead institution), the University of Oklahoma, Colorado State University, and the University of Puerto Rico. Other collaborating academic institutions are: the University of Delaware, the University of Virginia, and Rice University. Industry and government partners include: Raytheon, IBM, NOAA NSSL, Vaisala, Vieux and Associates, Texas Medical Center, OneNet, DeTect, Inc., NEWS 9 in Oklahoma, Micro-Ant, and National Research Institute for Earth Science and Disaster Prevention (NIED) of Japan.

Significance: CASA radars have the potential to significantly reduce tornado warning false-alarms, improve precipitation estimates for flood prediction, detect humidity and temperature variables and provide a vastly superior understanding of how winds carry chemical, radiological or biological hazards. All of these will save lives and reduce property losses.

More information: http://www.nssl.noaa.gov/research/radar/dcas.php